Fourteen RCTs (n=2,550) were included in the review.
There was no indication of publication bias (no further results reported). The ELCWP quality scores ranged from 37 to 85 out of a maximum 102.
Overall survival (14 studies).
Maintenance chemotherapy was associated with a statistically significant improved likelihood of overall survival at both 1 year (OR 0.67, 95% CI: 0.56, 0.79, p<0.001) and 2 years (OR 0.67, 95% CI: 0.53, 0.86, p<0.001) compared with no maintenance therapy, based on a fixed-effect model. Similar results were obtained when using a random-effects model. No statistically significant heterogeneity was detected in either analysis (p=0.186 and p=0.018, respectively).
Progression-free survival (8 studies).
Maintenance chemotherapy was associated with a statistically significant improved likelihood of better progression-free survival at both 1 year (OR 0.49, 95% CI: 0.37, 0.63, p<0.001) and 2 years (OR 0.64, 95% CI: 0.45, 0.92, p=0.015) compared with no maintenance therapy, based on a fixed-effect model. When using a random-effects model, similar results were found for 1-year survival but not for 2-year survival: the results for 2-year survival were no longer statistically significant (OR 0.65, 95% CI: 0.39, 1.09, p=0.099). No statistically significant heterogeneity was detected in either analysis (p=0.210 and p=0.099, respectively).
The results of the meta-regression showed that none of the prognostic factors investigated were significantly associated with any of the outcomes. Where available, data for toxicity were also presented.