RESUMEN
Less than 15-20% of patients who meet the criteria for hereditary breast and ovarian cancer (HBOC) carry pathogenic coding genetic mutations, implying that other molecular mechanisms may contribute to the increased risk of this condition. DNA methylation in peripheral blood has been suggested as a potential epigenetic marker for the risk of breast cancer (BC). We aimed to discover methylation marks in peripheral blood associated with BC in 231 pre-treatment BC patients meeting HBOC criteria, testing negative for coding pathogenic variants, and 156 healthy controls, through methylation analysis by targeted bisulfite sequencing on 18 tumor suppressor gene promoters (330 CpG sites). We found i) hypermethylation in EPCAM (17 CpG sites; p = 0.017) and RAD51C (27 CpG sites; p = 0.048); ii) hypermethylation in 36 CpG-specific sites (FDR q < 0.05) in the BC patients; iii) four specific CpG sites were associated with a higher risk of BC (FDR q < 0.01, Bonferroni p < 0.001): cg89786999-FANCI (OR = 1.65; 95% CI:1.2-2.2), cg23652916-PALB2 (OR = 2.83; 95% CI:1.7-4.7), cg47630224-MSH2 (OR = 4.17; 95% CI:2.1-8.5), and cg47596828-EPCAM (OR = 1.84; 95% CI:1.5-2.3). Validation of cg47630224-MSH2 methylation in one Australian cohort showed an association with 3-fold increased BC risk (AUC: 0.929; 95% CI: 0.904-0.955). Our findings suggest that four DNA methylation CpG sites may be associated with a higher risk of BC, potentially serving as biomarkers in patients without detectable coding mutations.
RESUMEN
BACKGROUND: Rural women have limited access to breast cancer education, which partially contributes to late diagnosis and treatment. In this pilot study, we tested the feasibility of implementing a school-based breast cancer educational program for adolescents in a rural Mexican community. We hypothesized that the adolescents' knowledge on breast cancer would increase as a result of the program, and that there would be intergenerational transmission of that knowledge to their older female relatives. MATERIALS AND METHODS: Female adolescents from a rural middle school received the educational program. The program would be considered feasible and acceptable if more than 75% reported being satisfied with its contents. Changes in knowledge in the students and their relatives were evaluated using baseline and 4 months follow-up questionnaires. RESULTS: One hundred twenty-six students were enrolled. The program was considered acceptable by 96% of the participants. The students' knowledge regarding breast cancer increased significantly from baseline to 4 months follow-up (63% to 82%). One hundred ninety-four female relatives completed the initial knowledge questionnaires. The relatives' knowledge regarding breast cancer showed a significant increase from baseline to 4 months follow-up (55% to 61%). CONCLUSION: Implementing breast cancer educational programs for adolescents in rural communities is feasible and acceptable. The program increased the adolescents' knowledge on breast cancer, and promoted the intergenerational transmission of that knowledge to their female relatives. Intergenerational transmission of knowledge represents a potential method for providing population-based health awareness education globally. IMPLICATIONS FOR PRACTICE: In limited-resource settings, education is a valuable tool for achieving early detection and downstaging of breast cancer. Unfortunately, rural women lack access to educational opportunities and information about breast cancer, which is a factor contributing to late diagnosis and treatment. In this study, we demonstrated that implementing a school-based breast cancer educational program for female adolescents in a rural Mexican community was feasible, acceptable, and increased their knowledge about breast cancer. Furthermore, the program encouraged the transmission of information to the students' older relatives. Intergenerational transmission of knowledge represents a novel and potentially effective tool in cancer education and promotion.