Login to Access Video or Poster Abstract: MP38-09
Sources of Funding: The Physicians Health Study was supported by the National Institutes of Health Grants No. CA-097193, CA-34944, CA-40360, HL-26490, and HL-34595. This work was also supported by the Dana-Farber Cancer Institute Mazzone Awards Program (M.A.P.), and the Prostate Cancer Foundation Young Investigator Award (L.A.M.); M.A.P. is an American Urological Association Urology Care Foundation Scholar._x000D_ Additional funding support provided from the National Cancer Institute Grants No. R33 CA127768-02, P50-CA92629, and P50-_x000D_ CA090381; Swedish Cancer Society Grant No. 3455; Fundaçion Federico; the Sidney Kimmel Center for Prostate and Urologic Cancers; David H. Koch through the Prostate Cancer Foundation; and a Cancer Center Support Grant from the National Cancer Institute made to Memorial Sloan Kettering Cancer Center Grant No. P30-CA008748 (S.C., and A.V.; PI: Craig B. Thompson).

Introduction

We sought to determine if a pre-diagnostic PSA level in men aged 60 to 70 predicts future risk of lethal prostate cancer and could be used to risk-stratify screening, potentially allowing men at low risk to be exempt from further screening.

Methods

We conducted a nested case-control study among men aged 60 (57.5-62.5), 65 (62.5-67.5) and 70 (67.5-72.5) years who gave blood before enrollment in the Physicians Health Study of primarily white, U.S. male physicians initiated in 1982. Baseline PSA levels were available for 109 lethal prostate cancer cases that were matched to 327 age-matched controls or non-lethal prostate cancer cases. Lethal was defined as metastatic (to bones or distant organs) or fatal prostate cancer. Conditional logistic regression was used to estimate odds ratios (ORs) with 95% confidence intervals (CIs), of the association between PSA and risk of lethal disease.

Results

Median PSA (ng/mL) among controls was 1.10 for men aged 60, 1.51 for men aged 65, and 1.52 for men aged 70. The 90th percentile of PSA levels among controls was 3.97 for men aged 60, 5.38 for men aged 65, and 5.17 for men aged 70. Median time from blood draw to lethal event among lethal cases was 15.3 years. Risk of lethal prostate cancer was strongly associated with baseline PSA levels: ORs (95% CIs) comparing PSA in the >90th percentile vs. ≤median were 7.5 (2.9, 19.1) for men aged 60, 19.3 (4.5, 82.0) for men aged 65, and 11.4 (3.0, 44.2) for men aged 70. 87% of lethal cases were in men with baseline PSA above the median.

Conclusions

Pre-diagnostic PSA level at age 60 to 70 strongly predicts future risk of lethal prostate cancer in a US cohort subject to opportunistic screening. This supports risk-stratified screening with consideration of exempting men with PSA below the median at age 60 onwards from further screening.

Funding

The Physicians Health Study was supported by the National Institutes of Health Grants No. CA-097193, CA-34944, CA-40360, HL-26490, and HL-34595. This work was also supported by the Dana-Farber Cancer Institute Mazzone Awards Program (M.A.P.), and the Prostate Cancer Foundation Young Investigator Award (L.A.M.); M.A.P. is an American Urological Association Urology Care Foundation Scholar._x000D_ Additional funding support provided from the National Cancer Institute Grants No. R33 CA127768-02, P50-CA92629, and P50-_x000D_ CA090381; Swedish Cancer Society Grant No. 3455; Fundaçion Federico; the Sidney Kimmel Center for Prostate and Urologic Cancers; David H. Koch through the Prostate Cancer Foundation; and a Cancer Center Support Grant from the National Cancer Institute made to Memorial Sloan Kettering Cancer Center Grant No. P30-CA008748 (S.C., and A.V.; PI: Craig B. Thompson).