In 2014, it is estimated that 21,980 new cases of ovarian cancer will be diagnosed and 14,270 deaths due to ovarian cancer will occur. Incidence and mortality rates are higher among whites than blacks, but statistically significant decreases in incidence and mortality rates have been observed among both whites and blacks. A statistically significant decrease in delayed adjusted incidence of 0.9% among whites from 1987 to 2010 and 0.4% among blacks from 1997 to 2010 has been observed. A statistically significant decrease in mortality rates of 1.9% per year among whites from 2002 to 2010 and 0.9% per year among blacks from 1992 to 2010 has been observed. The population lifetime risk of ovarian cancer is 1.37%; the population lifetime risk of dying from ovarian cancer is 0.99%.
Flanking the uterus are the two ovaries, each about the size of an almond, which produce eggs and female hormones. Ovarian cancer can occur at any age, even in childhood, but is most common after menopause. The disease accounts for about 22,000 new cases and almost 15,000 deaths annually in the U.S.
During her childbearing years, a woman's ovaries deliver eggs to the uterus through the fallopian tubes. The ovaries are susceptible to several types of growths, which are often benign cysts,...
Underlying ovarian cancer risk can be assessed through accurate pedigrees and/or genetic markers of risk. Because of uncertainties about cancer risks associated with specific gene mutations, genetic information may be difficult to interpret outside of families with a high incidence of ovarian cancer. The following three inherited ovarian cancer susceptibility syndromes have been described: (1) familial site-specific ovarian cancer; (2) familial breast/ovarian cancer; and (3) Lynch II syndrome, which is a combination of breast, ovarian, endometrial, gastrointestinal, and genitourinary cancers.[3,4] Considering family history in the absence of specific information on BRCA1/2 mutation status, unaffected women who have two or three relatives with ovarian cancer have a cumulative ovarian cancer risk of about 7%.[3,5] Women who have a mother or sister with ovarian cancer have a cumulative lifetime risk of ovarian cancer of about 5%.
Histology and Pathogenesis of Ovarian Cancer
Ovarian cancer may be of germ cell, stromal, or epithelial origin. Epithelial ovarian cancer, the most common type, is the focus of this summary. The term epithelial ovarian cancer encompasses a heterogeneous group of tumors. Classically, ovarian tumors have been classified as serous, mucinous, endometrioid, and clear cell. However, a dual classification system of type I and type II tumors has been proposed that incorporates molecular profiling of tumors as well as histology and clinical behavior. Type I tumors usually present at a low stage, are associated with an excellent clinical prognosis, and encompass borderline malignant tumors. Type II tumors are more aggressive, usually present in an advanced stage, and have a variety of histologies. Type I tumors tend to be more stable genetically than type II tumors, with type II tumors also having a high prevalence of TP53 mutations. About 75% of epithelial cancers are type II tumors and include ovarian cancer such as serous, endometrioid, and mixed mesodermal tumors. There is increasing evidence that the two types of cancers are different genetically, and thus, may have different molecular pathways of development. Evidence also suggests that both of these types develop outside the ovary and then secondarily involve the ovary, with most type II tumors being of tubal origin. This is hypothesized to be the case for both genetic cancers (BRCA1/2-mutation associated cancers) and most noninherited forms of ovarian cancer.