Unnecessary axillary lymph node dissection in the era of sentinel lymph node biopsy. J Clin Oncol 2015 Oct;33(28_suppl):71
Date
10/01/2015Pubmed ID
28147752Abstract
: 71 Background: No population-based effectiveness studies have been performed to determine to what extent breast cancer patients are benefiting from sentinel lymph node biopsy (SLNB). This study investigates the extent of unnecessary axillary lymph node dissection (ALND) by surgeon volume and specialty, and estimates the resultant rates of excess lymphedema (LE).
METHODS: Women with Stage I-III pathologically node-negative (pN0) breast cancer diagnosed in 2008-2009 were identified from the SEER-Medicare linked database. Patients who received neoadjuvant chemotherapy were excluded. Type of axillary surgery was defined by claims. Unnecessary ALND was defined as a patient who underwent either an initial ALND or SLNB followed by ALND. Surgeon volume tertiles were created with roughly a third of cases in each volume group (low, medium, high). Surgical specialty (surgical oncologist, general, other) was determined by the specialty code listed on the claim. A logistic regression model, adjusting for patient and tumor characteristics, was performed to predict the likelihood of receiving an unnecessary ALND. Estimates of LE rates were determined based on the number of nodes removed.
RESULTS: 7,946 pN0 patients underwent surgery by 2,101 surgeons. Half underwent SLNB only; 50% had unnecessary ALND (39% converted from SLNB to ALND, 11% ALND only). There was an interaction between surgeon volume and specialty (p < 0.01); surgical oncologists, compared to non-surgical oncologists, were less likely to perform unnecessary ALND in all three volume groups. This effect was largest in the medium volume group (OR 0.37; 95% CI: 0.26-0.51). The LE probability was 14% with an excess LE rate of 4.5%. Unnecessary ALNDs accounted for 84% of the estimated excess LE patients and represented 27% of all potentially avoidable LE cases.
CONCLUSIONS: Half of pN0 patients underwent unnecessary ALNDs, which accounts for 27% of all potentially avoidable LE cases. The likelihood of undergoing an unnecessary ALND was lower in all three surgeon volume groups if patients were operated on by surgical oncologists. Policies to assess surgeon proficiency in SLNB and/or regionalization of care should be considered to decrease rates of unnecessary ALND and ultimately LE.
Author List
Laud PW, Pezzin LE, McGinley E, Wozniak E, Sparapani RA, Nattinger ABAuthors
Ann B. Nattinger MD, MPH Associate Provost, Professor in the Medicine department at Medical College of WisconsinLiliana Pezzin PhD, JD Professor in the Institute for Health and Equity department at Medical College of Wisconsin
