Genetic cancer risk knowledge among Mexican pathogenic variant carriers

To assess knowledge of genetic cancer risk among Mexican carriers of cancer-associated pathogenic variants (PVs) using the Spanish version of the KnowGene Cancer Genetics Questionnaire, and to examine whether knowledge is associated with uptake of risk-reducing surgery (RRS) or cascade testing (CT).

We conducted a cross-sectional study of adult PV carriers who had received post-test genetic cancer risk assessment (GCRA) at two referral centers in Mexico. Participants completed the 16-item KnowGene Cancer Genetics Questionnaire assessing inheritance, result interpretation, clinical implications, and screening/risk reduction. Sociodemographic and clinical data were collected. Associations between knowledge scores and participant characteristics were evaluated using univariate analyses and multivariable linear regression. Associations between knowledge and uptake of RRS and CT were explored descriptively.

Among 384 eligible carriers, 261 (68.0 %) completed the questionnaire. Median age was 44 years (range 20-77); 87.0 % were female, and 63.2 % were probands. The most frequent PVs were BRCA1 (36.8 %) and BRCA2 (25.7 %). The mean knowledge score was 9.42 out of 16 (SD 3.0), with item-level gaps most pronounced in inheritance and interpretation of variants of uncertain significance. Higher educational attainment was independently associated with higher knowledge scores in multivariable analysis (β = 1.92, p < 0.001). Knowledge scores were not significantly associated with uptake of RRS or CT.

Mexican carriers of cancer-associated PVs demonstrated moderate genetic knowledge after GCRA, with persistent gaps in clinically relevant concepts. Educational attainment was the primary determinant of knowledge, but greater knowledge alone did not translate into higher uptake of preventive interventions.

GCRA programs should incorporate tailored, patient-centered communication strategies and address structural and psychosocial barriers to improve informed decision-making and engagement with recommended preventive actions.