A 57-year-old woman with breast cancer was referred by her surgeon to see a genetic counselor because this was her second breast cancer diagnosis. Three years earlier, this patient had been tested for inherited pathogenic variants in BRCA1 and BRCA2 genes associated with increased risk of breast, ovarian, and other cancers. Although the patient reported that she was told this testing had yielded negative results, given her own experience with a prior breast cancer at age 38 and colon cancer at age 51, and a strong family history of breast, ovarian, and other cancers, the surgeon felt she could benefit from getting tested again with a broader panel of genes.
During her genetic counseling session, the patient again recounted how she had received genetic testing previously and that it had turned up negative for pathogenic variants in BRCA1/2. However, the patient also said that her sister, who had never had cancer, had also gotten genetic testing based on their family history of cancer around the same time she had. This testing revealed that her sister had a pathogenic variant in BRCA1 and another in MUTYH – a gene that is associated with a hereditary cancer syndrome that causes significantly increased risk of colon polyps and colon cancer if the individual has pathogenic variants in both copies of the gene; a pathogenic variant in one copy of the gene could also potentially increase colon cancer risk modestly.
To read the full article, click here.