Squamous cell carcinoma
Encyclopedia
Squamous cell carcinoma (SCC or SqCC), occasionally rendered as "squamous-cell carcinoma", is a histologically
distinct form of cancer
. It arises from the uncontrolled multiplication of malignant
cells
deriving from epithelium
, or showing particular cytological or tissue
architectural characteristics of squamous cell differentiation
, such as the presence of keratin
, tonofilament bundles, and/or desmosomes).
Squamous cell carcinoma
is one of the most common cancers in humans and other animals, and usually arises from mutated ectoderm
al or endoderm
al cells lining body cavities. Therefore, it can develop in a large number of organs
and tissues, including the skin
, lip
s, mouth
, esophagus
, urinary bladder
, prostate
, lung
, vagina
, and cervix
, among others.
Despite the common name, squamous cell carcinomas arising in different body sites can show tremendous differences in their presenting signs
and symptom
s, natural history, prognosis
, and response to treatment.
Though the use of these terms has been decreasing in the literature, SqCC is still sometimes referred to as "epidermoid carcinoma" and "squamous cell epithelioma".
The International Classification of Diseases for Oncology (ICD-O) system lists a number of morphological
subtypes and variants of malignant
squamous cell neoplasms, including:
Other variants of squamous cell carcinoma are recognized under other systems, such as:
, and it is diagnosed when the tumor has not yet penetrated the basement membrane
or other delimiting structure to invade adjacent tissues. Once the lesion has grown and progressed to the point where it has breached, penetrated, and infiltrated adjacent structures, it is referred to as "invasive" squamous cell carcinoma. Once a carcinoma becomes invasive, it is able to spread to other organs and cause a metastasis
, or "secondary tumor", to form.
SCC of the skin begins as a small nodule and as it enlarges the center becomes necrotic and sloughs and the nodule turns into an ulcer.
About one-third of lingual and mucosal tumors metastasize before diagnosis (these are often related to tobacco and alcohol use)
, lung, fingers, and anogenital region.
(after basal cell carcinoma
but more common than melanoma
). It usually occurs in areas exposed to the sun. Sunlight exposure and immunosuppression
are risk factors
for SqCC of the skin, with chronic sun exposure being the strongest environmental risk factor. The risk of metastasis
is low, but is much higher than with basal cell carcinoma. Squamous cell cancers of the lip and ears have high rates of local recurrence and distant metastasis (20–50%). Squamous cell cancers of the skin in individuals on immunotherapy or suffering from lymphoproliferative disorders (i.e. leukemia
) tend to be much more aggressive, regardless of their location.
Squamous cell carcinoma are generally treated by surgical excision
or Mohs surgery
. Non-surgical options for the treatment of cutaneous SqCC include topical chemotherapy
, topical immune response modifiers, photodynamic therapy
(PDT), radiotherapy, and systemic chemotherapy. The use of topical therapy, such as Imiquimod cream and PDT is generally limited to premalignant (i.e., AKs) and in situ lesions. Radiation therapy is a primary treatment option for patients in whom surgery is not feasible and is an adjuvant
therapy for those with metastatic or high-risk cutaneous SqCC. At this time, systemic chemotherapy is used exclusively for patients with metastatic disease.
(cancer of the mouth, nasal cavity, nasopharynx, throat and associated structures) are due to squamous cell carcinoma. Symptoms may include a poorly healing mouth ulcer
, a hoarse voice or other persistent problems in the area. Treatment is usually with surgery
(which may be extensive) and radiotherapy. Risk factors include smoking
, alcohol consumption
and hematopoietic stem cell transplantation. In addition, recent studies show that about 25% of mouth and 35% of throat cancers are associated with HPV. The 5 year disease free survival rate for HPV positive cancer is significantly higher when appropriately treated with surgery, radiation and chemotherapy as compared to non-HPV positive cancer, substantiated by multiple studies including research conducted by Dr. Maureen Gillison, et al. of Johns Hopkins Sidney Kimmel Cancer Center.
may be due to either squamous cell carcinoma (ESCC) or adenocarcinoma
(EAC). SCCs tend to occur closer to the mouth, while adenocarcinomas occur closer to the stomach. Dysphagia
(difficulty swallowing, solids worse than liquids) and odynophagia
are common initial symptoms. If the disease is localized, esophagectomy
may offer the possibility of a cure. If the disease has spread, chemotherapy
and radiotherapy are commonly used.
(PTHrP), resulting in hypercalcemia.
) is found on the penis, it is called erythroplasia of Queyrat
. This type of cancer responds very well to imiquimod
.
, squamous cell carcinoma is very aggressive in nature. It is difficult to detect as there is no increase in prostate specific antigen
levels seen; meaning that the cancer is often diagnosed at an advanced stage.
