ASCO Quality 2022: Causes of Variation in Receipt of Axillary Surgery in Older Patients With Breast Cancer

By: Sarah Lynch
Posted: Wednesday, October 12, 2022

Researchers at Brigham and Women’s Hospital, Boston, have evaluated the causes of variation in receipt of axillary surgery for patients with T1N0 hormone receptor (HR)-positive breast cancer. Three models were created and analyzed, and it was determined that most of the variation seems to stem from differences at the patient level, rather than at the surgeon level. These findings were presented at the 2022 American Society of Clinical Oncologists (ASCO) Quality Care Symposium (Abstract 284).

“Drivers of residual patient-level variation may include unmeasured factors such as differences in surgeon-patient communication and patient preferences,” reported Christina Ahn Minami, MD, and colleagues.  

The study included 4,410 women older than 70 with T1N0 HR-positive/HER2-negative breast cancer and 432 surgeons. Three models were created to analyze axillary surgery variance. The first was a null model, in which hierarchal logistic regression models on surgeon-specific random intercepts were estimated. For the second model, the data from the null model were estimated again, this time accounting for patient demographic information, such as age, Charlson Comorbidity Index, and a claims-based frailty index. The final model included other surgeon-, patient-, and disease-level factors. The researchers used the intracluster correlation to estimate the amount of variance attributable to surgeon-level differences.

According to the null model, 10.5% of variance was attributable to surgeon-level differences, and the rest to patient-level. The model adjusted for patient variables brings the surgeon-level variance up to 13%. Lastly, the final model determined that patients with breast cancer treated by female surgeons seemed to be less likely to undergo axillary surgery as part of their diagnosis and treatment plan.

Thus, the researchers were able to determine that most of the axillary surgery variation in older patients was due to patient-level differences. The remaining variation, they inferred, was due to differences in patient preferences and the communication between surgeons and patients.

Disclosure: For full disclosures of the study authors, visit meetings.asco.org.

2022 ASCO Quality Care Symposium

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