BACKGROUND: Recent data support the use of post-mastectomy radiation therapy (PMRT) in women with one to three positive lymph nodes; however, the benefit of PMRT in patients with micrometastatic nodal disease (N1mi) is unknown. We evaluated the survival impact of PMRT in patients with N1mi within the National Cancer Database. METHODS: The pattern of care and survival benefit of PMRT was examined in women with pT1-2N1mi breast cancer who underwent mastectomy without neoadjuvant chemotherapy. Univariable and multivariable Cox proportional hazard models were employed for survival analysis, and subanalyses of high-risk patients and a propensity score-matched (PSM) cohort were completed. RESULTS: From 2004 to 2014, we identified 14,019 patients who fitted the study criteria. PMRT was delivered in 18.5% of patients and its use increased over the study period. Patients treated with PMRT were younger, had better performance status and larger primaries, were estrogen receptor (ER)-negative, had higher grade, lymphovascular invasion and positive surgical margins, and more often received systemic therapy. PMRT was significantly associated with overall survival (OS) in univariable analysis (hazard ratio [HR] 0.75 [0.64-0.89]), but was not significant in multivariable analysis (adjusted HR 1.01 [0.84-1.20]). There was no survival benefit to PMRT in ER-negative, high-grade, and/or young patients. There were 2 (0.9%) death events in the sentinel lymph node biopsy (SLNB) + PMRT group versus 21 (2.9%) in the SLNB-alone group (log-rank p = 0.053), and 8 (3.9%) death events in the axillary lymph node biopsy (ALNB) + PMRT group versus 27 (3.6%) in the axillary lymph node dissection-alone group (p = 0.82). There was no significant association between PMRT and OS within the PSM subgroup. CONCLUSION: In this largest reported retrospective study, no OS differences were associated with PMRT, which suggests that PMRT may not benefit every patient with microscopic nodal disease.
BACKGROUND: Recent data support the use of post-mastectomy radiation therapy (PMRT) in women with one to three positive lymph nodes; however, the benefit of PMRT in patients with micrometastatic nodal disease (N1mi) is unknown. We evaluated the survival impact of PMRT in patients with N1mi within the National Cancer Database. METHODS: The pattern of care and survival benefit of PMRT was examined in women with pT1-2N1mi breast cancer who underwent mastectomy without neoadjuvant chemotherapy. Univariable and multivariable Cox proportional hazard models were employed for survival analysis, and subanalyses of high-risk patients and a propensity score-matched (PSM) cohort were completed. RESULTS: From 2004 to 2014, we identified 14,019 patients who fitted the study criteria. PMRT was delivered in 18.5% of patients and its use increased over the study period. Patients treated with PMRT were younger, had better performance status and larger primaries, were estrogen receptor (ER)-negative, had higher grade, lymphovascular invasion and positive surgical margins, and more often received systemic therapy. PMRT was significantly associated with overall survival (OS) in univariable analysis (hazard ratio [HR] 0.75 [0.64-0.89]), but was not significant in multivariable analysis (adjusted HR 1.01 [0.84-1.20]). There was no survival benefit to PMRT in ER-negative, high-grade, and/or young patients. There were 2 (0.9%) death events in the sentinel lymph node biopsy (SLNB) + PMRT group versus 21 (2.9%) in the SLNB-alone group (log-rank p = 0.053), and 8 (3.9%) death events in the axillary lymph node biopsy (ALNB) + PMRT group versus 27 (3.6%) in the axillary lymph node dissection-alone group (p = 0.82). There was no significant association between PMRT and OS within the PSM subgroup. CONCLUSION: In this largest reported retrospective study, no OS differences were associated with PMRT, which suggests that PMRT may not benefit every patient with microscopic nodal disease.
Authors: David Krug; René Baumann; Wilfried Budach; Marciana Nona Duma; Jürgen Dunst; Petra Feyer; Rainer Fietkau; Wulf Haase; Wolfgang Harms; Thomas Hehr; Marc D Piroth; Felix Sedlmayer; Rainer Souchon; Frederik Wenz; Rolf Sauer Journal: Breast Care (Basel) Date: 2020-01-24 Impact factor: 2.860
Authors: Mausam Patel; Chenghui Li; Julia H Aronson; Cole M Howie; Sanjay Maraboyina; Arpan V Prabhu; Thomas Kim Journal: Breast Date: 2020-03-06 Impact factor: 4.380