.
is often squamous cell carcinoma.
. For the skin, look under skin biopsy
.
The pathological appearance of a squamous cell cancer varies with the depth of the biopsy. For that reason, a biopsy including the subcutaneous tissue and basalar epithelium, to the surface is necessary for correct diagnosis. The performance of a shave biopsy (see skin biopsy
) might not acquire enough information for a diagnosis. An inadequate biopsy might be read as actinic keratosis
with follicular involvement. A deeper biopsy down to the dermis or subcutaneous tissue might reveal the true cancer. An excision biopsy is ideal, but not practical in most cases. An incisional or punch biopsy is preferred. A shave biopsy is least ideal, especially if only the superficial portion is acquired.
may prevent skin cancer
.
medication. Surgical excision with a free margin of healthy tissue is a frequent treatment modality. Radiotherapy, given as external beam radiotherapy
or as brachytherapy
(internal radiotherapy), can also be used to treat squamous cell carcinomas.
Mohs surgery
is frequently utilized; considered the treatment of choice for squamous cell carcinoma of the skin, physicians have also utilized the method for the treatment of squamous cell carcinoma of the mouth, throat, and neck. An equivalent method of the CCPDMA
standards can be utilized by a pathologist in the absence of a Mohs-trained physician. Radiation
therapy often used afterward in high risk cancer or patient types.
Electrodesiccation and curettage or EDC can be done on selected squamous cell carcinoma of the skin. In areas where SCC's are known to be non-aggressive, and where the patient is not immunosuppressed, EDC can be performed with good to adequate cure rate.
Imiquimod
(Aldara) has been used with success for squamous cell carcinoma in situ of the skin and the penis, but the morbidity and discomfort of the treatment is severe. An advantage is the cosmetic result: after treatment, the skin resembles normal skin without the usual scarring and morbidity associated with standard excision. Imiquimod is not FDA-approved for any squamous cell carcinoma.
In 2007, Australian biopharmaceutical company Clinuvel Pharmaceuticals Limited began clinical trials with an experimental treatment, a melanocyte-stimulating hormone
called afamelanotide
(formerly CUV1647) to provide photoprotection
for organ transplant patients against squamous cell carcinoma of the skin and actinic keratosis
.
Histology
Histology is the study of the microscopic anatomy of cells and tissues of plants and animals. It is performed by examining cells and tissues commonly by sectioning and staining; followed by examination under a light microscope or electron microscope...
distinct form of cancer
Cancer
Cancer , known medically as a malignant neoplasm, is a large group of different diseases, all involving unregulated cell growth. In cancer, cells divide and grow uncontrollably, forming malignant tumors, and invade nearby parts of the body. The cancer may also spread to more distant parts of the...
. It arises from the uncontrolled multiplication of malignant
Malignant
Malignancy is the tendency of a medical condition, especially tumors, to become progressively worse and to potentially result in death. Malignancy in cancers is characterized by anaplasia, invasiveness, and metastasis...
cells
Cell (biology)
The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos....
deriving from epithelium
Epithelium
Epithelium is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. Epithelial tissues line the cavities and surfaces of structures throughout the body, and also form many glands. Functions of epithelial cells include secretion, selective...
, or showing particular cytological or tissue
Tissue (biology)
Tissue is a cellular organizational level intermediate between cells and a complete organism. A tissue is an ensemble of cells, not necessarily identical, but from the same origin, that together carry out a specific function. These are called tissues because of their identical functioning...
architectural characteristics of squamous cell differentiation
Cellular differentiation
In developmental biology, cellular differentiation is the process by which a less specialized cell becomes a more specialized cell type. Differentiation occurs numerous times during the development of a multicellular organism as the organism changes from a simple zygote to a complex system of...
, such as the presence of keratin
Keratin
Keratin refers to a family of fibrous structural proteins. Keratin is the key of structural material making up the outer layer of human skin. It is also the key structural component of hair and nails...
, tonofilament bundles, and/or desmosomes).
Squamous cell carcinoma
Carcinoma
Carcinoma is the medical term for the most common type of cancer occurring in humans. Put simply, a carcinoma is a cancer that begins in a tissue that lines the inner or outer surfaces of the body, and that generally arises from cells originating in the endodermal or ectodermal germ layer during...
is one of the most common cancers in humans and other animals, and usually arises from mutated ectoderm
Ectoderm
The "ectoderm" is one of the three primary germ cell layers in the very early embryo. The other two layers are the mesoderm and endoderm , with the ectoderm as the most exterior layer...
al or endoderm
Endoderm
Endoderm is one of the three primary germ cell layers in the very early embryo. The other two layers are the ectoderm and mesoderm , with the endoderm as the intermost layer...
al cells lining body cavities. Therefore, it can develop in a large number of organs
Organ (anatomy)
In biology, an organ is a collection of tissues joined in structural unit to serve a common function. Usually there is a main tissue and sporadic tissues . The main tissue is the one that is unique for the specific organ. For example, main tissue in the heart is the myocardium, while sporadic are...
and tissues, including the skin
Skin
-Dermis:The dermis is the layer of skin beneath the epidermis that consists of connective tissue and cushions the body from stress and strain. The dermis is tightly connected to the epidermis by a basement membrane. It also harbors many Mechanoreceptors that provide the sense of touch and heat...
