Cancer Research Lab

Following treatment of 5-fluorouracil (5FU) refractory metastatic colorectal cancer with oxaliplatin and irinotecan, survival is greater in patients under the age of 70 years, according to Australian researchers.

In the February issue of the British Journal of Cancer, Dr. Niall C. Tebbutt of Austin Hospital, Heidelberg and colleagues conducted an Australian population-based study using a government insurance database covering 2002 and 2003 and involving almost 3000 patients.

In 2002, the team found that 48% of patients received initial treatment with oxaliplatin rather than irinotecan. However, 66% started with oxaliplatin in 2003, a significant increase.

In total, 40% to 45% of patients received treatment with both drugs. This was significantly more likely to be true of younger patients and survival was greater in this group.

Approximately 67% of F-5U refractory patients were estimated to survive for 6 months. The corresponding proportion at 1 year was 42%.

These survival findings were lower than those seen in clinical trials, where about 80% of subjects were alive at 6 months and more than 50% were alive at 1 year.

Nevertheless, the investigators point out that overall survival was similar, and that the difference may have been due to trial subjects being younger and fitter.

However, in clear contrast to clinical trial results, there was a higher survival in younger patients regardless of the type of initial treatment. This, the investigators conclude, may be “because clinicians treat older patients less intensively.”