In the United States, ovarian cancer is among the 5 leading causes of cancer death in women. The high case-fatality ratio of ovarian cancer may be attributed in part to its vague and nonspecific symptoms, which usually appear when the disease has reached an advanced stage. Ovarian cancer confined to the ovary has a 5-year survival of 92%. However, most women with ovarian cancer are diagnosed with advanced stage disease, which has a 5-year survival of only 30%.
The disappointing results from a very large study (almost 80,000 women) from the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial is that there was no reduction in mortality from ovarian cancer in women who were screened with six annual blood CA-125 tests and four annual trans-vaginal ultrasounds. There were also no stage-shifts (detection of cancer at an earlier stage). This suggests that CA-125 and trans-vaginal ultrasounds are not the correct tests for early detection. Evidence from modeling suggests that aggressive cancers progress rapidly through the early stages, limiting the ability to detect these cancers with yearly screening.
Similar studies are ongoing in the United Kingdom and in Japan. The authors of this article conclude that in the U.S., the screening strategy used in the PLCO trial "does not reduce disease-specific mortality in women at average risk for ovarian cancer but does increase invasive medical procedures and associated harms."
Published early on line: June 4, 2011. doi:10.1001/jama.2011.766
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