Evaluation of Hematological/Pathological Prognostic Factors and Oncological Outcomes of Patients with Locally Advanced Rectal Cancer Treated with Neoadjuvant Radiotherapy

Abstract

OBJECTIVEIn this study, we aimed to present our results of overall survival (OS), progression-free survival (PFS)and local control (LC) in approximately five years of follow-up of the patients with locally advancedrectal cancer who underwent neoadjuvant radiotherapy (RT) and to investigate both the pathologicaland hematological parameters that affect the survival.METHODSA total of 76 patients with a pathologic diagnosis of rectum adenocarcinoma and clinical stage I- IVAwho underwent neoadjuvant RT between August 2014 and March 2019 were evaluated retrospectivelyin this study. Eighty-five percent of the patients received 45/50 Gy doses of RT concomitantly with oralcapecitabine. Fifty-eight patients (78.4%) underwent surgery. The median time between the completionof RT and surgery was 65 days.RESULTSThe median follow-up was 25 months. The 2-year OS, PFS and LC rates were 85%, 83.7% and 85.2%, respectively. Positive radial surgical margin was a significant prognostic factor for OS and PFS, but not forLC. The factor affecting OS, PFS and LC was adverse tumor histology (undifferentiated). The prolongationof the time from completion of RT to surgery caused OS and LC to deteriorate. Local control significantlydecreased in patients without concomitant chemotherapy. Among all the hematological parameters (e.g.albumin, WBC, platelet, neutrophil, CA 19-9), only pre RT Hb levels significantly correlated with OS butnot with PFS. CEA’s response to neoadjuvant treatment (NAT) significantly increased OS and PFS.CONCLUSIONAdverse tumor histology, the prolonged time from completion of RT to surgery, CEA’s response to NATand pre RT Hb levels were essential factors that affect survival.