, lip
Lip
Lips are a visible body part at the mouth of humans and many animals. Lips are soft, movable, and serve as the opening for food intake and in the articulation of sound and speech...
s, mouth
Mouth
The mouth is the first portion of the alimentary canal that receives food andsaliva. The oral mucosa is the mucous membrane epithelium lining the inside of the mouth....
, esophagus
Esophagus
The esophagus is an organ in vertebrates which consists of a muscular tube through which food passes from the pharynx to the stomach. During swallowing, food passes from the mouth through the pharynx into the esophagus and travels via peristalsis to the stomach...
, urinary bladder
Urinary bladder
The urinary bladder is the organ that collects urine excreted by the kidneys before disposal by urination. A hollow muscular, and distensible organ, the bladder sits on the pelvic floor...
, prostate
Prostate
The prostate is a compound tubuloalveolar exocrine gland of the male reproductive system in most mammals....
, lung
Lung
The lung is the essential respiration organ in many air-breathing animals, including most tetrapods, a few fish and a few snails. In mammals and the more complex life forms, the two lungs are located near the backbone on either side of the heart...
, vagina
Vagina
The vagina is a fibromuscular tubular tract leading from the uterus to the exterior of the body in female placental mammals and marsupials, or to the cloaca in female birds, monotremes, and some reptiles. Female insects and other invertebrates also have a vagina, which is the terminal part of the...
, and cervix
Cervix
The cervix is the lower, narrow portion of the uterus where it joins with the top end of the vagina. It is cylindrical or conical in shape and protrudes through the upper anterior vaginal wall...
, among others.
Despite the common name, squamous cell carcinomas arising in different body sites can show tremendous differences in their presenting signs
Medical sign
A medical sign is an objective indication of some medical fact or characteristic that may be detected by a physician during a physical examination of a patient....
and symptom
Symptom
A symptom is a departure from normal function or feeling which is noticed by a patient, indicating the presence of disease or abnormality...
s, natural history, prognosis
Prognosis
Prognosis is a medical term to describe the likely outcome of an illness.When applied to large statistical populations, prognostic estimates can be very accurate: for example the statement "45% of patients with severe septic shock will die within 28 days" can be made with some confidence, because...
, and response to treatment.
Though the use of these terms has been decreasing in the literature, SqCC is still sometimes referred to as "epidermoid carcinoma" and "squamous cell epithelioma".
Classification
Cancer can be considered a very large and exceptionally heterogeneous family of malignant diseases, with squamous cell carcinomas comprising one of the largest subsets.The International Classification of Diseases for Oncology (ICD-O) system lists a number of morphological
Morphology (biology)
In biology, morphology is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features....
subtypes and variants of malignant
Malignant
Malignancy is the tendency of a medical condition, especially tumors, to become progressively worse and to potentially result in death. Malignancy in cancers is characterized by anaplasia, invasiveness, and metastasis...
squamous cell neoplasms, including:
- Papillary carcinoma (Code 8050/3)
- Verrucous squamous cell carcinoma (Code 8051/3)
- Papillary squamous cell carcinoma (Code 8052/3)
- Squamous cell carcinomaSquamous cell carcinomaSquamous cell carcinoma , occasionally rendered as "squamous-cell carcinoma", is a histologically distinct form of cancer. It arises from the uncontrolled multiplication of malignant cells deriving from epithelium, or showing particular cytological or tissue architectural characteristics of...
(Code 8270/3) - Large cell keratinizing squamous cell carcinoma (Code 8071/3)
- Large cell keratinizing squamous cell carcinoma (Code 8072/3)
- Small cell keratinizing squamous cell carcinoma (Code 8073/3)
- Spindle cell squamous cell carcinomaSpindle cell squamous cell carcinomaSpindle-cell squamous-cell carcinoma is a cutaneous condition, a subtype of squamous-cell carcinoma, characterized by spindle-shaped atypical cells.- See also :* Pigmented spindle cell nevus...
