A novel nomogram for predicting locoregional recurrence risk in breast cancer patients treated with neoadjuvant chemotherapy and mastectomy.

BACKGROUND: This study aimed to establish a nomogram for predicting locoregional recurrence (LRR) in breast cancer patients treated with neoadjuvant chemotherapy (NAC) and mastectomy. METHODS: A total of 2368 patients who received NAC and mastectomy between 2000 and 2014 from 12 grade A tertiary hospitals in China were analyzed retrospectively. The nomogram was developed based on the patients treated in three cancer hospitals (training set, n = 1629) and validated based on patients from the other nine general hospitals (validation set, n = 739). Factors identified from Fine and Gray's competing risk analysis were used to establish the nomogram. The predictive performance of the nomogram model was compared with the cTNM stage, ypTNM stage, and the Neo-Bioscore model by using the area under the time dependent receiver operating characteristic curves (tAUC), calibration curve, and decision curve analysis (DCA). RESULTS: The nomogram incorporated six risk factors derived from multivariable analysis of the training set including age, ypT stage, ypN stage, lymph node ratio, postmastectomy radiotherapy, and endocrine therapy. In the training set, the AUC of the nomogram was 0.792, which was higher than the values of the cTNM stage (0.582), ypTNM stage (0.737), and the Neo-Bioscore prognosis model (0.658). In the validation set, the AUC of the cTNM (0.619); ypTNM (0.636); and Neo-Bioscore staging system (0.584) were also significantly lower than the AUC of the nomogram (0.705). Both in the training and validation sets, the calibration curve showed good agreement between the nomogram-based predictions and the actual observations. CONCLUSION: The novel nomogram provides a more accurate evaluation of LRR for breast cancer patients treated with NAC and mastectomy.

Postmastectomy Radiation Therapy Based on Pathologic Nodal Status in Clinical Node-Positive Stage II to III Breast Cancer Treated with Neoadjuvant Chemotherapy.

PURPOSE: The present study aimed to evaluate the effect of postmastectomy radiation therapy (PMRT) after neoadjuvant chemotherapy in patients with node-positive stage II to III (cT1-4N1-2M0) breast cancer. METHODS AND MATERIALS: A total of 1813 patients from 12 institutions were retrospectively reviewed. Patients were classified into 1 of 3 groups based on the pathologic lymph node status after neoadjuvant chemotherapy: ypN0, ypN1, and ypN2-3. The role of PMRT was separately evaluated in each group. Locoregional control, disease-free survival, and overall survival (OS) were estimated using the Kaplan-Meier method. The effect of PMRT was assessed by propensity score-matched analyses and multivariate Cox analyses. RESULTS: With a median follow-up of 72.9 months, 5-year locoregional control, disease-free survival, and OS rates were 86.3%, 68.4%, and 83.1% for the entire cohort, respectively. There were 490 (27.0%), 567 (31.3%), and 756 (41.7%) patients in the ypN0, ypN1, and ypN2-3 groups, respectively. PMRT significantly improved 5-year OS in the ypN2-3 group (74.2% vs 55.9%; P < .001) but had no effect on 5-year OS in the ypN0 group (93.1% vs 95.5%; P = .517) and ypN1 group (88.4% vs 87.8%; P = .549). CONCLUSIONS: With modern systemic therapy, PMRT significantly improved OS in the ypN2-3 group but not in the ypN0 and ypN1 groups. Whether PMRT can be safely omitted in the ypN0 and ypN1 groups should be addressed prospectively.