Extended mortality results for ovarian cancer screening in the PLCO trial with median 15years 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 12.4years 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).


CONCLUSIONS
Extended follow-up of PLCO indicated no mortality benefit from screening for ovarian cancer with CA-125 and TVU.
Division of Cancer Prevention, National Cancer Institute, National Institutes of Health, United States. Electronic address: pp4f@nih.gov.
Paul F
PF
Pinsky
Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, United States.
Kelly
K
Yu
Division of Cancer Prevention, National Cancer Institute, National Institutes of Health, United States.
Barnett S
BS
Kramer
Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, United States.
Amanda
A
Black
University of Utah School of Medicine, United States.
Saundra S
SS
Buys
University of Alabama at Birmingham School of Medicine, United States.
Edward
E
Partridge
Office of Disease Prevention, National Institutes of Health, United States.
John
J
Gohagan
Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, United States.
Christine D
CD
Berg
Division of Cancer Prevention, National Cancer Institute, National Institutes of Health, United States.
Philip C
PC
Prorok
D000368:Aged; D018394:CA-125 Antigen / Q000097:blood*; D055088:Early Detection of Cancer; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged; D010051:Ovarian Neoplasms / Q000175:diagnosis / Q000401:mortality*; D014463:Ultrasonography; D014621:Vagina / Q000000981:diagnostic imaging
D018394:CA-125 Antigen