Multicenter phase II trial of S-1 as first-line treatment in elderly patients with metastatic or recurrent unresectable colorectal cancer

Abstract

15057 Background: This study was conducted to evaluate the efficacy and safety of S-1 monotherapy as first-line treatment in elderly patients with metastatic or recurrent colorectal cancer (CRC). Methods: Patients with CRC who were either age 65–69 years with ECOG 2 or 70–85 years of age with ECOG 0–2 were eligible. S-1 was administered in 35mg/m2 twice daily for 2 weeks followed by 1 week rest period (one cycle). Results: Thirty-three patients with the median age of 73 years (range, 66 - 84 years) entered the current study and six (18.2%) patients had ECOG performance status 2. S-1 produced an objective response rate of 21.2% (seven partial responses) and stable disease in 14 patients (42.4%). The median times to progression was 4.0 months (95% CI, 2.9 to 6.1 months) but the median overall survival was not reached until now. S-1 demonstrated a favorable safety profile, with no treatment-related grade 4 adverse events and deaths. Grade 3 anemia, neutropenia and thrombocytopenia were observed in 6.1%, 3.0% and 3.0% of patients, respectively. The most frequent adverse events were diarrhea (grade 3, 12.1%) and grade 3 hand-foot syndrome was observed in only one patient (3.0%). Conclusions: S-1 monotherapy appears to be an effective and safe option in elderly patients who had metastatic or recurrent CRC. In addition, promising results indicate further trials with combination of S-1 with oxaliplatin or irinotecan required, which may prove to be more effective. No significant financial relationships to disclose.