Physician Specialization and Receipt of Updated Breast Cancer Care in the United States: A SEER-Medicare Analysis.

PURPOSE

Advances in breast cancer treatment have reduced mortality and toxicity, but it remains unclear which patients receive updated care and when. We aimed to identify factors associated with receiving updated breast cancer care.

METHODS

We analyzed patients age 65-85 years with local or regional breast cancer, diagnosed between 2010 and 2018, using the SEER-Medicare database. We included patients who were continuously enrolled in Medicare for 1 year after diagnosis and were eligible for one of four updated treatments: (1) adjuvant paclitaxel-trastuzumab (APT) for human epidermal growth factor receptor 2 (HER2)-positive local disease, (2) pertuzumab for HER2-positive regional disease, (3) neoadjuvant chemotherapy for triple-negative or HER2-positive regional disease, and (4) omission of chemotherapy for hormone receptor-positive, HER2-negative regional disease. We examined the association between treating oncologist specialization (percent of SEER-Medicare patients with breast cancer) and receipt of updated care using multivariable analysis.

RESULTS

Of the 21,575 patients eligible for one of these four updated care approaches, use of the APT regimen increased from 30% (95% CI, 23% to 37%) to 72% (95% CI, 67% to 77%), pertuzumab from 0% to 71% (95% CI, 66% to 76%), neoadjuvant chemotherapy from 23% (95% CI, 18% to 28%) to 60% (95% CI, 56% to 65%), and omission of chemotherapy from 54% (95% CI, 52% to 57%) to 61% (95% CI, 59% to 64%) from 2010 to 2018. In multivariable analyses, higher median income of residence county and greater specialization of treating oncologist were statistically significantly associated with receipt of updated care for all four treatment scenarios. Patients from lower-income areas who received care from more specialized oncologists were as likely to receive updated care as those from higher-income areas.

CONCLUSION

Patients from lower-income areas were less likely to receive updated care, but specialized oncologists helped mitigate this disparity. Care models that expand consultative access to specialized oncologists should be prioritized for evaluation.