Family History of Prostate Cancer and Survival Outcomes in the UK Genetic Prostate Cancer Study

Background: A family history (FH) of prostate cancer (PrCa) is associated with an increased likelihood of PrCa diagnosis. Conflicting evidence exists regarding familial PrCa and clinical outcomes among PrCa patients, including all-cause mortality/overall survival (OS), PrCa-specific survival (PCSS), aggressive histology, and stage at diagnosis. Objective: To determine how the number, degree, and age of a PrCa patient's affected rel-atives are associated with OS and PCSS of those already diagnosed with PrCa. Design, setting, and participants: The UK Genetic Prostate Cancer Study is a longitudinal, multi-institutional, observational study collecting baseline and follow-up clinical data since 1992. We examined OS and PCSS in 16 340 men by degree and number of relatives with prostate and genetically related cancers (breast, ovarian, and colorectal). Outcome measurements and statistical analysis: The primary outcome was all-cause mortality among PrCa patients. The risk of death with respect to FH was assessed by cal-culating hazard ratios from Cox proportional hazard regression models, adjusting for rel-evant factors. Results and limitations: A stronger FH was inversely associated with the risk of all-cause and PrCa-specific mortality. This association was greater in those with an increasing number (p-trend < 0.001) and increasing closeness (p-trend < 0.001) of the diagnosed relatives. Patients with at least one first-degree relative were at a lower risk of all -cause mortality than those with no FH (hazard ratio = 0.82 [95% confidence interval 0.75-0.89]). The population is largely of European ancestry, and this may cause an issue with representation and generalisation. Data are missing on epidemiological risk factors for death such as smoking and on comorbidities. Recall of family members' diagnoses may affect the classification of FH in unconfirmed cases. Conclusions: Based on the investigation of the type and timing of relatives' cancers, it is likely that reductions in mortality are due almost completely to a greater awareness of