Background: Metastatic colorectal cancer (mCRC) frequently occurs in elderly patients. However, data from a geriatric tailored randomized trial about tolerance to and the efficacy of doublet chemotherapy (CT) with irinotecan in the elderly are lacking. The benefit of first-line CT intensification remains an issue in elderly patients.
Patients and methods: Elderly patients (75+) with previously untreated mCRC were randomly assigned in a 2 × 2 factorial design (four arms) to receive 5-FU (5-fluorouracil)-based CT, either alone (FU: LV5FU2 or simplified LV5FU2) or in combination with irinotecan [IRI: LV5FU2-irinotecan or simplified LV5FU2-irinotecan (FOLFIRI)]. The CLASSIC arm was defined as LV5FU2 or LV5FU2-irinotecan and the SIMPLIFIED arm as simplified LV5FU2 or FOLFIRI. The primary end point was progression-free survival (PFS). Secondary end points were overall survival (OS), safety and objective response rate (ORR).
Results: From June 2003 to May 2010, 71 patients were randomly assigned to LV5FU2, 71 to simplified LV5FU2, 70 to LV5FU2-irinotecan and 70 to FOLFIRI. The median age was 80 years (range 75-92 years). No significant difference was observed for the median PFS: FU 5.2 months versus IRI 7.3 months, hazard ratio (HR) = 0.84 (0.66-1.07), P = 0.15 and CLASSIC 6.5 months versus SIMPLIFIED 6.0 months, HR = 0.85 (0.67-1.09), P = 0.19. The ORR was superior in IRI (P = 0.0003): FU 21.1% versus IRI 41.7% and in CLASSIC (P = 0.04): CLASSIC 37.1% versus SIMPLIFIED 25.6%. Median OS was 14.2 months in FU versus 13.3 months in IRI, HR = 0.96 (0.75-1.24) and 15.2 months in CLASSIC versus 11.4 months in SIMPLIFIED, HR = 0.71 (0.55-0.92). More patients presented grade 3-4 toxicities in IRI (52.2% versus 76.3%).
Conclusion: In this elderly population, adding irinotecan to an infusional 5-FU-based CT did not significantly increase either PFS or OS. Classic LV5FU2 was associated with an improved OS compared with simplified LV5FU2.
Clinicaltrialsgov: NCT00303771.
Keywords: chemotherapy; colorectal cancer; elderly; geriatric oncology.
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