(Code 8074/3) - Adenoid/pseudoglandular squamous cell carcinoma (Code 8075/3)
- Intraepidermal squamous cell carcinoma (Code 8081/3)
- Lymphoepithelial carcinoma (Code 8082/3)
Other variants of squamous cell carcinoma are recognized under other systems, such as:
- Basaloid squamous cell carcinomaBasaloid squamous cell carcinomaBasaloid squamous-cell carcinoma is a cutaneous condition, a subtype of squamous-cell carcinoma, a virulent form characterized by a predilection for the tongue base....
- Clear-cell squamous cell carcinoma
- KeratoacanthomaKeratoacanthomaKeratoacanthoma is a common low-grade skin tumour that is believed to originate from the neck of the hair follicle. Many pathologists consider it to be a form of squamous cell carcinoma...
- Signet-ring-cell squamous-cell carcinoma
Terminology
All squamous cell carcinoma lesions are thought to begin via the repeated, uncontrolled division of cancer stem cells of epithelial lineage or characteristics. Accumulation of these cancer cells cause a microscopic focus of abnormal cells that are, at least initially, locally confined within the specific tissue in which the progenitor cell resided. This condition is called squamous cell carcinoma in situCarcinoma in situ
Carcinoma in situ is an early form of cancer that is defined by the absence of invasion of tumor cells into the surrounding tissue, usually before penetration through the basement membrane. In other words, the neoplastic cells proliferate in their normal habitat, hence the name "in situ"...
, and it is diagnosed when the tumor has not yet penetrated the basement membrane
Basement membrane
The basement membrane is a thin sheet of fibers that underlies the epithelium, which lines the cavities and surfaces of organs including skin, or the endothelium, which lines the interior surface of blood vessels.- Composition :...
or other delimiting structure to invade adjacent tissues. Once the lesion has grown and progressed to the point where it has breached, penetrated, and infiltrated adjacent structures, it is referred to as "invasive" squamous cell carcinoma. Once a carcinoma becomes invasive, it is able to spread to other organs and cause a metastasis
Metastasis
Metastasis, or metastatic disease , is the spread of a disease from one organ or part to another non-adjacent organ or part. It was previously thought that only malignant tumor cells and infections have the capacity to metastasize; however, this is being reconsidered due to new research...
, or "secondary tumor", to form.
Related conditions
- Basal cell carcinomaBasal cell carcinomaBasal-cell carcinoma is the most common type of skin cancer. It rarely metastasizes or kills. However, because it can cause significant destruction and disfigurement by invading surrounding tissues, it is still considered malignant. Statistically, approximately 3 out of 10 Caucasians may develop a...
- Bowen's diseaseBowen's diseaseBowen's disease is a neoplastic skin disease, it can be considered as an early stage or intraepidermal form of squamous cell carcinoma. It was named after Mark Bowen...
is a sunlight-induced skin disease, and is considered to be an early form of squamous cell carcinoma. - Erythroplasia of QueyratErythroplasia of QueyratErythroplasia of Queyrat is a squamous cell carcinoma in situ of the glans penis.Like Bowen's Disease, it is associated with Human Papilloma Virus 16 and is a precursor for invasive squamous cell carcinoma.It is named for Louis Queyrat....
- KeratoacanthomaKeratoacanthomaKeratoacanthoma is a common low-grade skin tumour that is believed to originate from the neck of the hair follicle. Many pathologists consider it to be a form of squamous cell carcinoma...
is a low-grade malignancy of the skin. It originates in the pilo-sebaceous glandsSebaceous glandThe sebaceous glands are microscopic glands in the skin that secrete an oily/waxy matter, called sebum, to lubricate and waterproof the skin and hair of mammals...
, and is similar in clinical presentation and microscopic analysis to squamous cell carcinoma, except that it contains a central keratinKeratinKeratin refers to a family of fibrous structural proteins. Keratin is the key of structural material making up the outer layer of human skin. It is also the key structural component of hair and nails...
plug. Statistically, it is less likely to become invasive than squamous cell carcinoma. - Marjolin's ulcerMarjolin's ulcerMarjolin's ulcer refers to an aggressive ulcerating squamous cell carcinoma presenting in an area of previously traumatized, chronically inflamed, or scarred skin...
is a type of squamous cell carcinoma that arises from a non-healing ulcer or burn wound. - MelanomaMelanomaMelanoma is a malignant tumor of melanocytes. Melanocytes are cells that produce the dark pigment, melanin, which is responsible for the color of skin. They predominantly occur in skin, but are also found in other parts of the body, including the bowel and the eye...
Signs and symptoms
Symptoms are highly variable depending on the involved organs.SCC of the skin begins as a small nodule and as it enlarges the center becomes necrotic and sloughs and the nodule turns into an ulcer.
