Six RCTs (n=1,262) were included.
Most of the RCTs were of poor to average quality. Only one used centralised concealed random allocation and only two met more than half of the nine quality criteria. Baseline prognostic factors differed between the groups in four of the studies, for example with respect to cancer staging and location.
Mortality.
The pooled analysis showed that cancer-related mortality was significantly lower in the laparoscopy group than in the group having open resection (OR 0.67, 95% CI: 0.48, 0.94; 4 RCTS, n=1,194). The NNT for this outcome was 23 (or 21 after the sensitivity analysis excluding studies involving rectal disease). For all-cause mortality there was no statistically significant difference between the groups (OR 0.76, 95% CI: 0.52, 1.11; 4 RCTS, n=1,194).
Recurrence.
The pooled analysis showed no statistically significant differences between the groups for all recurrences or port-side recurrence, but local recurrences were significantly lower in the laparoscopy group than in the group having open surgery (OR 0.39, 95% CI: 0.17, 0.89; 5 RCTs, n=388).
Morbidity (6 RCTs, n=1,262).
The pooled analysis showed no significant difference between the groups in terms of morbidity (various definitions used across the trials); there was evidence of statistically significant heterogeneity.
The results of the sensitivity analysis, which excluded studies involving rectal disease, did not change the significance of any of the findings. The funnel plots did not show any evidence of publication bias. The review reported further data.