Hereditary Cancer-Associated Mutations in Women Diagnosed with Two Primary Cancers: An Opportunity to Identify Hereditary Cancer Syndromes after the 1st Cancer Diagnosis

Myriad Genetics - open access - full text

 Abstract

Objectives: Patients with hereditary cancer syndromes are at high risk for a second primary cancer. Early identification of these patients after an initial cancer diagnosis is the key to implementing cancer risk-reducing strategies.  

Methods: A commercial laboratory database was searched for women with a history of both breast and ovarian or colorectal and endometrial cancer who underwent genetic testing for hereditary breast and ovarian cancer (HBOC) or Lynch syndrome (LS).  

Results: Among women with both breast and ovarian cancer, 22.4% (2,237/9,982) had a BRCA1 or BRCA2 mutation. Among women with both colorectal and ovarian cancer, 28.1% (264/941) had a mutation associated with LS. In 66.6% of BRCA1 or BRCA2 mutation carriers and in 58.3% of LS mutation carriers, >5 years passed between the cancer diagnoses. Of patients with HBOC and LS, 56 and 65.2%, respectively, met the National Comprehensive Cancer Network guidelines for hereditary cancer testing after their initial diagnosis based on their personal cancer history alone.  

Conclusions: A substantial number of women tested for LS or HBOC after being diagnosed with two successive primary cancers were diagnosed with a hereditary cancer syndrome. In many cases, the time interval between the diagnoses was long enough to allow for the implementation of surveillance and/or prophylactic measures.

".... Many of the women in the present analysis were diagnosed with breast cancer after the age of 45 but they may still have qualified for testing based on family history or triple negative status. It is especially important to survey women with HBOC after a breast cancer diagnosis because many of them will survive their breast cancer but remain at risk for ovarian cancer, which has a higher mortality rate......Furthermore, it reinforces the role of gynecologists and gynecologic oncologists in supporting genetic testing for patients with endometrial cancer, as nearly half of all patients with LS present first with a gynecologic cancer.....Of note, a 5-year remission is a common oncology mark after which a patient is considered cancer-free. The data presented here suggest that patients with hereditary cancer syndromes are still vulnerable to a second diagnosis after the 5-year mark.....