The benefits of chemotherapy in patient subgroups with unresectable non-small-cell lung cancer

Background: Cisplatin-based chemotherapy improves survival in advanced non-small-cell lung cancer. Using data from phase III trials of mitomycin, ifosfamide and cisplatin, this paper investigates whether the beneficial effect of chemotherapy on survival and quality of life seen overall is limited to certain patient subgroups. Patients and methods: The survival benefit of chemotherapy was compared with standard treatment using hazard ratios for subgroups specified by stage, sex, age, histology and performance status (PS). The effect on quality of life was investigated for three subgroups defined by performance status. Results: The overall unstratified hazard ratio for all 797 eligible patients shows a 16% reduction in the risk of death with chemotherapy (P = 0.02). This benefit was seen for both locally advanced and extensive stage disease (significantly in extensive disease). Subgroups defined by sex, age and histology consistently benefitted from chemotherapy. The hazard ratios for the three levels of performance status suggest that PS2 patients gain no survival benefit from chemotherapy. In contrast, these patients experienced the greatest improvement in quality of life during the first six weeks of chemotherapy. Conclusions: Subgroup analysis suggests that the prolongation of life from cisplatin-based chemotherapy is confined to PS0/1 patients. Palliation is greater in PS2 patients.