Neoadjuvant chemoradiotherapy with capecitabine in locally advanced rectal cancer: Analysis of prognostic factors.

Abstract

92 Background: Capecitabine-based neoadjuvant chemoradiotherapy is the standard treatment for locally advanced rectal cancer (LARC). The objective of this retrospective study is to analyze overall survival (OS), local relapse free-survival (LRFS), distant metastases free-survival (DMFS) and prognostic factors. Methods: Between 2009 and 2018, 207 patients(p) with LARC has been treated in our hospital with neoadjuvant CRT. Clinical characteristics: Mean age: 65 y (41-87); male:129, female:78; TNM: cT2: 12p, cT3: 176p, cT4: 19p, cN0: 59p, cN1: 106p, cN2: 42p. Treatment: pelvic radiotherapy (45Gy, 1.8Gy/day) plus concomitant capecitabine (852mg/sqm/12h for 28 days). Surgery (mesorectal excision) was carried out 6-8 after the end of CRT. Statistics:Kaplan-Meier and Log-rank test. Results: Mean follow-up: 43 months. Downstaging:104/192 (54%). Pathological complete response:31/192 (16%). Sphincter preservation rate was 82%. Five-year OS, LRFS and DMFS were 89.9%, 93.3% and 81.7%, respectively. Factors predicting shorter 5-y OS were: cT4 (69% vs 91% and 91% for cT1 and CT2, respectively; p=0.027), pT3-4 (85% and 64% vs 100%, 100% and 98% for pT0, pT1 and pT2, respectively; p=0.008), pathological involved nodes (pN+) (77% vs 96%; p=0.001), perineural invasion (PNI) (78% vs 95%; p=0.041), LVI (p<0.001), Ryan 3 (p<0.001), resection margin R1 (67% vs 94% for R0; p<0.001), no pCR (p=0.027) and absence of downstaging (73% vs 97%; p=0.001). Factors associated with poor 5-y DMFS were:pT3-4 ( 70% and 0% vs 96%,88% and 98% for pT0,pT1 and pT2, respectively; p<0.001), pN+ (68% vs 88% for pN0: p<0.001), PNI (64% vs 85%; p=0.036), Ryan 3 (49% vs 96%, 85% and 85% for Ryan 0, 1 and 2, respectively; p<0.001), R1 (33% vs 86% for R0; p<0.001) and absence of downstaging (50% vs 71%; p<0.001). CTCAE 4.0 grade 3 toxicity: 1%. No grade 4 toxicity was seen. Conclusions: CRT with capecitabine provides high rates of survival and sphinter preservation with excellent tolerance. Patients with adverse pathological factors (pT4, pN+, PNI, Ryan 3, R1 and absence of downstaging) have a higher risk of distant metastasis and are more likely to benefit from adjuvant chemotherapy.