Capecitabine for adjuvant colon cancer data hits NEJM this week

XACT trial
Twelves et al, NEJM 2005

Patients: Capecitabine 1250mg/m2 (d1-14 q21d) x 8 for 24 weeks (1004 pts) vs Mayo Clinic 5FU 425mg/m2 (d1-5 q28d) x 6 (983 pts)
Followup: 3.8 years
Results: Capecitabine numerically superior to, and statistically not inferior to, the 5FU for DFS. Survival was a little more likely, not to the level of statistical significance, in capecitabine patients.
Toxicity: about half the patients got diarrhea with the capecitabine, less than the conventional 5FU. All toxicities were less with capecitabine, except hand-foot syndrome. 17% of the hand-foot syndrome was grade iii-iv.

Criticisms: the study data was owned by the sponsor, not the researchers. The paper was reviewed by the company prior to submission to the journal. The toxicity data was only reported for 19 months after the enrollment of the last patient, while the median efficacy followup was for 3.8 years.