C. E. Collins2, S. Naffouje4, M. C. Lee1, S. Hoover1, R. Diaz3, W. Sun1, C. Laronga1 1Moffitt Cancer Center And Research Institute, Breast Oncology Program, Tampa, FL, USA 2Wake Forest University, Winston-Salem, NC, USA 3Moffitt Cancer Center And Research Institute, Radiation Oncology Program, Tampa, FL, USA 4Moffitt Cancer Center And Research Institute, Department Of Surgical Oncology, Tampa, FL, USA
Introduction:
De-escalation of care of early-stage invasive breast cancer is trending in geriatric (≥70 years of age) patients. Society of Surgical Oncology Choosing Wisely guideline and recent clinical trials recommend omission of sentinel lymph node biopsy and/or whole breast radiation therapy in clinically-node negative geriatric women with hormone receptor (HR)+, HER2-, early-stage breast cancer. We investigated management trends and survival outcomes in this population.
Methods:
We utilized the National Cancer Database (NCDB) to analyze women ≥ 70 years of age with early-stage (cT1N0M0), HR+, HER2- breast cancer, limiting to ductal histology (IDC). Criteria selection included patients with reported data on type of breast surgery [lumpectomy (BCS) vs. mastectomy (Mx)], delivery of breast radiation therapy (XRT), and use of sentinel lymph node biopsy (SLNB). Treatment choices were stratified and observed for chronological occurrence and variation between decimal age groups. Comparison of baseline demographic and clinical characteristics was performed using conditional logistic regression. We performed multivariable regression analyses to identify predictors of observation over surgery, omission of SLNB in those having surgery, and node-positivity in those who had SLNB. Using a propensity score method, we matched patients who received XRT to those who didn’t, and similarly SLNB vs. no SLNB. Utilizing these matched groups, we compared overall survival (OS) using the Kaplan Meyer survival analysis method.
Results:
110,638 geriatric female patients with unilateral, cT1N0M0, HR+ HER2- IDC with available report on locoregional management of the breast and axilla were selected. 95.4% of the population underwent breast resection and the most common locoregional management plan was BCS + XRT + SLNB (42.8%). When the population was divided into decile age groups (70s, 80s, 90s), rates of BCS + SLNB (21.2% to 13.7%), BCS + XRT + SLNB (50.7% to 4.5%), and Mx + SLNB (16.6% to 7.4%) all decreased. Chronological trends revealed a slight decrease in BCS + XRT + SLNB (45% to 41%) and Mx + SLNB (20% to 13%). Kaplan Meier analysis of the matched SLNB vs. No-SLNB groups showed no difference in OS with an identical five-year OS of 80% (p=0.611). Comparison of the matched XRT vs. No-XRT groups showed a significant difference in OS with an absolute five-year OS difference of 1% (88% vs. 87%; p=0.010).
Conclusion:
Omitting SLNB does not have an impact on overall survival in the selected population. Although significant, clinical relevance of an absolute OS of 1% with delivery of XRT is to be determined. Therefore, de-escalation in treatment among breast cancer patients who meet the criteria is supported as a safe management option.
