Janet Lane-Claypon
Encyclopedia
Janet Elizabeth Lane-Claypon (1877–1967) was an English physician. She was one of the founders of the science of epidemiology
, pioneering the use of so-called cohort studies
and case-control studies.
Born into an affluent Lincolnshire
family, she was privately educated and entered the London School of Medicine for Women in 1898. A brilliant student, she won various honours, fellowships and degrees, including both an MD
and PhD
(making her an exceptionally early example of the "Doctor-doctor"
phenomenon only now becoming common in modern medicine). By 1910, Lane-Claypon had acquired student honors, distinctive fellowships, and a string of degrees, including a doctorate in physiology and an M.D. She first put these skills to work in the research lab, investigating the biochemistry of milk and aspects of reproductive physiology, including, importantly, the structure and function of the ovary and the hormonal control of lactation. In 1912, Lane-Claypon published a ground-breaking study of two cohort
s (groups) of babies, fed cow's milk and breast milk respectively. Lane-Claypon found that those babies fed breast milk gained more weight, and she used statistical methods to show that the difference was unlikely to occur by fluke alone. She also investigated whether something other than the type of milk could account for the difference, an effect known as confounding
. She moved from the lab to the arena of public health, where she grappled with a variety of maternal and child health issues. She became an advocate for breast feeding, as well as for the reform of midwife training and prenatal services, with a view to reducing the number of premature births and stillbirths and the rate of maternal mortality.
Having demonstrated the power of cohort studies, Lane-Claypon went on to develop another key type of epidemiological investigation, the so-called case-control study. In 1923, the Minister of Health, Neville Chamberlain
, set up a committee to look into the “causation, prevalence and treatment of cancer
” and to advise the ministry on the best way to investigate these problems. Lane-Claypon was hired to review the existing literature on breast cancer
with an emphasis on its surgical treatment (primarily radical mastectomies
). The committee then commissioned her to undertake a larger study “with a sufficient and suitable series” of women with breast cancer histories and “a parallel and equally representative series of control cases,” that is, “women whose conditions of life were broadly comparable to those of the cancer series but who had no sign of cancer”.
Lane-Claypon tracked down 500 women with a history of breast cancer
- the “cases” - and compared them with 500 women who were free of the disease but otherwise broadly similar, known as “controls”. No large-scale review of this kind had ever been undertaken. Lane-Claypon realized that to generate a sufficient number of cases and controls—500 in each category — she would need to enlist the support of several hospitals. Ultimately, six London and three Glasgow hospitals contributed data to the study, much of it apparently gathered under the supervision of other women physicians. Cases were defined as either recent or currently treated patients with breast cancer. Controls, women with no current or past histories of cancer, were drawn from inpatient and outpatient services of the hospitals supplying the cases. To demonstrate their comparability, Lane-Claypon evaluated both groups with respect to several variables, including occupation and infant mortality (both taken as proxies for social status), nationality, marital status, and age.
The detailed survey that emerged constituted, as far as we know, the first published epidemiological questionnaire. Among the more than 50 questions it asked were several relating to the respondents' reproductive health histories. This yielded results that enabled Lane-Claypon to identify many of the risk factors for breast cancer
that are still considered valid today. Her conclusions (or her data reworked by later researchers) agreed with those of modern reviewers: breast cancer was associated with age at menopause
, artificial menopause, age at first pregnancy
(age at marriage used as a proxy), number of children, and lactation
.
In 1926, the Ministry of Health published another of Lane-Claypon's report that is now considered the first “end results” study. It followed a large sample of women with pathologically confirmed breast cancer for up to 10 years after their surgery. The study confirmed that women who were surgically treated at an early stage of the disease had a much better chance of surviving three, five, or 10 years longer than those operated on at any later stage. She showed that breast cancer risk increased for childless women, women who married later than average, and women who did not breast feed. The overall breast cancer risk decreased according to the number of children. For all cases, rapid treatment held the key to survival among women with breast cancer. Woven through all of these reports are her concerns about the drawbacks and uncertainties that her own methodology exposed. Sidebar discussions reveal an extraordinarily rigorous and subtle intelligence at work. In the end-results study just mentioned, Lane-Claypon acknowledges the difficulties involved in deriving an accurate staging
of the disease (in the days before routine diagnostic
biopsies
). She understood that differences in access to health care (and hence to surgical treatment) would influence survival results. She recognized the problems of bias created by limiting the study to survivors and by relying on the recall of breast cancer patients themselves rather than observing (with greater neutrality and potentially greater accuracy) the experience of newly diagnosed women going through treatment and beyond. Finally, in reviewing the family histories of her cases, she anticipated the role that genes might play in the development of breast cancer. “There appear to be some families,” she wrote, “in which for reasons not certain at present, cancer plays havoc with the members, and there is (some) slight evidence in some instances that it attacks the same organs.”
