Cost‐effectiveness of Choosing Wisely guidelines for axillary observation in women older than age 70 years with hormone receptor–positive, clinically node‐negative, operable breast tumors.

Background: The Society for Surgical Oncology's Choosing Wisely guidelines recommend against sentinel lymph node biopsy (SLNB) in favor of observation in this population. Recent analyses reveal that this has not been widely adopted. The purpose of this cost‐effectiveness analysis is to compare the costs and benefits associated with observation or SLNB in women >70 years old with hormone receptor–positive, clinically node‐negative, operable breast cancer. Methods: A decision tree with Markov modeling was created to compare treatment strategies using long‐term follow‐up data from clinical trials in this population. Costs were estimated from published literature and publicly available databases. Breast cancer–specific health‐state utilities were derived from the literature and expert opinion. One‐way, 2‐way, and probabilistic sensitivity analyses were conducted. A structural sensitivity analysis was performed to assess the effect of functional status and anxiety from nonevaluation of the axilla on cost‐effectiveness. Costs and benefits, measured in life‐years (LYs) and quality‐adjusted life‐years (QALYs), were tabulated across 10, 15, and 20 years and compared using incremental cost‐effectiveness ratios (ICERs). Results: SLNB is not cost‐effective from the payer or societal perspectives with ICERs of $138,374/LY and $131,900/LY, respectively. When QALYs were considered, SLNB provided fewer QALYs (SLNB, 10.33 QALYs; observation, 10.53 QALYs) at a higher cost (SLNB, $15,845; observation, $4020). Structural sensitivity analysis revealed that SLNB was cost‐effective in certain patients with significant anxiety related to axillary observation (ICER, $39,417/QALY). Conclusions: Routine SLNB in this population is not cost‐effective. The cost‐effectiveness of SLNB, however, is dependent on individual patient factors, including functional status as well as patient preference. [ABSTRACT FROM AUTHOR]