- The lesion caused by SCC is often asymptomatic
- Ulcer or reddish skin plaque that is slow growing
- Intermittent bleeding from the tumor, especially on the lip
- The clinical appearance is highly variable
- Usually the tumor presents as an ulcerated lesion with hard, raised edges
- The tumor may be in the form of a hard plaque or a papulePapuleA papule is a circumscribed, solid elevation of skin with no visible fluid, varying in size from a pinhead to 1 cm.With regard to the quote "...varying in size from a pinhead to 1cm," depending on which text is referenced, some authors state the cutoff between a papule and a plaque as 0.5cm,...
, often with an opalescent quality, with tiny blood vesselsTelangiectasiaTelangiectasias /tɛ.læn.dʒiː'ɛk.teɪ.ʃi:ə/ are small dilated blood vessels near the surface of the skin or mucous membranes, measuring between 0.5 and 1 millimeter in diameter. They can develop anywhere on the body but are commonly seen on the face around the nose, cheeks, and chin... - The tumor can lie below the level of the surrounding skin, and eventually ulcerates and invades the underlying tissue
- The tumor commonly presents on sun-exposed areas (e.g. back of the hand, scalp, lip, and superior surface of pinna)
- On the lip, the tumor forms a small ulcer, which fails to heal and bleeds intermittently
- Evidence of chronic skin photodamage, such as multiple actinic keratoses (solar keratoses)
- The tumor grows relatively slowly
- Unlike basal cell carcinoma (BCC), squamous cell carcinoma (SCC) has a substantial risk of metastasisMetastasisMetastasis, or metastatic disease , is the spread of a disease from one organ or part to another non-adjacent organ or part. It was previously thought that only malignant tumor cells and infections have the capacity to metastasize; however, this is being reconsidered due to new research...
- Risk of metastasis is higher in SCC arising in scars, on the lower lips or mucosa, and occurring in immunosuppressed patients.
About one-third of lingual and mucosal tumors metastasize before diagnosis (these are often related to tobacco and alcohol use)
Human papilloma virus
Human papilloma virus (HPV) has been associated with SqCC of the oropharynxHPV-positive oropharyngeal cancer
Human papillomavirus -positive oropharyngeal cancer also known as HPV16+ oropharyngeal cancer or HPV+ OPC is a recognized subtype of Oropharyngeal squamous cell carcinomas , associated with the HPV type 16 virus.-Causes:...
, lung, fingers, and anogenital region.
Skin
Squamous cell carcinoma is the second-most common cancer of the skinSkin cancer
Skin neoplasms are skin growths with differing causes and varying degrees of malignancy. The three most common malignant skin cancers are basal cell cancer, squamous cell cancer, and melanoma, each of which is named after the type of skin cell from which it arises...
(after basal cell carcinoma
Basal cell carcinoma
Basal-cell carcinoma is the most common type of skin cancer. It rarely metastasizes or kills. However, because it can cause significant destruction and disfigurement by invading surrounding tissues, it is still considered malignant. Statistically, approximately 3 out of 10 Caucasians may develop a...
but more common than melanoma
Melanoma
Melanoma is a malignant tumor of melanocytes. Melanocytes are cells that produce the dark pigment, melanin, which is responsible for the color of skin. They predominantly occur in skin, but are also found in other parts of the body, including the bowel and the eye...
). It usually occurs in areas exposed to the sun. Sunlight exposure and immunosuppression
Immunosuppression
Immunosuppression involves an act that reduces the activation or efficacy of the immune system. Some portions of the immune system itself have immuno-suppressive effects on other parts of the immune system, and immunosuppression may occur as an adverse reaction to treatment of other...
are risk factors
Risk factors
A risk factor is a concept in finance theory such as the CAPM, APT and other theories that use pricing kernels. In these models, the rate of return of an asset is a random variable whose realization in any time period is a linear combination of other random variables plus a disturbance term or...
for SqCC of the skin, with chronic sun exposure being the strongest environmental risk factor. The risk of metastasis
Metastasis
Metastasis, or metastatic disease , is the spread of a disease from one organ or part to another non-adjacent organ or part. It was previously thought that only malignant tumor cells and infections have the capacity to metastasize; however, this is being reconsidered due to new research...
is low, but is much higher than with basal cell carcinoma. Squamous cell cancers of the lip and ears have high rates of local recurrence and distant metastasis (20–50%). Squamous cell cancers of the skin in individuals on immunotherapy or suffering from lymphoproliferative disorders (i.e. leukemia
Leukemia
Leukemia or leukaemia is a type of cancer of the blood or bone marrow characterized by an abnormal increase of immature white blood cells called "blasts". Leukemia is a broad term covering a spectrum of diseases...
) tend to be much more aggressive, regardless of their location.
