Population-based analysis of non-operative management and treatment patterns in older women with estrogen receptor-positive breast cancer

Purpose To examine the proportion of older women with ER + HER2- breast cancer receiving non-operative management versus surgery, and to evaluate the use of axillary staging and adjuvant radiation in this population. Methods We queried the SEER database to identify all women aged 70 years or older with stage I-III ER + HER2- invasive breast cancer diagnosed between 2010 and 2016. We evaluated trends in non-operative management, breast surgery, axillary staging, and adjuvant radiation according to age at diagnosis. Results We identified 57,351 older women with ER + HER2- disease. Overall, 3538 (6.2%) of the cohort underwent non-operative management, 38,452 (67.0%) underwent breast-conserving surgery (BCS), and 15,361 (26.8%) underwent mastectomy. The proportion of patients undergoing non-operative management increased from 2.8% among 70-74-year-old women to 30.1% in those >= 90 years old (p < 0.001). In 53,813 women who underwent surgery, 36,850 (68.5%) underwent sentinel lymph node biopsy, while 10,861 (20.2%) underwent axillary lymph node dissection. Subgroup analysis of 29,032 older women undergoing BCS for stage I ER + HER2- breast cancer revealed a 14.2% rate of omission of axillary staging, increasing from 5.3% in those 70-74 years to 67.6% in those >= 90 years old (p < 0.001). Receipt of adjuvant radiation occurred in 63.3% of older women following BCS and 18% post-mastectomy, with similar trends towards omission in older age groups. Conclusion Primary breast surgery remains the dominant management strategy for the majority of older women with ER + HER2- breast cancer. Omission of axillary staging and adjuvant radiation are used in a minority of eligible women undergoing breast conservation for early-stage disease.

Automated summary

The majority of older women with ER + HER2- breast cancer tend to undergo primary breast surgery as the dominant management strategy, but omission of axillary staging and adjuvant radiation is seen in a minority of eligible women undergoing breast conservation for early-stage disease, with a more pronounced trend as age increases.