Radiographic Surveillance of Patients with Non-BRCA1/2 Pathogenic Variants

The National Comprehensive Cancer Network (NCCN) developed clinical practice guidelines for germline pathogenic variants in highly penetrant genes, such as TP53 and PTEN, and in moderately penetrant genes, such as CHEK2, ATM and PALB2. Whether the practice of radiographic surveillance of patients with pathogenic variants in genes other than BRCA1/2 complies with current NCCN guidelines remains unclear.

Retrospective review of patients identified with pathogenic variants in genes other than BRCA1/2 from 2007 through 2017 to determine if radiographic surveillance was in accordance with NCCN guidelines for mammography and consideration of magnetic resonance imaging (MRI). Exclusions included variants of unknown significance, pathogenic variants not associated with an increased risk of breast cancer, and previous breast cancer diagnosis.

After exclusions, 35 patients with pathogenic variants in ATM, CDH1, CHEK2, NBN, PALB2, PTEN, and STK11 genes were reviewed to assess whether radiographic surveillance was in accordance with NCCN guidelines. Guidelines for those with variants in ATM, CHEK2 and NBN includes annual mammography with tomosynthesis and consideration of breast MRI at age 40, variants in CDH1 and PALB2 at age 30, variants in PTEN at age 30-35 or 5-10 years before the earliest family breast cancer, and variants in STK11 at age 25. Of these 35 patients, 11 (31%) received mammography only; 11 (31%) received mammography and MRI, and 13 (37%) received no radiographic surveillance. Two of the 35 (6%) patients who received radiographic surveillance were diagnosed with ductal carcinoma in situ or invasive breast cancer.

Thirty-one percent of patients with pathogenic variants in genes other than BRCA1/2 received both mammography and MRI. Thirty-seven percent of patients with these highly penetrant and moderately penetrant genes received no radiographic follow-up, clearly demonstrating an opportunity for improvement.