Five studies (3,293 patients) were included in the review.
Continuous chemotherapy as maintenance therapy compared to control did not show a statistically significant difference in median overall survival, but did increase toxicity, such as nausea and vomiting, neuropathy, asthenia and neutropenia (three RCTs). Only one of the three RCTs reported a statistically significant improvement in progression-free survival (1.6 months, p<0.001, reported as 1.1 months in the text). One RCT reported no statistically significant differences in quality of life.
Switch chemotherapy as maintenance therapy (pemetrexed) compared to placebo showed a statistically significant increase in overall survival (2.8 months, reported as 4.9 months in the text) and in progression-free survival (1.7 months) in patients with non-squamous non-small cell lung cancer (one RCT). Patients who received maintenance treatment reported statistically significant improvements in quality of life in terms of pain only.
No studies that compared continuous molecularly targeted maintenance therapy to observation alone were identified.
One study using erlotinib as switch molecularly targeted therapy as maintenance therapy showed a statistically significant increase in overall survival (one month) and progression-free survival (1.2 weeks) compared to observation alone. There were no statistically significant differences in quality of life, and toxicities were mild to moderate and typical for erlotinib (including diarrhoea and skin rash).
No studies directly compared maintenance therapy after an initial response to first-line therapy versus second-line therapy.