Abstract 1182: Association of prostate cancer candidate genes with overall and aggressive prostate cancer in men of African ancestry

Abstract Background: There is a growing body of evidence supporting the contributions of germline rare variants to the susceptibility of prostate cancer (PCa), especially aggressive PCa. Our previous exome sequencing analysis highlighted 36 aggressive PCa candidate genes in populations of European ancestry. Here we investigated whether rare germline pathogenic, likely pathogenic, or deleterious (P/LD/D) variants in these genes were associated with overall and aggressive PCa risk in men of African ancestry. Methods: This exome sequencing analysis consists of 7,176 prostate cancer cases and 4,873 controls from the Research on Prostate Cancer in Men of African Ancestry (RESPOND) study. Among the PCa cases, 3,283 are aggressive cases (tumor stage T3/T4, regional lymph node involvement, metastatic disease, Gleason score >= 8.0, prostate-specific antigen [PSA] level >= 20 ng/mL or PCa as the underlying cause of death) including 1,074 metastatic cases, and 1,752 are non-aggressive cases (Gleason score ⇐ 7.0, PSA < 20 ng/mL, and tumor stage T1/T2). P/LP/D variants analyzed were rare (minor allele frequency < 1% in controls) and had either a Variant Effect Predictor impact score of “high” or a pathogenic or likely pathogenic ClinVar classification. The association between P/LP/D carrier status with risk of overall PCa, aggressive PCa, and metastatic PCa was evaluated in logistic regression models, adjusting for age and the top ten principal components. All statistical tests are two-sided. Results: Of the 36 PCa candidate genes, BRCA2 was the most frequently affected gene, with 1.7% of cases and 1.1% of controls harboring a germline P/LP/D variant, followed by MUTYH (1.5%/1.3%) ATM (0.93%/0.49%), MSH5 (0.70%/0.51%) and HOXB13 (0.70%/0.35%). Nominally significant associations with overall PCa were observed for ATM (OR=1.83, 95% CI=1.14-2.92, P=0.012), BRCA2 (OR=1.52, 95% CI=1.10-2.10, P=0.011), HOXB13 (OR=2.10, 95% CI=1.12-3.66, P=0.008), and PALB2 (OR=3.46, 95% CI=1.18-10.1, P=0.02). In case-case analyses (aggressive vs. non-aggressive cases), the association with aggressive PCa was nominally significant for ATM (OR=5.10, 95% CI=1.96-13.3, P=8.7 × 10−4) and BRCA2 (OR=2.00, 95% CI=1.19-3.38, P=0.009) and was suggestive for PALB2 (OR=2.99, 95% CI=0.83-10.7, P=0.09). Similar associations with metastatic PCa were also observed for these three genes. Conclusion: The associations of BRCA2, ATM, and PALB2 with overall PCa and aggressive PCa observed in men of African ancestry are consistent with findings from our previous study in men of European ancestry. These findings further support the importance of these genes in the consideration of screening and active surveillance for high-risk and advanced disease. Citation Format: Fei Chen, Burcu F. Darst, Xin Sheng, Anqi Wang, Yili Xu, Raymond Hughley, Ben Adusei, Mohamed Jalloh, Serigne Magueye Gueye, Andrew A. Adjei, James Mensah, Pedro W. Fernandez, Akindele O. Adebiyi, Oseremen Aisuodionoe-Shadrach, Lindsay Petersen, Maureen Joffe, Jo McBride, Jeannette T. Bensen, James L. Mohler, Jack A. Taylor, Eboneé N. Butler, Sue A. Ingles, Benjamin A. Rybicki, Janet L. Stanford, Wei Zheng, Sonja I. Berndt, Chad D. Huff, Joseph Lachance, Luc Multigner, Caroline Andrews, Timothy R. Rebbeck, Laurent Brureau, Stephen J. Chanock, David V. Conti, Christopher A. Haiman. Association of prostate cancer candidate genes with overall and aggressive prostate cancer in men of African ancestry [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1182.