In the United States, ovarian cancer accounts for more deaths than any other gynecologic malignancy. Worldwide each year, more than 295,000 women are diagnosed, and 185,000 women die from this disease (Bray, 2018). Of these, epithelial ovarian carcinomas make up 90 percent of all cases, including the more indolent low-malignant-potential (borderline) tumors (Torre, 2018). The remainder includes germ cell and sex cord–stromal tumors, which are described in Chapter 36 (p. 756). Due to the similarities of primary peritoneal carcinomas and fallopian tube cancers, they are included within this section for simplicity.
Approximately one quarter of patients will have stage I disease and an excellent long-term survival rate. However, no test effectively screens for ovarian cancer, and early symptoms are few. As a result, two thirds of patients have advanced disease when diagnosed. Debulking surgery sequenced with platinum-based chemotherapy usually results in clinical remission. However, up to 90 percent of these women will develop a relapse that eventually leads to disease progression and death.
EPIDEMIOLOGY AND RISK FACTORS
In the United States, 1 in 78 women (1.3 percent) will develop ovarian cancer during her lifetime (Torre, 2018). Because the incidence has declined by 30 percent during the past three decades, ovarian cancer no longer resides among the top ten leading causes of cancer in women. In 2019, 22,530 new cases and 13,980 deaths are expected. Yet due to the high rate of mortality, ovarian cancer remains the fifth leading cause of cancer-related death (Siegel, 2019). Overall, the average age at diagnosis is in the early 60s.
Numerous reproductive, environmental, and genetic risk factors have been associated with ovarian cancer (Table 35-1) (Armstrong, 2019). The most important is a family history of breast or ovarian cancer, and up to 25 percent of patients have an inherited genetic predisposition (American College of Obstetricians and Gynecologists, 2017a). For the other 75 percent with no identifiable genetic link for their ovarian cancer, risks have traditionally been attributed to a pattern of uninterrupted ovulatory cycles during the reproductive years (Pelucchi, 2007). Repeated stimulation of the ovarian surface epithelium is hypothesized to lead to malignant transformation (Schildkraut, 1997).
TABLE 35-1Risk Factors for Developing Epithelial Ovarian Cancer ||Download (.pdf) TABLE 35-1 Risk Factors for Developing Epithelial Ovarian Cancer
Residence in North America and Northern Europe
Personal history of breast cancer
Ethnic background (European Jewish, Icelandic, Hungarian)
Postmenopausal hormone therapy
Pelvic inflammatory disease
Nulliparity is associated with long periods of repetitive ovulation, and patients without children have double the risk of developing ovarian cancer (Purdie, 2003). Among nulliparas, those with a history of infertility ...