Efficacy of 5-fluorouracil-based chemotherapy in elderly patients with metastatic colorectal cancer:: a pooled analysis of clinical trials

Background: Recently published population-based investigations showed elderly patients to be underrepresented in clinical trials and less often treated according to the standard therapy. Although there is evidence that elderly patients benefit from adjuvant (radio-) chemotherapy to the same extent as younger patients, no large series describes the influence of age on efficacy of chemotherapy in metastatic colorectal cancer. Patients and methods: We carried out a retrospective analysis using source data of 3825 patients who received 5-fluorouracil (5-FU)-containing treatment in 22 European trials and identified 629 patients with an age of greater than or equal to70 years. Results: We found an equal overall survival in elderly patients [10.8 months, 95% confidence interval (0) 9.7-11.8] and in younger patients (11.3 months, 95% CI 10.9-11.7; P=0.31). Response rate did not differ between age groups greater than or equal to70 and <70 years (23.9% and 21.1%; respectively; P=0.14). Progression-free survival was marginally prolonged in elderly patients (5.5 months, 95% Cl 5.2-5.8; compared with 5.3 months, 95% CI 5.1-5.5; P=0.01). In both age groups, infusional 5-FU resulted in significantly increased response rates, overall survival and progression-free survival compared with bolus 5-FU. Conclusions: 'Fit' elderly patients benefit at least to the same extent from palliative chemotherapy with 5-FU as younger patients. Infusional 5-FU was shown to be more effective than bolus 5-FU in both age groups. Therefore, standardized palliative chemotherapy should generally be offered to elderly patients and they should not be excluded from clinical trials.