Predictors of locoregional outcome in patients receiving neoadjuvant therapy and postmastectomy radiation.

BACKGROUND

The objective of this study was to identify predictors of locoregional recurrence (LRR) after neoadjuvant therapy (NAT) and postmastectomy radiation (PMRT) in a cohort of patients with stage II through III breast cancer and to determine whether omission of the supraclavicular field had an impact on the risk of LRR.

METHODS

The authors reviewed records from 464 patients who received NAT and PMRT from January 1999 to December 2009.

RESULTS

The median patient age was 50 years (range, 25-81 years). Clinical disease stage was stage II in 29% of patients, stage III in 71%, and inflammatory in 14%. Receptor status was estrogen receptor (ER)-positive in 54% of patients, progesterone receptor (PR)-positive in 39%, human epidermal growth factor receptor 2 (HER2)-positive in 24%, and negative for all 3 receptors (triple negative) in 32%. All patients received NAT and underwent mastectomy, and 19.6% had a complete pathologic response in the breast and axilla, 17.5% received radiation to the chest wall only, and 82.5% received radiation to the chest wall and the supraclavicular field; omission of the supraclavicular field was more common in patients with lower clinical and pathologic lymph node status. The median follow-up was 50.5 months, and the 5-year cumulative incidence of LRR was 6% (95% confidence interval, 3.9%-8.6%). Predictors of LRR were clinical stage III (P = .038), higher clinical lymph node status (P = .025), higher pathologic lymph node status (P = .003), the combination of clinically and pathologically positive lymph nodes (P < .001), inflammatory presentation (P = .037), negative ER status (P = .006), negative PR status (P = .015), triple-negative status (P < .001), and pathologic tumor size >2 cm (P = .045). On univariate analysis, omission of the supraclavicular field was not associated significantly with LRR (hazard ratio, 0.89; P = .833); however, on multivariate analyses, omission of the supraclavicular field was associated significantly with LRR (hazard ratio, 3.39; P = .024).

CONCLUSIONS

Presenting stage, receptor status, pathologic response to neoadjuvant therapy, and omission the supraclavicular field were identified as risk factors for LRR after neoadjuvant therapy and PMRT.