221P - A negative prognosis of radiotherapy-induced lower lymphocyte to monocyte ratio in patients with breast cancer

Abstract

BackgroundA decrease lymphocyte to monocyte ratio (LMR) has been reported to be related with worsen prognosis for certain hematologic and solid malignancies. Also pretreatment LMR is associated with the prognosis of patients with breast cancer. However, relationship between treatment-related low LMR and prognostic impact has not well been investigated in breast cancer. The purpose of this study is to evaluate the relationship between radiotherapy (RT)-induced low LMR and recurrence in patients with breast cancer. MethodsWe retrospectively reviewed 1,735 patients with stage I to III breast cancer treated with breast conserving surgery (BCS) and adjuvant RT at Gangnam Severance Hospital and Severance Hospital from January 2006 to 2016 December. The values of LMR were calculated at baseline (A1), before the first RT administration (A2) and before the last RT administration (A3). The reference point of RT-induced low LMR was defined as≤2.6 used in other studies. The recurrence-free survival (RFS) was compared according to RT-induced LMR. ResultsWe retrospectively reviewed 1,735 patients with stage I to III breast cancer treated with breast conserving surgery (BCS) and adjuvant RT at Gangnam Severance Hospital and Severance Hospital from January 2006 to 2016 December. The values of LMR were calculated at baseline (A1), before the first RT administration (A2) and before the last RT administration (A3). The reference point of RT-induced low LMR was defined as≤2.6 used in other studies. The recurrence-free survival (RFS) was compared according to RT-induced LMR. ConclusionsWe demonstrated that RT-induced low LMR is a poor prognostic factor for patients with BCS and adjuvant RT. Legal entity responsible for the studyThe authors. FundingHas not received any funding. DisclosureAll authors have declared no conflicts of interest.