Other cancer-related factors, such as breast cancer stage, BRCA1 and BRCA2 sequence variation, and other treatment modalities, were not associated with depression, which is consistent with the findings of previous studies investigating the association between depression and breast cancer.19,20,21 In line with previous research,22,23,24 we found that younger age, having a child, and a lower educational level were all independently correlated with depression. This evidence concerns the gene BRCA1 and cancer.