Risk-Adapted Postmastectomy Radiotherapy Decision Based on Prognostic Nomogram for pT1-2N1M0 Breast Cancer: A Multicenter Study.

The aim of this study was to develop a widely accepted prognostic nomogram and establish a risk-adapted PMRT strategy based on locoregional recurrence for pT1-2N1M0 breast cancer. A total of 3,033 patients with pT1-2N1M0 breast cancer treated at 6 participating institutions between 2000 and 2016 were retrospectively reviewed. A nomogram was developed to predicted locoregional recurrence-free survival (LRFS). A propensity score-matched (PSM) analyses was performed in risk-adapted model. With the median follow-up of 65.0 months, the 5-year overall survival (OS), disease free survival (DFS) and LRFS were 93.0, 84.8, and 93.6%, respectively. There was no significant difference between patients who received PMRT or not for the entire group. A nomogram was developed and validated to estimate the probability of 5-year LRFS based on five independent factors including age, primary tumor site, positive lymph nodes number, pathological T stage, and molecular subtype that were selected by a multivariate analysis of patients who did not receive PMRT in the primary cohort. According to the total nomogram risk scores, the entire patients were classified into low- (40.0%), moderate- (42.4%), and high-risk group (17.6%). The 5-year outcomes were significantly different among these three groups (P<0.001). In low-risk group, patients who received PMRT or not both achieved a favorable OS, DFS, and LRFS. In moderate-risk group, no differences in OS, DFS, and LRFS were observed between PMRT and no PMRT patients. In high-risk group, compared with no PMRT, PMRT resulted in significantly different OS (86.8 vs 83.9%, P = 0.050), DFS (77.2 vs 70.9%, P = 0.049), and LRFS (90.8 vs. 81.6%, P = 0.003). After PSM adjustment, there were no significant differences in OS, DFS, and LRFS in low-risk and moderate-risk groups. However, in the high-risk group, PMRT still resulted in significantly better OS, DFS and improved LRFS. The proposed nomogram provides an individualized risk estimate of LRFS in patients with pT1-2N1M0 breast cancer. Risk-adapted PMRT for high-risk patients is a viable effective strategy.

Li M ，Yue J ，Wan X ，Hua B ，Yang Q ，Yang P ，Zhang Z ，Pei Q ，Han W ，Xu Y ，Xia X ... -  《Frontiers in Oncology》

[Risk-adapted postmastectomy radiotherapy based on local-regional recurrence for T1-2N1M0 breast Cancer].

Li M ，Wang SL ，Fang H ，Tang Y ，Chen B ，Qi SN ，Song YW ，Liu YP ，Lu NN ，Li N ，Tang Y ，Ren H ，Jin J ，Li YX ... -  《-》

The significance of risk stratification through nomogram-based assessment in determining postmastectomy radiotherapy for patients diagnosed with pT(1 - 2)N(1)M(0) breast cancer.

Wei C ，Kong J ，Han H ，Wang X ，Gao Z ，Wang D ，Zhang A ，Zhang J ，Liu Z ... -  《Radiation Oncology》

Postmastectomy radiotherapy improves disease-free survival of high risk of locoregional recurrence breast cancer patients with T1-2 and 1 to 3 positive nodes.

He ZY ，Wu SG ，Zhou J ，Li FY ，Lin Q ，Lin HX ，Sun JY ... -  《PLoS One》

The prognostic differences and the effect of postmastectomy radiotherapy between post-chemotherapy ypT1-2ypN1 and de novo pT1-2N1 breast cancer.

The prognosis and the value of postmastectomy radiotherapy (PMRT) between post-chemotherapy ypT1-2ypN1 and de novo pT1-2N1 breast cancer (BC) remain controversial. We aimed to evaluate the prognostic differences and the effect of PMRT between the two patient subsets. Patients diagnosed with pT1-2N1M0 BC were identified between 2010 and 2018. The study endpoints were overall survival (OS), breast cancer-specific survival (BCSS), locoregional recurrence-free survival (LRFS), distant metastasis-free survival (DMFS) and disease-free survival (DFS). The chi-square test, Kaplan-Meier method and Cox regression analysis were used for data analysis. Total number of 2103 pT1-2N1M0 BC patients were included in the study, including 270 post-chemotherapy (97 without PMRT, 173 with PMRT) and 1833 de novo cases (993 without PMRT, 840 with PMRT). No significant differences were found between post-chemotherapy ypT1-2ypN1 and de novo pT1-2N1 BC patients in 5-year OS (p = 0.068), BCSS (p = 0.054), LRFS (p = 0.241), DMFS (p = 0.104) or DFS (p = 0.08). PMRT did not improve any survival outcome in patients receiving neoadjuvant chemotherapy; however, the PMRT group had a better 5-year BCSS (97.0% vs. 95.8%, p = 0.033) in de novo pT1-2N1 BC. Cox multivariate analysis demonstrated that PMRT was a significant independent predictor of BCSS (HR 0.628; 95% CI, 0.403-0.978; p = 0.04) in de novo pT1-2N1 patients. There seemed no survival difference in post-chemotherapy ypT1-2ypN1 and de novo pT1-2N1 BC patients with contemporary systemic therapy. In addition, PMRT might be exempted in patients with post-chemotherapy ypT1-2ypN1 BC, while not in patients with de novo pT1-2N1 BC.

Yang T ，Zhong X ，Wang J ，Xiang Z ，Zeng Y ，Yu S ，Dai Z ，Xu N ，Luo T ，Liu L ... -  《Cancer Medicine》