Are Broadened Guidelines Improving our Detection of Pathologic Genetic Mutations in Breast Cancer Patients? A 5-Year Comparative Analysis of American Society of Breast Surgeons and National Comprehensive Cancer Network Guidelines.

INTRODUCTION

In 2019, the American Society of Breast Surgeons expanded genetic testing (GT) criteria as some pathologic genetic mutations (PGM) were missed when adhering to National Comprehensive Cancer Network (NCCN) guidelines. We sought to evaluate our institutional detection of PGM and to understand what patient factors can be predictive of detection.

METHODS

We conducted a retrospective cohort study of patients who had GT performed in association with a diagnosis of breast cancer from April 2019-2024 at our institution. Patient demographic and GT data were collected from the electronic medical record. The NCCN and non-NCCN cohorts were compared, and multivariable analyses were performed.

RESULTS

A total of 933 patients were analyzed; 859 (92.1%) of those patients met NCCN guidelines. The PGM detection rate was 9.5% in the ASBrS cohort and 9.9% in the NCCN cohort. There was no difference in the PGM detection rates between the non-NCCN and NCCN cohort (p = 0.3). Of the 89 patients with PGM, 5.4% were in the non-NCCN cohort. Patients with invasive lobular and ductal carcinoma were significantly more likely to have PGM than those with other subtypes. Patients with an age at diagnosis > 50 trended toward being less likely to have PGM than those ≤ 50. Patients with a personal history of cancer tended to be more likely to have PGM than those without.

CONCLUSIONS

At our single institution during the past 5 years, we captured more patients with an actionable PGM through broader GT criteria, suggesting that patients with actionable PGM can be missed with more stringent guidelines.