Debulking is the surgical

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...

 removal of part of a malignant

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...

 tumour which cannot be completely excised, so as to enhance the effectiveness of radiation or chemotherapy

Chemotherapy

Chemotherapy is the treatment of cancer with an antineoplastic drug or with a combination of such drugs into a standardized treatment regimen....

. It is used only in specific malignancies, as generally partial removal of a tumor is not considered a worthwhile intervention. Ovarian carcinoma and some types of brain tumor

Brain tumor

A brain tumor is an intracranial solid neoplasm, a tumor within the brain or the central spinal canal.Brain tumors include all tumors inside the cranium or in the central spinal canal...

are debulked prior to commencing radio- or chemotherapy. It may also be used in the case of slow growth tumors to shift tumor cells from phase of cell cycle to replicative pool.

It is usually a long and often complicated procedure taking several hours or more to perform, depending on internal involvement and location.

Debulking is also known as cytoreduction surgery; "cytoreduction" refers to reducing the number of cancer cells.