Tumor Response Ratio Predicts Overall Survival in Breast Cancer Patients Treated with Neoadjuvant Chemotherapy
- 380 Downloads
Neoadjuvant chemotherapy (NAC) is commonly used to treat locally advanced breast cancer. Pathologic complete response (pCR) predicts improved overall survival (OS); however, prognosis of patients with partial response remains unclear. We evaluated whether tumor response ratio (TRR) is a better predictor of OS than current staging methods.
Using the National Comprehensive Cancer Network Breast Cancer Outcomes Database, we identified patients with stage I–III breast cancer who had NAC and pretreatment imaging at City of Hope (1997–2010). Patient demographics, tumor characteristics, and OS were analyzed. TRR was calculated as residual in-breast disease divided by size on pre-NAC imaging. Four TRR groups were stratified; TRR 0 (pCR), TRR > 0–0.4 (strong partial response, SPR), TRR > 0.4–1.0 (weak partial response, WPR), or TRR > 1.0 (tumor growth, TG). OS was estimated by the Kaplan–Meier method and tested by the log-rank test. Cox regression was performed to evaluate associations between OS and TRR in a multivariable analysis while controlling for potential confounders.
There were 218 eligible patients identified; 59 (27 %) had pCR, 61 (28 %) SPR, 72 (33 %) WPR, and 26 (12 %) TG. Five-year OS decreased continuously with increasing TRR:pCR (90 %), SPR (79 %), WPR (66 %), and TG (60 %). TRR was the only measure that significantly predicted OS (p = 0.0035); pathologic stage (p = 0.23) and pre-NAC clinical tumor stage (cT) (p = 0.87) were not significant. TRR continued to be statistically significant by multivariable analysis (p = 0.016).
TRR takes into account both pretreatment and residual disease and more accurately predicts OS than pathologic stage and pre-NAC cT. TRR may be useful to more accurately assess prognosis and OS in breast cancer patients undergoing NAC.
KeywordsOverall Survival National Comprehensive Cancer Network Pathologic Stage National Comprehensive Cancer Network Residual Cancer Burden
The authors thank Nicola Solomon, PhD, for editorial assistance.
The authors declare no conflict of interest.
- 2.Edge SB, Compton CC, Fritz AG, et al. American Joint Committee on Cancer (AJCC) cancer staging manual. 7th ed. Chicago: Springer; 2010.Google Scholar
- 11.Bear HD, Anderson S, Brown A, et al. The effect on tumor response of adding sequential preoperative docetaxel to preoperative doxorubicin and cyclophosphamide: preliminary results from National Surgical Adjuvant Breast and Bowel Project Protocol B-27. J Clin Oncol. 2003;21:4165–74.PubMedCrossRefGoogle Scholar
- 13.Wolmark N, Wang J, Mamounas E, Bryant J, Fisher B. Preoperative chemotherapy in patients with operable breast cancer: nine-year results from National Surgical Adjuvant Breast and Bowel Project B-18. J Natl Cancer Inst Monogr. 2001;30:96–102.Google Scholar
- 15.Baselga J, Bradbury I, Eidtmann H, et al. Lapatinib with trastuzumab for HER2-positive early breast cancer (NeoALTTO): a randomised, open-label, multicentre, phase 3 trial. Lancet. 2012;379(9816):633–40 (Erratum in: Lancet. 2012;379(9816):616).Google Scholar