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

Gynecol Oncol. 2016 Nov;143(2):270-275. doi: 10.1016/j.ygyno.2016.08.334. Epub 2016 Sep 9.


Background: The Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial originally reported no mortality benefit of ovarian cancer screening after a median of 12.4years 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) (4years) and CA-125 (6years), with a fixed cutoff at 35U/mL for CA-125. The original follow-up period was for up to 13years (median follow-up 12.4years); in this analysis follow-up for mortality was extended by up to 6years.

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 14.7years in each arm and maximum follow-up 19.2years 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% CI: 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.

Publication types

  • Multicenter Study
  • Randomized Controlled Trial

MeSH terms

  • Aged
  • CA-125 Antigen / blood*
  • Early Detection of Cancer*
  • Female
  • Follow-Up Studies
  • Humans
  • Middle Aged
  • Ovarian Neoplasms / diagnosis
  • Ovarian Neoplasms / mortality*
  • Ultrasonography
  • Vagina / diagnostic imaging


  • CA-125 Antigen