Extended mortality results for ovarian cancer screening in the PLCO trial with median 15 years follow-up

Background. The Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial originally reported no mortality benefit of ovarian cancer screening after a median of 12.4 years of follow-up. The UKCTOCS screening trial failed to show a statistically significant mortality reduction in the primary analysis but reported an apparent increased mortality benefit in trial years 7-14 compared to 0-7. Here we report an updated analysis of PLCO with extended mortality follow-up. Methods. Participants were randomized from 1993 to 2001 at ten U.S. centers to an intervention or usual care arm. Intervention arm women were screened for ovarian cancer with annual trans-vaginal ultrasound (TVU) (4 years) and CA-125 (6 years), with a fixed cutoff at 35 U/mL for CA-125. The original follow-up period was for up to 13 years (median follow-up 12.4 years); in this analysis follow-up for mortality was extended by up to 6 years. Results. 39,105 (intervention) and 39,111 (usual care) women were randomized, of which 34,253 and 34,304, respectively, had at least one ovary at baseline. Median follow-up was 14.7 years in each arm and maximum follow-up 19.2 years in each arm. A total of 187 (intervention) and 176 (usual care) deaths from ovarian cancer were observed, for a risk-ratio of 1.06 (95% Cl: 0.87-1.30). Risk-ratios were similar for study years 0-7 (RR = 1.04), 7-14 (RR = 1.06) and 14+ (RR = 1.09). The risk ratio for all-cause mortality was 1.01 (95% CI: 0.97-1.05). Ovarian cancer specific survival was not significantly different across trial arms (p = 0.16). Conclusion. Extended follow-up of PLCO indicated no mortality benefit from screening for ovarian cancer with CA-125 and TVU. Published by Elsevier Inc.