Abstract: We included four trials, containing 2018 patients. The subjects were mostly white people (female: 26% to 56%), with a median age of 58 to 66 years. About half of them had histologically proven adenocarcinoma. Of the 2018 patients, 83% to 99% had their status measured using the Eastern Cooperative Oncology Group performance status, and had a score of 0 to 1 (which is usually considered as physically "fit"). All four studies provided data on overall survival, progression-free survival, one-year survival rate, objective response rate, and serious adverse events, with two studies (1901 patients) investigating the effect of cetuximab on quality of life as well. The risk of bias was low for the data on overall survival and one-year survival rate, and high for the data on all other outcomes, mainly due to lack of blinding. Compared with chemotherapy alone, chemotherapy plus cetuximab improved overall survival (10.5 months versus 8.9 months; HR 0.87, 95% CI 0.79 to 0.96), one-year survival rate (45% versus 40%; RR 1.13, 95% CI 1.02 to 1.25), and objective response rate (30% versus 23%; RR 1.31, 95% CI 1.14 to 1.51). The difference in progression-free survival was at the limit of the statistical significance (4.9 months versus 4.4 months; HR 0.91, 95% CI 0.83 to 1.00). No significant difference in quality of life between the two treatment arms was reported by the two relevant studies. Patients in the cetuximab group experienced more acneiform rash (11.2% versus 0.3%; RR 37.36, 95% CI 10.66 to 130.95), hypomagnesemia (5.3% versus 0.8%; RR 6.57, 95% CI 1.13 to 38.12), infusion reaction (3.9% versus 1.1%; RR 3.50, 95% CI 1.76 to 6.94), diarrhoea (4.8% versus 2.3%; RR 2.10, 95% CI 1.26 to 3.48), hypokalaemia (6.3% versus 3.6%; RR 1.74, 95% CI 1.02 to 2.99), febrile neutropenia (10.6% versus 7.6%; RR 1.40, 95% CI 1.10 to 1.77), and leukopenia (58.1% versus 42.7%; RR 1.36, 95% CI 1.17 to 1.58) than did those in the control group. The difference in other adverse events did not reach statistical significance. According to the reports of original studies, the adverse events were generally manageable. There were no cetuximab-related deaths. The quality of the evidence is high for overall survival and one-year survival rate, but low for most secondary outcomes. The combination of chemotherapy plus cetuximab is better than chemotherapy alone as the first-line treatment of advanced NSCLC in improving overall survival, while inducing higher rates of some reportedly manageable adverse events.

Plain-language summary: This review of 2018 patients, from four trials, found that adding cetuximab (a newly developed agent) to standard treatment, prolonged the survival time of advanced NSCLC patients by about 1.5 months, and deferred the progression of cancer by about 0.5 month. One year after the treatment, 45% of the patients receiving standard treatment plus cetuximab, and 40% of the patients receiving standard treatment alone were still alive. However, the effects of cetuximab on quality of life of patients were uncertain. Seven types of adverse events, mainly involving skin and blood, occurred much more in the patients receiving cetuximab, while other adverse events seemed to occur equally in both groups. The adverse events were reported as generally manageable. No deaths related to cetuximab were reported. In summary, high quality evidence shows that the use of cetuximab combined with standard treatment leads to better survival than standard treatment alone, in improving survival of patients with advanced NSCLC.