Résumé
Abstract only e13151 Background: Intrafamilial disclosure of hereditary cancer predisposition in BRCA1/2 and mismatch repair gene (MMR) syndromes allows appropriate prevention strategies in at-risk relatives. We previously showed in a nationwide study that the uptake of genetic targeted testing (GTT) in these families by relatives was only 30%. We aimed to identify the medical and psychosocial factors affecting the proband’s intrafamilial disclosure and relatives’ uptake of GTT in BRCA1/2 or MMR syndromes. Methods: We assessed clinical variables, family history and several psychological variables of probands (depression, anxiety, alexithymia, optimism, coping, family relationship, perception of cancer risks and of hereditary transmission risks), together with disclosure and verified uptake of GTT in BRCA1/2 or MMR families. Results: Among relatives eligible for GTT, 68% were informed of the predisposition and 37% underwent GTT, according to proband reports. Intrafamilial disclosure was inversely associated with the degree of kinship (P < 0.01). In multivariable analysis, disclosure increased with time since proband’s genetic diagnosis (P < 0.01) and proband’s feeling of family cohesion (P = 0.01). GTT uptake increased with proband’s depression score (P = 0.02) and decreased with proband’s perception of cancer risks (P = 0.03). BRCA1/2 and MMR groups did not differ in findings concerning family information and GTT uptake. Conclusions: This study identified factors affecting disclosure to relatives and GTT uptake in BRCA1/2 and MMR syndromes and gives new insights to improve probands’ follow-up and intrafamilial sharing of genetic information.