Impact of contemporary therapy- concepts on surgical morbidity in breast cancer patients: A retrospective single center analysis of 829 patients.

INTRODUCTION Morbidity after breast cancer surgery remains low with revision surgery below 5%. This retrospective monocentric study investigates whether new methods like neoadjuvant chemotherapy (nCT), oncoplastic surgery (OPS) or intraoperative radiotherapy (IORT) affect overall morbidity. In addition, we sought to determine a possible effect of morbidity on oncologic outcome. METHODS Clinical Data from all breast cancer cases, operated at the OnkoZert"- certified Breast Health Center of the "Sisters of Charity Hospital" in Linz between 2011 and 2014, were evaluated. Age (≤/>70), nCT, IORT, surgical technique and histological subtypes were analyzed concerning their impact on morbidity. Overall survival (OS) and disease-free survival (DFS) were assessed by Kaplan-Meier estimates. RESULTS 829 patients were included, 24% were older than 70y, 19% underwent oncoplasty, 5.5% immediate reconstruction, 17% of the invasive cancers were treated with nCT and 4.1% received IORT. One or more complications occurred in 83 patients (10%), while 62 patients (7.5%) underwent revision surgery. Univariate analysis showed that mastectomy and age >70 doubled the risk of surgical morbidity. Multivariate regression analysis identified age >70 as the only independent prognostic parameter for the occurrence of morbidity (OR: 2.42, 95% CI: 1.41-4.1, p = 0,00134). Morbidity was not associated with worse oncologic outcome in terms of OS or DFS. SUMMARY In our patient collective, modern techniques such as nCT, OPS or IORT did not influence surgical morbidity rates. Those were only increased by patient's age. Additionally, surgical morbidity did not show any significant impact on OS and DFS.