Squamous cell carcinoma are generally treated by surgical excision
Excision
Excision is the alias of Jeff Abel, a dubstep DJ and music boss from British Columbia, Canada. He frequently works with fellow Canadian dubstep producers Datsik and Downlink. As one of the first dubstep producers and DJs in North America, he has played a significant role in the genre's growth in...
or Mohs surgery
Mohs surgery
Mohs surgery, also known as chemosurgery, created by a general surgeon, Dr. Frederic E. Mohs, is microscopically controlled surgery used to treat common types of skin cancer. It is one of the many methods of obtaining complete margin control during removal of a skin cancer using frozen section...
. Non-surgical options for the treatment of cutaneous SqCC include topical chemotherapy
Chemotherapy
Chemotherapy is the treatment of cancer with an antineoplastic drug or with a combination of such drugs into a standardized treatment regimen....
, topical immune response modifiers, photodynamic therapy
Photodynamic therapy
Photodynamic therapy is used clinically to treat a wide range of medical conditions, including malignant cancers, and is recognised as a treatment strategy which is both minimally invasive and minimally toxic...
(PDT), radiotherapy, and systemic chemotherapy. The use of topical therapy, such as Imiquimod cream and PDT is generally limited to premalignant (i.e., AKs) and in situ lesions. Radiation therapy is a primary treatment option for patients in whom surgery is not feasible and is an adjuvant
Adjuvant
An adjuvant is a pharmacological or immunological agent that modifies the effect of other agents, such as a drug or vaccine, while having few if any direct effects when given by itself...
therapy for those with metastatic or high-risk cutaneous SqCC. At this time, systemic chemotherapy is used exclusively for patients with metastatic disease.
Head and neck cancer
Ninety percent of cases of head and neck cancerHead and neck cancer
Head and neck cancer refers to a group of biologically similar cancers that start in the upper aerodigestive tract, including the lip, oral cavity , nasal cavity , paranasal sinuses, pharynx, and larynx. 90% of head and neck cancers are squamous cell carcinomas , originating from the mucosal lining...
(cancer of the mouth, nasal cavity, nasopharynx, throat and associated structures) are due to squamous cell carcinoma. Symptoms may include a poorly healing mouth ulcer
Mouth ulcer
A mouth or oral ulcer is an open sore in the mouth, or rarely a break in the mucous membrane or the epithelium on the lips or surrounding the mouth. The types of mouth ulcers are diverse, with a multitude of associated causes including: physical abrasion, acidic fruit, infection, other medical...
, a hoarse voice or other persistent problems in the area. Treatment is usually with surgery
Surgery
Surgery is an ancient medical specialty that uses operative manual and instrumental techniques on a patient to investigate and/or treat a pathological condition such as disease or injury, or to help improve bodily function or appearance.An act of performing surgery may be called a surgical...
(which may be extensive) and radiotherapy. Risk factors include smoking
Tobacco smoking
Tobacco smoking is the practice where tobacco is burned and the resulting smoke is inhaled. The practice may have begun as early as 5000–3000 BCE. Tobacco was introduced to Eurasia in the late 16th century where it followed common trade routes...
, alcohol consumption
Alcoholic beverage
An alcoholic beverage is a drink containing ethanol, commonly known as alcohol. Alcoholic beverages are divided into three general classes: beers, wines, and spirits. They are legally consumed in most countries, and over 100 countries have laws regulating their production, sale, and consumption...
and hematopoietic stem cell transplantation. In addition, recent studies show that about 25% of mouth and 35% of throat cancers are associated with HPV. The 5 year disease free survival rate for HPV positive cancer is significantly higher when appropriately treated with surgery, radiation and chemotherapy as compared to non-HPV positive cancer, substantiated by multiple studies including research conducted by Dr. Maureen Gillison, et al. of Johns Hopkins Sidney Kimmel Cancer Center.
Esophagus
Esophageal cancerEsophageal cancer
Esophageal cancer is malignancy of the esophagus. There are various subtypes, primarily squamous cell cancer and adenocarcinoma . Squamous cell cancer arises from the cells that line the upper part of the esophagus...
may be due to either squamous cell carcinoma (ESCC) or adenocarcinoma
Adenocarcinoma
Adenocarcinoma is a cancer of an epithelium that originates in glandular tissue. Epithelial tissue includes, but is not limited to, the surface layer of skin, glands and a variety of other tissue that lines the cavities and organs of the body. Epithelium can be derived embryologically from...
(EAC). SCCs tend to occur closer to the mouth, while adenocarcinomas occur closer to the stomach. Dysphagia
Dysphagia
Dysphagia is the medical term for the symptom of difficulty in swallowing. Although classified under "symptoms and signs" in ICD-10, the term is sometimes used as a condition in its own right. Sufferers are sometimes unaware of their dysphagia....
