Efficacy and safety of FOLFIRI regimen in elderly versus nonelderly patients with advanced colorectal and gastric cancer.

Abstract

701 Background: Irinotecan-based chemotherapy is a standard backbone in patients (pts) with advanced colorectal (CRC) or gastric cancer (GC). However, there is still a paucity of information concerning the efficacy and safety of irinotecan-based regimen in elderly pts. Methods: Using pt cohort (N = 1,545) of the UGT1A1 genotype study (Kim KP, et al. J Clin Oncol 33, 2015 (suppl; abstr 3600)), we performed subgroup analysis comparing the efficacy and safety between elderly (age ≥ 70 years, median 73 years, N = 245) and non-elderly ( < 70 years, median 57 years, N = 1,300) pts with advanced CRC or GC who received first- or second-line FOLFIRI chemotherapy. Results: In both CRC (N = 934) and GC cohorts (N = 611), elderly pts received significantly lower dose of irinotecan (CRC: mean 74.8% vs. 80.9%, P < 0.001; GC: 72.4% vs. 76.2%, P = 0.018) and infusional 5-fluorouracil (CRC: 61.6% vs. 71.8%, P < 0.001; GC: 47.1% vs. 55.8%, P = 0.004). However, the response rate was similar between elderly and non-elderly pts in both CRC (28.7% vs. 32.9%, P = 0.347) and GC cohorts (22.9% vs. 18.3%; P = 0.369). The progression-free survival was also similar between the two age groups in both CRC (median 27.9 vs. 29.1 weeks, P = 0.202) and GC cohorts (20.1 vs. 17.0 weeks, P = 0.407). In addition, the overall survival was comparable between the two age groups in both CRC (81.9 vs. 91.8 weeks, P = 0.965) and GC cohorts (33.6 vs. 49.3 weeks, P = 0.085). In both cohorts, asthenia was significantly more frequent in elderly pts, while nausea and vomiting were significantly more frequent in non-elderly pts. In CRC cohort, grade 3-4 toxicities that were significantly more frequent in elderly pts were asthenia (1.3% vs. 0.2% per cycle, P < 0.001), mucositis (0.4% vs. 0.1%, P = 0.021), and anorexia (0.8% vs. 0.2%, P = 0.005) in CRC cohort. However, in GC cohort, grade 3-4 toxicities were not significantly different between the two age groups. Conclusions: Despite relatively lower dose intensity in elderly pts, efficacy of FOLFIRI regimen in this subset was comparable to that of non-elderly pts. FOLFIRI regimen was relatively well tolerated in elderly pts. Taken together, FOLFIRI is a considerable standard backbone in elderly pts with advanced CRC or GC.