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The oral microbiome, like the fecal microbiome, may be related to breast cancer risk. Therefore, we investigated whether the oral microbiome was associated with breast cancer and nonmalignant breast disease, and its relationship with the fecal microbiome in a case-control study in Ghana. A total of 881 women were included (369 breast cancers, 93 nonmalignant cases and 419 population-based controls). The V4 region of the 16S rRNA gene was sequenced from oral and fecal samples. Alpha-diversity (observed amplicon sequence variants [ASVs], Shannon index and Faith's Phylogenetic Diversity) and beta-diversity (Bray-Curtis, Jaccard and weighted and unweighted UniFrac) metrics were computed. MiRKAT and logistic regression models were used to investigate the case-control associations. Oral sample alpha-diversity was inversely associated with breast cancer and nonmalignant breast disease with odds ratios (95% CIs) per every 10 observed ASVs of 0.86 (0.83-0.89) and 0.79 (0.73-0.85), respectively, compared to controls. Beta-diversity was also associated with breast cancer and nonmalignant breast disease compared to controls (P ≤ .001). The relative abundances of Porphyromonas and Fusobacterium were lower for breast cancer cases compared to controls. Alpha-diversity and presence/relative abundance of specific genera from the oral and fecal microbiome were strongly correlated among breast cancer cases, but weakly correlated among controls. Particularly, the relative abundance of oral Porphyromonas was strongly, inversely correlated with fecal Bacteroides among breast cancer cases (r = -.37, P ≤ .001). Many oral microbial metrics were strongly associated with breast cancer and nonmalignant breast disease, and strongly correlated with fecal microbiome among breast cancer cases, but not controls.

Background: Risk estimates for women carrying germline mutations in breast cancer susceptibility genes are mainly based on studies of European ancestry women. Methods: We investigated associations between pathogenic variants (PV) in 34 genes with breast cancer risk in 871 cases [307 estrogen receptor (ER)-positive, 321 ER-negative, and 243 ER-unknown] and 1,563 controls in the Ghana Breast Health Study (GBHS), and estimated lifetime risk for carriers. We compared results with those for European, Asian, and African American ancestry women. Results: The frequency of PV in GBHS for nine breast cancer genes was 8.38% in cases and 1.22% in controls. Relative risk estimates for overall breast cancer were: (OR, 13.70; 95% confidence interval (CI), 4.03–46.51) for BRCA1, (OR, 7.02; 95% CI, 3.17–15.54) for BRCA2, (OR, 17.25; 95% CI, 2.15–138.13) for PALB2, 5 cases and no controls carried TP53 PVs, and 2.10, (0.72–6.14) for moderate-risk genes combined (ATM, BARD1, CHEK2, RAD51C, RAD52D). These estimates were similar to those previously reported in other populations and were modified by ER status. No other genes evaluated had mutations associated at P < 0.05 with overall risk. The estimated lifetime risks for mutation carriers in BRCA1, BRCA2, and PALB2 and moderate-risk genes were 18.4%, 9.8%, 22.4%, and 3.1%, respectively, markedly lower than in Western populations with higher baseline risks. Conclusions: We confirmed associations between PV and breast cancer risk in Ghanaian women and provide absolute risk estimates that could inform counseling in Ghana and other West African countries. Impact: These findings have direct relevance for breast cancer genetic counseling for women in West Africa.

Background Pediatric cancers are the leading cause of death by disease in children despite improved survival rates overall. The contribution of germline genetic susceptibility to pediatric cancer survivors has not been extensively characterized. We assessed the frequency of pathogenic or likely pathogenic (P/LP) variants in 5451 long-term pediatric cancer survivors from the Childhood Cancer Survivor Study. Methods Exome sequencing was conducted on germline DNA from 5451 pediatric cancer survivors (cases who survived ≥5 years from diagnosis; n = 5105 European) and 597 European cancer-free adults (controls). Analyses focused on comparing the frequency of rare P/LP variants in 237 cancer-susceptibility genes and a subset of 60 autosomal dominant high-to-moderate penetrance genes, for both case-case and case-control comparisons. Results Of European cases, 4.1% harbored a P/LP variant in high-to-moderate penetrance autosomal dominant genes compared with 1.3% in controls (2-sided P = 3 × 10-4). The highest frequency of P/LP variants was in genes typically associated with adult onset rather than pediatric cancers, including BRCA1/2, FH, PALB2, PMS2, and CDKN2A. A statistically significant excess of P/LP variants, after correction for multiple tests, was detected in patients with central nervous system cancers (NF1, SUFU, TSC1, PTCH2), Wilms tumor (WT1, REST), non-Hodgkin lymphoma (PMS2), and soft tissue sarcomas (SDHB, DICER1, TP53, ERCC4, FGFR3) compared with other pediatric cancers. Conclusion In long-term pediatric cancer survivors, we identified P/LP variants in cancer-susceptibility genes not previously associated with pediatric cancer as well as confirmed known associations. Further characterization of variants in these genes in pediatric cancer will be important to provide optimal genetic counseling for patients and their families.