According to the Centers for Disease Control and Prevention (CDC), each year, approximately 20,000 women in the United States are diagnosed with ovarian cancer. Among women in the US, ovarian cancer is the eighth most common cancer and the fifth leading cause of cancer death, after lung, breast, colorectal, and pancreatic cancers. Ovarian cancer causes more deaths than any other cancer of the female reproductive system; however, it accounts for only about 3% of all cancers in women. Despite those grim statistics, a new study reports that long-term survival is not uncommon. The findings were published in the September edition of the journal Obstetrics & Gynecology by researchers at University of California, Davis.
The study authors note that both patients and physicians commonly perceive ovarian cancer as a highly fatal disease, and that is because most patients present with advanced-stage disease, the prognosis is often poor. Ovarian cancer 5-year survival varies significantly by stage but, for women diagnosed in 2004–2010, ranged from 92% for localized disease to 27% for metastatic disease.
Most women diagnosed with advanced-stage ovarian cancer will die of the disease; however, the biological behavior of ovarian cancer is extremely variable. Even some of those patients with high-risk, advanced-stage ovarian cancer survive well beyond 5 years. The authors note that data regarding long-term survival from ovarian cancer survivor because very studies extend beyond 5 years of survival. Therefore, the purpose of the study was to identify characteristics associated with long-term survival from epithelial ovarian cancer using the California Cancer Registry.
The researchers analyzed the survival of all California residents diagnosed with epithelial ovarian cancer from 1994 through 2001; the patients were identified through the cancer registry with follow-up through 2011. Characteristics of the patients who survived more than 10 years (long-term survivors) were compared to three other groups: patients who survived less than 2 years, those who survived at least 2 but no more than 5 years, and those who survived at least 5 but no more than 10 years.
The investigators found that 3,582 of 11,541 (31%) patients survived more than 10 years. Younger age, early stage, low-grade, and nonserous histology (an ovarian cancer not of a serous type) were significant predictors of long-term survival; however, long-term survivors also included women with high-risk cancer.
The authors concluded that long-term survival is not unusual in patients with epithelial ovarian cancer, even in women with high-risk disease. Many of the predictive factors are well known; however, it remains to be determined why some patients with advanced-stage high-grade cancers survive longer than others with the same tissue diagnosis. Thus, these findings are important for patient counseling.