The role of genetic screening and prophylactic surgery in surgical oncology.

Abstract

It is a fundamental principle that cancer is a genetic disease. Cancer results from the accumulation of genetic damage within the nucleus of a cell. Cancer is stably inherited during cell division so that when a cancer cell divides, both daughters are also cancer cells. Division of a progenitor cancer cell eventually results in transformation of an organ into a neoplastic phenotype. There is a large amount of evidence suggesting that in most patients cancer results from one or more acquired somatic mutations caused by chemical carcinogens or mutagens in the environment, but it is estimated that 1 of every 10 patients with breast, colon, and thyroid cancer inherits the disease by a germline mutation. Identifying the genetic mutation associated with a neoplasm can be useful to physicians in four ways: 1) to screen asymptomatic patients and possibly perform a prophylactic surgical procedure; 2) to tailor chemotherapy; 3) to suggest prognosis; and 4) to apply gene therapy. This is a collective review article, the purpose of which is to update surgeons on the current role of genetic screening for inherited breast, colon, and thyroid carcinoma in patients who already have cancer and in high-risk, asymptomatic individuals. It will also discuss indications and suggested methods of prophylactic surgery, tamoxifen chemoprevention, colonoscopy screening, and screening for associated malignancies. HISTORY OF MOLECULAR GENETICS