P-276 - S-1 and oxaliplatin (SOx) in older Western patients with metastatic colorectal cancer (mCRC)

Date 04 July 2015
Event WorldGI 2015
Session Posters
Topics Anti-Cancer Agents & Biologic Therapy
Colon Cancer
Rectal Cancer
Presenter S. Winther
Citation Annals of Oncology (2015) 26 (suppl_4): 1-100. 10.1093/annonc/mdv233
Authors S. Winther1, H. Jensen1, P. Pfeiffer1, K. Zubcevic1, S. Amna1, C. Qvortrup1, H. Sorbye2
  • 1Odense University Hospital, Odense/DK
  • 2University of Bergen, Bergen/NO

Abstract

Introduction

Demographic ageing will increase the number of older (70+ years) patients (pts) with mCRC. However, there is limited knowledge about therapy in older cancer pts, as they are underrepresented in clinical trials. In this study we evaluated efficacy and toxicity of S-1 and oxaliplatin (SOx) in older pts not being candidates for standard combination therapy with biologics.

Methods

S-1 is approved for the treatment of advanced gastric adenocarcinoma but in Denmark S-1 may also be used in non-approved indications e.g. pts with mCRC. S-1 is known for a lower incidence of adverse events especially hand-foot syndrome (HFS) compared to capecitabine (Cap). Initially we therefore switched from CapOx to SOx in pts troubled by HFS or GI toxicity but soon we used SOx as initial therapy. Efficacy and toxicity were registered prospectively. All older mCRC pts who have received at least one cycle of SOx were included in this analysis.

Results

From June 2012 to December 2013, 32 older pts received at least 1 cycle of SOx for mCRC. Median age was 76 years (range 70-83 years); 19% had PS 0, 62% PS 1 and 19% PS 2. 11 pts started therapy with CapOx but switched to SOx after one (n = 7) or two (n = 4) cycles due to toxicity (GI toxicity n = 9, HFS n = 2), 21 pts started with SOx. 22 pts completed at least 6 cycles of therapy, 20 pts started with full dose SOx (S-1 25 mg/m2 x 2 po d 1-14 and oxaliplatin 130 mg/m2iv d 1 q 3 weeks). The median relative dose intensities for oxaliplatin and S-1 were 0.80 and 0.85, respectively. The most common toxicity was fatigue (75%) however grade 3 was only observed in 15%. Only one patient (3%) developed febrile neutropenia. Other grade 3/4 non-hematologic toxicities included diarrhea (12%), neuropathy (9%), mucositis (6%), and infection/fever (6%). 13 pts (41%) had PR and 13 pts (41%) had SD resulting in a DCR of 82%. Median PFS was 8.5 (95% CI: 7.2-10.2) months and the median OS was 13.1 (95% CI: 9.6-NR) months. December 1st2014, 14 pts (44%) were alive. 12 pts received second line therapy (S-1 with irinotecan n = 5, FOLFIRI n = 4, Cap n = 1, S-1 n = 2).

Conclusion

SOx is well tolerated and is a promising alternative schedule for older mCRC pts. SOx will be evaluated in the ongoing randomized Nordic9 trial.