Patterns of cancer family history and genetic counseling eligibility among African Americans with breast, prostate, lung, and colorectal cancers: A Detroit Research on Cancer Survivors cohort study.

Background: Family history (FH) remains one of the strongest risk factors for many common cancers and is used to determine cancer genetic counseling (CGC) eligibility, but the understanding of familial cancer patterns in African Americans is limited.
Methods: This study evaluated cancer FH among African Americans with invasive breast cancer, prostate cancer, lung cancer, or colorectal cancer (CRC) in the Detroit Research on Cancer Survivors (ROCS) cohort. Associations between participant cancer type, site-specific FH, and meeting national guidelines for CGC were evaluated via logistic regression. Cancer FH patterns were evaluating via hierarchical clustering.
Results: Among 1500 ROCS participants, 71% reported at least 1 first-degree relative or grandparent with cancer. FHs of breast cancer, CRC, lung cancer, and prostate cancer were most common among participants with the same diagnosis (odds ratio [OR] for breast cancer, 1.14; P < .001; OR for CRC, 1.08; P = .003; OR for lung cancer, 1.09; P = .008; OR for prostate cancer, 1.14; P < .001). Nearly half of the participants (47%) met national CGC guidelines, and 24.4% of these participants met CGC criteria on the basis of their cancer FH alone. FH was particularly important in determining CGC eligibility for participants with prostate cancer versus breast cancer (OR for FH vs personal history alone, 2.91; 95% confidence interval, 1.94-4.35; P < .001). In clustering analyses, breast and prostate cancer FH-defined clusters were common across all participants. Clustering of CRC and breast cancer FHs was also observed.
Conclusions: ROCS participants reported high rates of cancer FH. The high rate of eligibility for CGC among ROCS participants supports the need for interventions to increase referrals and uptake of CGC among African Americans.
(© 2020 American Cancer Society.)