Patients suffering from metastatic colorectal cancer survive longer when treated with irinotecan combined with fluorouracil and calcium folinate compared with those treated with fluorouracil and folinate only, say Dr Jean-Yves Douillard (Centre René Gauducheau, St Herblain, France) and colleagues.
Reporting in the Lancet (2000;355:1041), Dr Douillard et al say that weekly or two weekly regimens of fluorouracil, calcium folinate and irinotecan bring "clear clinical benefit" and should be considered as first-line treatment for the disease.
In a phase III trial, the researchers gave 199 patients irinotecan in addition to fluorouracil and calcium folinate, and 188 patients fluorouracil and calcium folinate alone and assessed the response rate. In the evaluable population, the response rate was 49 per cent in the irinotecan group and 31 per cent in the no-irinotecan group. In the intention-to-treat population, these figures were 35 per cent and 22 per cent, respectively, they say. The median time to the onset of response for the irinotecan group was 8.9 weeks and 11.4 weeks in the no-irinotecan group. In addition, they found that median survival in the irinotecan group was 17.4 months compared with 14.1 months in the no-irinotecan group. The authors say that diarrhoea and neutropenia were the most common side effects experienced by the trial subjects but that they were significantly more severe and frequent in the irinotecan group. However, this did not affect the median duration of treatment. When patients were asked to assess their quality of life, the irinotecan group noted a definitive deterioration consistently later than those in the no-irinotecan group, say the authors.
Irinotecan inactivates topoisomerase I and thus inhibits cell division.