Epidemiology
Epidemiology is the study of health-event, health-characteristic, or health-determinant patterns in a population. It is the cornerstone method of public health research, and helps inform policy decisions and evidence-based medicine by identifying risk factors for disease and targets for preventive...
, pioneering the use of so-called cohort studies
Cohort study
A cohort study or panel study is a form of longitudinal study used in medicine, social science, actuarial science, and ecology. It is an analysis of risk factors and follows a group of people who do not have the disease, and uses correlations to determine the absolute risk of subject contraction...
and case-control studies.
Born into an affluent Lincolnshire
Lincolnshire
Lincolnshire is a county in the east of England. It borders Norfolk to the south east, Cambridgeshire to the south, Rutland to the south west, Leicestershire and Nottinghamshire to the west, South Yorkshire to the north west, and the East Riding of Yorkshire to the north. It also borders...
family, she was privately educated and entered the London School of Medicine for Women in 1898. A brilliant student, she won various honours, fellowships and degrees, including both an MD
Doctor of Medicine
Doctor of Medicine is a doctoral degree for physicians. The degree is granted by medical schools...
and PhD
PHD
PHD may refer to:*Ph.D., a doctorate of philosophy*Ph.D. , a 1980s British group*PHD finger, a protein sequence*PHD Mountain Software, an outdoor clothing and equipment company*PhD Docbook renderer, an XML renderer...
(making her an exceptionally early example of the "Doctor-doctor"
Double degree
A double-degree program, sometimes called a combined degree, conjoint degree, dual degree, or simultaneous degree program, involves a student's working for two different university degrees in parallel, either at the same institution or at different institutions , completing them in less time than...
phenomenon only now becoming common in modern medicine). By 1910, Lane-Claypon had acquired student honors, distinctive fellowships, and a string of degrees, including a doctorate in physiology and an M.D. She first put these skills to work in the research lab, investigating the biochemistry of milk and aspects of reproductive physiology, including, importantly, the structure and function of the ovary and the hormonal control of lactation. In 1912, Lane-Claypon published a ground-breaking study of two cohort
Cohort (statistics)
In statistics and demography, a cohort is a group of subjects who have shared a particular time together during a particular time span . Cohorts may be tracked over extended periods in a cohort study. The cohort can be modified by censoring, i.e...
s (groups) of babies, fed cow's milk and breast milk respectively. Lane-Claypon found that those babies fed breast milk gained more weight, and she used statistical methods to show that the difference was unlikely to occur by fluke alone. She also investigated whether something other than the type of milk could account for the difference, an effect known as confounding
Confounding
In statistics, a confounding variable is an extraneous variable in a statistical model that correlates with both the dependent variable and the independent variable...
. She moved from the lab to the arena of public health, where she grappled with a variety of maternal and child health issues. She became an advocate for breast feeding, as well as for the reform of midwife training and prenatal services, with a view to reducing the number of premature births and stillbirths and the rate of maternal mortality.
Having demonstrated the power of cohort studies, Lane-Claypon went on to develop another key type of epidemiological investigation, the so-called case-control study. In 1923, the Minister of Health, Neville Chamberlain
Neville Chamberlain
Arthur Neville Chamberlain FRS was a British Conservative politician who served as Prime Minister of the United Kingdom from May 1937 to May 1940. Chamberlain is best known for his appeasement foreign policy, and in particular for his signing of the Munich Agreement in 1938, conceding the...
, set up a committee to look into the “causation, prevalence and treatment 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...
” and to advise the ministry on the best way to investigate these problems. Lane-Claypon was hired to review the existing literature on breast cancer
Breast cancer
Breast cancer is cancer originating from breast tissue, most commonly from the inner lining of milk ducts or the lobules that supply the ducts with milk. Cancers originating from ducts are known as ductal carcinomas; those originating from lobules are known as lobular carcinomas...
with an emphasis on its surgical treatment (primarily radical mastectomies
Radical mastectomy
Radical mastectomy is a surgical procedure in which the breast, underlying chest muscle , and lymph nodes of the axilla are removed as a treatment for breast cancer....
). The committee then commissioned her to undertake a larger study “with a sufficient and suitable series” of women with breast cancer histories and “a parallel and equally representative series of control cases,” that is, “women whose conditions of life were broadly comparable to those of the cancer series but who had no sign of cancer”.
