Neoadjuvant Chemoradiotherapy and Surgery in Patients Older Than 75 Years Old with Locally Advanced Mid-Low Rectal Cancer

Abstract

This study was designed to evaluate the tolerance and clinical outcomes of neoadjuvant chemoradiotherapy and surgery in patients older than 75 years old with LARC. We reviewed clinical records of patients older than 75 years with LARC treated with neoadjuvant chemoradiotherapy in our institute from January 2013 to May 2017. All patients were treated with intensity-modulated radiotherapy (IMRT). A dose of 45-50Gy in 25 fractions was delivered to the pelvis. The primary tumors received a dose of 55Gy with simultaneous integrated boost (SIB). The concurrent chemotherapy included capecitabine alone and capecitabine plus oxaliplatin (Xelox). Surgery was performed for suitable patients at least 6 weeks after chemoradiotherapy. Adjuvant chemotherapy was performed individualized. Overall survival (OS), disease specific survival (DSS), disease free survival (DFS) and local control (LC) were calculated with Kaplan-Meier method. Univariate and multivariate analyses were performed with log-rank test and cox proportional hazards model. A total of 71 patents were enrolled in this study, the median age was 80 years (range: 75-90 years). All patients completed the neoadjuvant treatment procedure. The median follow-up duration was 31.9 months (range: 4.7-65.1 months), the 3-year OS, DSS, DFS and LC were 75.7%, 86.0%, 72.4% and 83.9%, respectively. The incidences of grade 3 or greater acute hematologic (HM), gastrointestinal (GI) and genitourinary (GU) toxicity were 5.6%, 4.2% and 1.4%, respectively. After neoadjuvant chemoradiotherapy, downstaging was observed in 59 patients (83.1%) including 36 patients (50.7%) with T-downstaging and 48 patients (67.6%) with N-downstaging. Forty-three patients (60.6%) underwent surgery including total mesorectal excision (TME) in 35 patients (81.4%) and transanal endoscopic microsurgery (TEM) in eight patients (18.6%), only two patients (5.7%) experienced surgical complications. For patients receiving definitive surgery (TME), pathological complete response (pCR) was obtained in eight patients (22.9%). Multivariate analysis revealed that only surgery was significantly associated with OS, DSS, DFS, and LC. The 3-year OS, DSS, DFS and LC for patients who received surgery or not were 90.1% vs 48.4% (HR=27.0, 95%CI: 2.6-281.8, P=0.006), 90.1% vs 66.2% (HR=13.3, 95%CI: 1.2-148.8, P=0.036), 83.2% vs 50% (HR=3.0, 95%CI: 1.1-8.4, P=0.037) and 90.6% vs 58.3% (HR=3.8, 95%CI: 1.1-13.1, P=0.034), respectively. In patients with LARC older than 75 years old, neoadjuvant chemoradiotherapy was well tolerated with excellent clinical outcomes. Surgery was a significant factor for OS, DSS, DFS, and LC with acceptable complications, which should be strongly suggested for this group of patients.