(difficulty swallowing, solids worse than liquids) and odynophagia
Odynophagia
Odynophagia is painful swallowing, in the mouth or esophagus. It can occur with or without dysphagia, or difficult swallowing....
are common initial symptoms. If the disease is localized, esophagectomy
Esophagectomy
Esophagectomy or Oesophagectomy is the surgical removal of all or part of the esophagus .-Purpose:...
may offer the possibility of a cure. If the disease has spread, chemotherapy
Chemotherapy
Chemotherapy is the treatment of cancer with an antineoplastic drug or with a combination of such drugs into a standardized treatment regimen....
and radiotherapy are commonly used.
Lung
When associated with the lung, it often causes ectopic production of parathyroid hormone-related proteinParathyroid hormone-related protein
Parathyroid hormone-related protein is a protein member of the parathyroid hormone family. It is occasionally secreted by cancer cells . However, it also has normal functions.- Function :PTHrP acts as an endocrine, autocrine, paracrine, and intracrine hormone...
(PTHrP), resulting in hypercalcemia.
Penis
When squamous cell carcinoma in situ (Bowen's diseaseBowen's disease
Bowen's disease is a neoplastic skin disease, it can be considered as an early stage or intraepidermal form of squamous cell carcinoma. It was named after Mark Bowen...
) is found on the penis, it is called erythroplasia of Queyrat
Erythroplasia of Queyrat
Erythroplasia of Queyrat is a squamous cell carcinoma in situ of the glans penis.Like Bowen's Disease, it is associated with Human Papilloma Virus 16 and is a precursor for invasive squamous cell carcinoma.It is named for Louis Queyrat....
. This type of cancer responds very well to imiquimod
Imiquimod
Imiquimod is a prescription medication that acts as an immune response modifier. It is marketed by Meda AB, Graceway Pharmaceuticals and iNova Pharmaceuticals under the trade names Aldara and Zyclara, and by Mochida as Beselna. It is also referred to as R-837.- History :The original FDA approval...
.
Prostate
When associated with the prostateProstate
The prostate is a compound tubuloalveolar exocrine gland of the male reproductive system in most mammals....
, squamous cell carcinoma is very aggressive in nature. It is difficult to detect as there is no increase in prostate specific antigen
Prostate specific antigen
Prostate-specific antigen also known as gamma-seminoprotein or kallikrein-3 is a glycoprotein that in humans is encoded by the KLK3 gene. KLK3 is a member of the kallikrein-related peptidase family that are secreted by the epithelial cells of the prostate gland...
levels seen; meaning that the cancer is often diagnosed at an advanced stage.
Vagina and cervix
Vaginal squamous cell carcinoma spreads slowly and usually stays near the vagina, but may spread to the lungs and liver. This is the most common type of vaginal cancerVaginal cancer
Vaginal cancer is any type of cancer that forms in the tissues of the vagina. Primary vaginal cancer is rare in the general population of women and is usually a squamous carcinoma. Metastases are more common. Vaginal cancer occurs more often in women over age 50, but can occur at any age, even in...
.
Bladder
Most bladder cancer is transitional cell, but bladder cancer associated with SchistosomiasisSchistosomiasis
Schistosomiasis is a parasitic disease caused by several species of trematodes , a parasitic worm of the genus Schistosoma. Snails often act as an intermediary agent for the infectious diseases until a new human host is found...
is often squamous cell carcinoma.
Diagnosis
Diagnosis is via a biopsyBiopsy
A biopsy is a medical test involving sampling of cells or tissues for examination. It is the medical removal of tissue from a living subject to determine the presence or extent of a disease. The tissue is generally examined under a microscope by a pathologist, and can also be analyzed chemically...
. For the skin, look under skin biopsy
Skin biopsy
Skin biopsy is a biopsy technique in which a skin lesion is removed and sent to the pathologist to render a microscopic diagnosis. It is usually done under local anesthetic in a physician's office, and results are often available in 4 to 10 days. It is commonly performed by dermatologists. Skin...
.
The pathological appearance of a squamous cell cancer varies with the depth of the biopsy. For that reason, a biopsy including the subcutaneous tissue and basalar epithelium, to the surface is necessary for correct diagnosis. The performance of a shave biopsy (see skin biopsy
Skin biopsy
Skin biopsy is a biopsy technique in which a skin lesion is removed and sent to the pathologist to render a microscopic diagnosis. It is usually done under local anesthetic in a physician's office, and results are often available in 4 to 10 days. It is commonly performed by dermatologists. Skin...
) might not acquire enough information for a diagnosis. An inadequate biopsy might be read as actinic keratosis
Actinic keratosis
Actinic keratosis is a premalignant condition of thick, scaly, or crusty patches of skin. It is more common in fair-skinned people. It is associated with those who are frequently exposed to the sun, as it is usually accompanied by solar damage...
with follicular involvement. A deeper biopsy down to the dermis or subcutaneous tissue might reveal the true cancer. An excision biopsy is ideal, but not practical in most cases. An incisional or punch biopsy is preferred. A shave biopsy is least ideal, especially if only the superficial portion is acquired.
