Five RCTs (n=1,005) were included in the review. There was some overlap between two studies. Excluding the smaller of the overlapping studies gave n=916. Sample sizes ranged between 15 and 205 patients.
Significantly higher complete remission rates were reported with CHOP compared with CNOP for the two meta-analysis that excluded each overlapping study in turn, CHOP odds ratio 0.55 (95% confidence interval: 0.42, 0.72, p=0.000005) and CNOP odds ratio 0.50 (95% confidence interval: 0.37, 0.68, p=0.000005). There was no significant difference between CNOP and CHOP for overall survival.
No formal testing of side effects could be undertaken, but both regimens were equally myelosuppressive. The incidence of alopecia (four studies) and gastrointestinal toxicities (three studies) were reported to be more frequent in CHOP patients compared to CNOP patients. Three of four studies reported no difference in cardiotoxicity; one study reported significantly more patients with a non-symptomatic reduction in left ventricular ejection fraction in the CHOP compared to CNOP group (CHOP 40 per cent and CNOP seven per cent, p<0.039). Values for results data were generally not reported in the paper.