Combination chemotherapy according to tumor histology in non-small cell lung cancer

This study analyzed the efficacy and safety of a combination of carboplatin and S-1 in the treatment of advanced non-small cell lung cancer (NSCLC).

NSCLC accounts for 85% of lung cancers, and appears in two distinct histological subtypes; squamous cell carcinoma and non-squamous cell carcinoma. Histological subtypes are based on differences in the microscopic appearance of the tissue. While the chemotherapy combination of carboplatin and paclitaxel is considered the standard of care in the treatment of NSCLC, a recent trial has shown carboplatin and S-1, a relatively new oral chemotherapy agent, to be equally effective among some patients. The current study analyzed the effectivity of carboplatin and S-1 according to histological cancer subtypes.

A total of 564 patients with advanced stage lung cancer, 114 with squamous cell carcinoma and 450 with non-squamous cell carcinoma, were evaluated in this study. Patients were randomly assigned to receive either carboplatin with paclitaxel or carboplatin and S-1.

The average overall-survival was 15.2 months for patients treated with carboplatin and S-1, and 13.1 months for those treated with carboplatin and paclitaxel. However, this difference was not found to be statistically significant on further analysis. When analyzing results according to tumor histology, squamous cell carcinoma patients receiving carboplatin and S-1, experienced an average overall survival of 14 months, compared to 10.6 months among those treated with carboplatin and paclitaxel. This correlated to a significant reduction of 28% in the risk of mortality among squamous cell carcinoma patients receiving carboplatin and S-1. Among non-squamous cell carcinoma patients receiving carboplatin and S-1, an average overall survival of 15.5 months was noted, compared to 13.9 months among patients being treated with carboplatin and paclitaxel. However, this difference was not found to be statistically significant on further analysis.

Regardless of histology, carboplatin and S-1 was associated with a higher rate of severe thrombocytopenia (a low platelet count increasing the risk of bleeding), but a lower rate of neutropenia (a low white blood cell count increasing the risk of serious infection).

This study concluded that carboplatin and S-1 is an effective chemotherapy combination in the treatment of non-small cell lung cancer, regardless of tumor histology. Specifically among squamous cell carcinoma patients, carboplatin and S-1 appears to be superior to the standard carboplatin and paclitaxel combination.