Postmastectomy Radiotherapy Decision for Patients without Lymph Node Metastases: Turkish Radiation Oncology Society Breast Cancer Working Group

Abstract

OBJECTIVERecent meta-analysis have not revealed any positive effects of postmastectomy radiotherapy (PMRT)on locoregional recurrence (LRR) or overall survival in axilla-negative patients. However, risk of LRRincreases to 15% in the presence of two or more adverse factors for the same patient group. In this study,PMRT indications and volume selections of radiation oncologists in Turkey for axilla-negative breastcancer was investigated.METHODSQuestionnaires were distributed to members of the breast cancer study group. Data of patients with axillary negative or isolated/micrometastasis and PMRT over 10 years (2006–2016) were collected from 10participating centers. Clinical and tumor histopathological features and treatment details of 185 patientswere analyzed.RESULTSThe median age of patients was 48 years. Ratio of early-stage patients was 60% (T1-15%,T2-45%). Therewere 147 (79%) negative cases, 32 (17%) with micrometastasis, and 6 (3%) with isolated tumor cells.Half of the patients had only their chest walls (CW) irradiated. Peripheral lymphatics were also includedin the rest. In Nmic cases, ratio of irradiation of supraclavicular and axillary lymph nodes with CW werestatistically significant compared to CW irradiation (72% and 28%, respectively; p=0.015).CONCLUSIONConsidering the low number of patients treated over 10 years in 10 different centers in Turkey, it can besaid that PMRT is often done in node-negative breast cancer. It is difficult to reach a definite conclusionfor patients with Nmic, due to lack of data from patients with PMRT. However, the general tendency isto irradiate peripheral lymphatics in Nmic cases if PMRT is to be performed.