Prevention
Appropriate clothing, avoidance of intense sun exposure and sunscreenSunscreen
Sunblock is a lotion, spray, gel or other topical product that absorbs or reflects some of the sun's ultraviolet radiation on the skin exposed to sunlight and thus helps protect against sunburn...
may prevent skin cancer
Skin cancer
Skin neoplasms are skin growths with differing causes and varying degrees of malignancy. The three most common malignant skin cancers are basal cell cancer, squamous cell cancer, and melanoma, each of which is named after the type of skin cell from which it arises...
.
Management
Most squamous cell carcinomas are removed with surgery. A few selected cases are treated with topicalTopical
In medicine, a topical medication is applied to body surfaces such as the skin or mucous membranes such as the vagina, anus, throat, eyes and ears.Many topical medications are epicutaneous, meaning that they are applied directly to the skin...
medication. Surgical excision with a free margin of healthy tissue is a frequent treatment modality. Radiotherapy, given as external beam radiotherapy
External beam radiotherapy
External beam radiotherapy or teletherapy is the most common form of radiotherapy. The patient sits or lies on a couch and an external source of radiation is pointed at a particular part of the body...
or as brachytherapy
Brachytherapy
Brachytherapy , also known as internal radiotherapy, sealed source radiotherapy, curietherapy or endocurietherapy, is a form of radiotherapy where a radiation source is placed inside or next to the area requiring treatment...
(internal radiotherapy), can also be used to treat squamous cell carcinomas.
Mohs surgery
Mohs surgery
Mohs surgery, also known as chemosurgery, created by a general surgeon, Dr. Frederic E. Mohs, is microscopically controlled surgery used to treat common types of skin cancer. It is one of the many methods of obtaining complete margin control during removal of a skin cancer using frozen section...
is frequently utilized; considered the treatment of choice for squamous cell carcinoma of the skin, physicians have also utilized the method for the treatment of squamous cell carcinoma of the mouth, throat, and neck. An equivalent method of the CCPDMA
CCPDMA
CCPDMA is the acronym for "complete circumferential peripheral and deep margin assessment". It is the preferred method for the removal of certain cancers, especially skin cancers.A classical example of CCPDMA is Mohs surgery...
standards can be utilized by a pathologist in the absence of a Mohs-trained physician. Radiation
Radiation
In physics, radiation is a process in which energetic particles or energetic waves travel through a medium or space. There are two distinct types of radiation; ionizing and non-ionizing...
therapy often used afterward in high risk cancer or patient types.
Electrodesiccation and curettage or EDC can be done on selected squamous cell carcinoma of the skin. In areas where SCC's are known to be non-aggressive, and where the patient is not immunosuppressed, EDC can be performed with good to adequate cure rate.
Imiquimod
Imiquimod
Imiquimod is a prescription medication that acts as an immune response modifier. It is marketed by Meda AB, Graceway Pharmaceuticals and iNova Pharmaceuticals under the trade names Aldara and Zyclara, and by Mochida as Beselna. It is also referred to as R-837.- History :The original FDA approval...
(Aldara) has been used with success for squamous cell carcinoma in situ of the skin and the penis, but the morbidity and discomfort of the treatment is severe. An advantage is the cosmetic result: after treatment, the skin resembles normal skin without the usual scarring and morbidity associated with standard excision. Imiquimod is not FDA-approved for any squamous cell carcinoma.
In 2007, Australian biopharmaceutical company Clinuvel Pharmaceuticals Limited began clinical trials with an experimental treatment, a melanocyte-stimulating hormone
Melanocyte-stimulating hormone
The melanocyte-stimulating hormones are a class of peptide hormones that are produced by cells in the intermediate lobe of the pituitary gland...
called afamelanotide
Afamelanotide
Afamelanotide developed at the University of Arizona is a synthetic analog of the naturally-occurring melanocortin peptide hormone alpha-melanocyte stimulating hormone that has been shown to induce skin pigmentation through melanogenesis and thereby subsequently reduce sun damage to UV exposed...
(formerly CUV1647) to provide photoprotection
Photoprotection
Photoprotection is a group of mechanisms that nature has developed to minimize the damage that the human body suffers when exposed to UV radiation...
for organ transplant patients against squamous cell carcinoma of the skin and actinic keratosis
Actinic keratosis
Actinic keratosis is a premalignant condition of thick, scaly, or crusty patches of skin. It is more common in fair-skinned people. It is associated with those who are frequently exposed to the sun, as it is usually accompanied by solar damage...
.