Ovarian cancer is the most fatal gynecological cancer in the United States. The most significant risk factor associated with developing this cancer is a familial history of the disease in one of two known syndromes, hereditary breast and ovarian cancer (HBOC) or hereditary nonpolyposis colorectal cancer (HNPCC). In cases of HBOC, two tumor suppressor genes, termed BRCA1 and BRCA2, get mutated. Thus a woman has a lifetime risk of developing ovarian cancer because damaged DNA is less likely to be repaired and there is less control on DNA replication fidelity. In women with BRCA1 mutations, there is a 40-65% increased chance of developing ovarian cancer and in BRCA2 patients, there is a 20% increased chance of developing the cancer, as compared to a 1.3% risk factor for the general population.[1] In addition, BRCA gene mutations increase a woman’s chance for breast cancer by 36-85%.[2] Luckily, genetic testing for both BRCA1 and BRCA2 is clinically available.
HNPCC, or Lynch II Syndrome, is associated with an increased risk of cancer in the colon, ovary, endometrium, stomach, small bowel, pancreas, bile ducts, and urinary tract. HNPCC increases a woman’s chance of developing ovarian cancer by 10%,[3] while also increasing the likelihood of developing colorectal cancer by 70%.[4] For women who are carriers for HNPCC, BRCA1, or BRCA 2, genetic testing, frequent cancer screenings, chemoprevention, and prophylactic surgery, or the removal of both ovaries and/or the fallopian tubes, are commonly used in order to reduce the risk. In fact, those procedures have been proven to be effective.
Environmental and reproductive factors can also play a role in developing ovarian cancer. For instance, an increased period of ovulation increases the risk of developing ovarian cancer because after ovulation, epithelial cells on the ovarian surface and fallopian tube encounter molecular insults (that may damage their DNA) as a result of ovulation per se. Therefore, there is a greater chance for mutations. In addition, nulliparity is also likely to increase a woman’s chance for developing the disease; woman who have been pregnant are 30-60% less likely to develop ovarian cancer.[5] Interestingly enough, however, the use of oral contraceptives can also help to reduce a woman’s risk of developing ovarian cancer if taken for more than 5 years. Some surgical methods, such as tubal ligation, in which the fallopian tubes are “tied”, or a hysterectomy in which the uterus is removed, can also decrease a woman’s risk of developing ovarian cancer, but the risks involved in surgery must be considered against the clinical benefit before such measures are taken. Not surprisingly, obesity also seems to be associated with a higher risk factor for developing ovarian cancer. Women are encouraged to regularly visit a doctor so that if ovarian cancer does develop, it can be detected early.
~ by Jessica Oldtman
(Johns Hopkins University)
[1] Armstrong, Deborah K. and Bristow, Robert E. Early Diagnosis and Treatment of Cancer: Ovarian Cancer. Philadelphia: Saunders Elsevier, 2010. Page 36-38.
[2] Armstrong, Deborah K. and Bristow, Robert E. Early Diagnosis and Treatment of Cancer: Ovarian Cancer. Philadelphia: Saunders Elsevier, 2010. Page 36.
[3] Armstrong, Deborah K. and Bristow, Robert E. Early Diagnosis and Treatment of Cancer: Ovarian Cancer. Philadelphia: Saunders Elsevier, 2010. Page 44.
[4] Bovicelli, Alessandro, Giordano, Antonio, and Kurman, Robert J. Molecular Pathology of Gynecological Cancer. Totowa, NJ: Humana Press Inc., 2007. Page 178.
[5] Armstrong, Deborah K. and Bristow, Robert E. Early Diagnosis and Treatment of Cancer: Ovarian Cancer. Philadelphia: Saunders Elsevier, 2010. Page 4.