P-259 - Recurrence-free survival according to treatment modality among elderly stage III colon cancer patients

Date 04 July 2015
Event WorldGI 2015
Session Posters
Topics Geriatric Oncology
Colon Cancer
Presenter F. van Erning
Citation Annals of Oncology (2015) 26 (suppl_4): 1-100. 10.1093/annonc/mdv233
Authors F. van Erning1, M. Janssen-Heijnen2, G.-. Creemers3, V. Lemmens1, H. Pruijt4
  • 1Netherlands Comprehensive Cancer Organisation, Eindhoven/NL
  • 2VieCuri Medical Centre, Venlo/NL
  • 3Catharina Hospital, Eindhoven/NL
  • 4Jeroen Bosch Hospital, Den Bosch/NL

Abstract

Introduction

Little is known about the effect of specific adjuvant chemotherapy (adjCT) regimens on recurrence-free survival (RFS) among elderly stage III colon cancer patients treated in clinical practice.

Methods

Stage III colon cancer patients aged ≥70 years diagnosed in southern-Netherlands between 2005-2012 who underwent surgery only or who received adjCT, comprising of capecitabine and oxaliplatin (CAPOX) or capecitabine monotherapy (CapMono), were included. Crude 5-year RFS was calculated using Kaplan-Meier curves and Log-Rank tests. RFS was defined as the time from surgery to recurrence or death, whichever occurred first, or last follow-up date for patients without recurrence or death. Multivariable Cox regression analyses were used to discriminate independent risk factors for adverse outcome. Variables included were gender, age, comorbidity, ASA score, pT-pN stage, tumour subsite, differentiation grade, period of diagnosis and treatment modality. To overcome the effect of postoperative mortality on long-term survival, landmark analyses were used; only patients who survived the first 90 days after surgery were included in the survival analyses.

Results

Overall, 749 patients underwent surgery only, 193 patients received CAPOX and 164 patients received CapMono. Crude 5-year RFS was 38% for patients undergoing surgery only as compared to 60% for patients receiving CAPOX (p < 0.0001). For patients receiving CapMono Crude 5-year RFS was 63% and this did not differ from patients receiving CAPOX (p = 0.911). Also after casemix adjustment, the risk for recurrence or death was higher for patients undergoing surgery only as compared to patients receiving CAPOX (HR 2.07, 95% CI 1.51-2.83). The risk for recurrence or death was not different for patients receiving CapMono as compared to CAPOX (HR 0.99, 95% CI 0.68-1.44).

In subgroup analysis, among patients receiving adjCT and completing all planned cycles, crude RFS after 56 months (n < 10 after this time for CAPOX) was 69% for CAPOX (n = 63) and 69% for CapMono (n = 90) (p = 0.758). Among patients not completing all planned cycles, crude RFS after 56 months was 56% for CAPOX (n = 129) and 54% for CapMono (n = 74) (p = 0.538). In multivariable analysis, the risk for recurrence or death was equal for patients completing all planned cycles of CapMono as compared to patients completing all planned cycles of CAPOX (HR 1.28, 95% CI 0.64-2.56). For patients who did not complete all planned cycles of CAPOX or CapMono, the risk of recurrence or death was higher as compared to patients completing all planned cycles of CAPOX (HR 1.97, 95% CI 1.08-3.61 and HR 2.17, 95% CI 1.07-4.41 respectively).

Conclusion

Among elderly stage III colon cancer patients, receipt of CAPOX or CapMono is associated with improved RFS. The improvement differs according to completion of all planned cycles but not by regimen.