Effect of screening on ovarian cancer mortality in the Prostate, Lung, Colorectal, and Ovarian (PLCO) cancer randomized screening trial.

Abstract

5001 Background: Ovarian cancer is among the five leading causes of cancer death in women in the United States. Women diagnosed with early stage disease have significantly improved survival compared to women diagnosed with advanced ovarian cancer. However, the effect on mortality of screening for the early detection of ovarian cancer with CA-125 and transvaginal ultrasound (TVU) is unknown. We evaluated the effect on mortality of screening for ovarian cancer in the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial. Methods: PLCO is a randomized controlled trial involving 10 screening centers across the U.S. that recruited 78,216 women aged 55-74 years. Women were randomized to receive either annual screening(intervention arm; 39,105 participants) or usual care (39,111 participants) between November 1993 and July 2001. Women in the intervention arm were offered annual CA-125 testing for6 years and TVU for 4 years. Participants and their health care providers received the screening test results and managed evaluation of abnormal results. All participants were followed for up to 13 years for cancer diagnoses and death. The primary outcome was ovarian cancer mortality. Secondary outcomes included ovarian cancer incidence and complications associated with screening exams and diagnostic procedures. Results: Ovarian cancer was diagnosed in 212 women in the intervention arm and 176 in the usual care arm, for a rate ratio of 1.21 (95% Confidence Interval (CI) 0.99 – 1.48). There were 118 deaths from ovarian cancer in the intervention arm and 100 in the usual care arm, for a mortality rate ratio of 1.18 (95% CI 0.91-1.54). Of 3,285 women undergoing surgery following a false positive exam, 166 encountered at least one serious complication. Deaths from all other causes (excluding ovarian, colorectal and lung cancer) were 2,924 and 2,914 in the intervention and usual care arms, respectively. Conclusions: Screening simultaneously with CA-125 and TVU did not reduce ovarian cancer mortality in women from the general population, and there was evidence of harm from diagnostic evaluation following a false positive screening test.