Prostate Cancer Incidence and Mortality in Relationship to Family History of Prostate Cancer; Findings From The PLCO Trial

Family history of prostate cancer is associated with an increased risk of prostate cancer diagnosis in the overall cohort of patients as well as a higher risk of prostate cancer mortality in the nonscreened subcohort. Further prospective assessment of the role of screening among selected high-risk populations (including those with strong family history) is warranted. Background: The purpose of the study was to determine the relationship between family history of prostate cancer in a first-degree relative (FDR) and prostate cancer incidence and mortality. Patients and Methods: Deidentified data sets of men recruited in the Prostate, Lung, Colorectal, and Ovary (PLCO) trial were accessed. Men with complete information about family history of prostate cancer in an FDR were included. The effect of family history on prostate cancer incidence and mortality was assessed in a multivariate Cox regression model. Likewise, the effect of the number of FDRs with prostate cancer and the effect of youngest diagnosis age of an FDR with prostate cancer were assessed. Results: A total of 74,781 participants were included in the current analysis, including 5281 participants with family history of prostate cancer in an FDR and 69,500 participants without family history of prostate cancer in an FDR. Among participants without family history of prostate cancer in an FDR, a total of 7450 patients (10.5%) were subsequently diagnosed with prostate cancer; whereas among patients with family history of prostate cancer in an FDR, a total of 889 patients (16.5%) were subsequently diagnosed with prostate cancer. In an adjusted multivariate Cox regression model, family history of prostate cancer was associated with a higher probability of prostate cancer diagnosis (hazard ratio [HR], 1.590; 95% confidence interval [CI], 1.482-1.705; P .001). The number of FDRs with prostate cancer proportionally correlated with higher prostate cancer incidence (HR, 1.529; 95% confidence interval [CI], 1.439-1.624; P < .001). Family history of prostate cancer in an FDR was not predictive of higher prostate cancer mortality in the PLCO screening (intervention) arm (HR, 0.829; 95% CI, 0.422-1.629; P = .587) whereas it was predictive of a higher prostate cancer mortality in the PLCO nonscreening (control) arm (HR, 1.894; 95% CI, 1.154-3.109; P = .012). Number of FDRs with prostate cancer was not associated with higher prostate cancer mortality in the PLCO screening (intervention) arm (HR, 0.956; 95% CI, 0.541-1.691; P = .878), whereas it was associated with higher prostate cancer mortality in the PLCO nonscreening (control) arm (HR, 1.643; 95% CI, 1.083-2.493; P = .020). Conclusion: Family history of prostate cancer is associated with an increased risk of prostate cancer diagnosis in the overall cohort of patients as well as a higher risk of prostate cancer mortality in the nonscreened subcohort. Further prospective assessment of the role of screening among selected high-risk populations (including those with strong family history) is warranted. (C) 2019 Elsevier Inc. All rights reserved.