Lane-Claypon tracked down 500 women with a history of breast cancer
Breast cancer
Breast cancer is cancer originating from breast tissue, most commonly from the inner lining of milk ducts or the lobules that supply the ducts with milk. Cancers originating from ducts are known as ductal carcinomas; those originating from lobules are known as lobular carcinomas...
- the “cases” - and compared them with 500 women who were free of the disease but otherwise broadly similar, known as “controls”. No large-scale review of this kind had ever been undertaken. Lane-Claypon realized that to generate a sufficient number of cases and controls—500 in each category — she would need to enlist the support of several hospitals. Ultimately, six London and three Glasgow hospitals contributed data to the study, much of it apparently gathered under the supervision of other women physicians. Cases were defined as either recent or currently treated patients with breast cancer. Controls, women with no current or past histories of cancer, were drawn from inpatient and outpatient services of the hospitals supplying the cases. To demonstrate their comparability, Lane-Claypon evaluated both groups with respect to several variables, including occupation and infant mortality (both taken as proxies for social status), nationality, marital status, and age.
The detailed survey that emerged constituted, as far as we know, the first published epidemiological questionnaire. Among the more than 50 questions it asked were several relating to the respondents' reproductive health histories. This yielded results that enabled Lane-Claypon to identify many of the risk factors for breast cancer
Breast cancer
Breast cancer is cancer originating from breast tissue, most commonly from the inner lining of milk ducts or the lobules that supply the ducts with milk. Cancers originating from ducts are known as ductal carcinomas; those originating from lobules are known as lobular carcinomas...
that are still considered valid today. Her conclusions (or her data reworked by later researchers) agreed with those of modern reviewers: breast cancer was associated with age at menopause
Menopause
Menopause is a term used to describe the permanent cessation of the primary functions of the human ovaries: the ripening and release of ova and the release of hormones that cause both the creation of the uterine lining and the subsequent shedding of the uterine lining...
, artificial menopause, age at first pregnancy
Pregnancy
Pregnancy refers to the fertilization and development of one or more offspring, known as a fetus or embryo, in a woman's uterus. In a pregnancy, there can be multiple gestations, as in the case of twins or triplets...
(age at marriage used as a proxy), number of children, and lactation
Lactation
Lactation describes the secretion of milk from the mammary glands and the period of time that a mother lactates to feed her young. The process occurs in all female mammals, however it predates mammals. In humans the process of feeding milk is called breastfeeding or nursing...
.
In 1926, the Ministry of Health published another of Lane-Claypon's report that is now considered the first “end results” study. It followed a large sample of women with pathologically confirmed breast cancer for up to 10 years after their surgery. The study confirmed that women who were surgically treated at an early stage of the disease had a much better chance of surviving three, five, or 10 years longer than those operated on at any later stage. She showed that breast cancer risk increased for childless women, women who married later than average, and women who did not breast feed. The overall breast cancer risk decreased according to the number of children. For all cases, rapid treatment held the key to survival among women with breast cancer. Woven through all of these reports are her concerns about the drawbacks and uncertainties that her own methodology exposed. Sidebar discussions reveal an extraordinarily rigorous and subtle intelligence at work. In the end-results study just mentioned, Lane-Claypon acknowledges the difficulties involved in deriving an accurate staging
Cancer staging
The stage of a cancer is a description of the extent the cancer has spread. The stage often takes into account the size of a tumor, how deeply it has penetrated, whether it has invaded adjacent organs, how many lymph nodes it has metastasized to , and whether it has spread to distant organs...
of the disease (in the days before routine diagnostic
Diagnosis
Diagnosis is the identification of the nature and cause of anything. Diagnosis is used in many different disciplines with variations in the use of logics, analytics, and experience to determine the cause and effect relationships...
biopsies
Biopsy
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...
). She understood that differences in access to health care (and hence to surgical treatment) would influence survival results. She recognized the problems of bias created by limiting the study to survivors and by relying on the recall of breast cancer patients themselves rather than observing (with greater neutrality and potentially greater accuracy) the experience of newly diagnosed women going through treatment and beyond. Finally, in reviewing the family histories of her cases, she anticipated the role that genes might play in the development of breast cancer. “There appear to be some families,” she wrote, “in which for reasons not certain at present, cancer plays havoc with the members, and there is (some) slight evidence in some instances that it attacks the same organs.”
External links
- "Vignettes of the history of epidemiology: Three firsts by Janet Elizabeth Lane-Claypon" by Warren Winkelstein American Journal of Epidemiology 2004 July 15;160(2), pgs. 97–101
- Unsung Heroines: Unveiling History Janet Elizabeth Lane-Claypon by Ellen Leopold and Warren Winkelstein Jr. BCA Newsletter #81–May/June 2004