Familial clustering of prostate cancer (Pca) cases in a nonselected south European population (sEp).

Abstract

233 Background: Universal Pca screening programs (SP) are controversial. The selection of high-risk subjects might improve the efficiency of early SP. A positive family history (FH) of Pca increases its relative risk and also increases with multiple affected relatives. Pca FH is associated with earlier onset and aggressive behavior. Therefore, in this subpopulation SP would have clear advantages. This is the first study to investigate the incidence of familial Pca conducted in a sEp. Methods: Overall, 365 cancer patients (pts) of Spanish (n=342) or Portuguese (n=23) origin diagnosed at a single institution were included in the analysis. A non-selected cohort of 182 (173 with known FH) consecutive males (cases) diagnosed with Pca was studied for FH of any type of cancer including Pca. Another cohort of 183 (174 with known FH) males (controls) with similar demographic characteristics and diagnosed with other cancer types different from Pca was also studied for FH of cancer. We investigated whether Pca pts in a sEp show a higher incidence of familial Pca aggregation than subjects affected by other solid tumors. Results: Among Pca pts with a positive FH for Pca, 30.2% showed their father as the only Pca relative, 22.6% one or more brothers, 15% one or more uncles, 13.3% their father and one or more brothers, 9.4% their grandfather and 9.5% showed other combinations. Regarding the number of relatives affected, in our Pca cohort 1 relative was the most frequent finding with 41/53 pts (77.1%), 2 in 4 cases (7.6%), 3 in 3 subjects (5.8%) and 4 or more relatives in 5 cases (9.5%). We studied the overall incidence of any type of family cancer among cases and controls. No differences were found between groups (64.7% vs 67.8%; p=0.664). However, in our cohort of Pca cases, 53/173 pts (30.6%) had a FH of Pca in first or second degree whereas, among cancer control pts only 18/174 pts (10.34%) showed a Pca FH (p=0.001). Conclusions: We present the first estimation of Pca FH in a non-selected sEp with Pca. 30% of Pca cases showed a positive FH for Pca, being that incidence significantly higher (threefold) compared to cancer pts from a different origin. Therefore, the usefulness of directed SP for subjects with positive FH of Pca should be prospectively evaluated.