BACKGROUND

Completion axillary lymph node dissection (cALND) was standard treatment for breast cancer with positive sentinel lymph nodes (SLNs) until 2011, when data from the Z11 and AMAROS trials challenged its survival benefit in early stage breast cancer. We assessed the contribution of patient, tumor, and facility factors on cALND use in patients undergoing mastectomy and SLN biopsy.

PATIENTS AND METHODS

Using the National Cancer Database, patients diagnosed from 2012 to 2017 who underwent upfront mastectomy and SLN biopsy with at least one positive SLN were included. A multivariable mixed effects logistic regression model was used to determine the effect of patient, tumor, and facility variables on cALND use. Reference effect measures (REM) were used to compare the contribution of general contextual effects (GCE) to variation in cALND use.

RESULTS

From 2012 to 2017, the overall use of cALND decreased from 81.3% to 68.0%. Overall, younger patients, larger tumors, higher grade tumors, and tumors with lymphovascular invasion were more likely to undergo cALND. Facility variables, including higher surgical volume and facility location in the Midwest, were associated with increased use of cALND. However, REM results showed that the contribution of GCE to the variation in cALND use exceeded that of the measured patient, tumor, facility, and time variables.

CONCLUSIONS

There was a decrease in cALND use during the study period. However, cALND was frequently performed in women after mastectomy found to have a positive SLN. There is high variability in cALND use, mainly driven by interfacility practice variation rather than specific high-risk patient and/or tumor characteristics.