Adjuvant chemotherapy based on the in vitro histoculture drug response assay for non-small cell lung cancer improves survival

Abstract

Background: In this study, we analyzed the usefulness of adjuvant chemotherapy for non-small cell lung cancer based on the histoculture drug response assay (HDRA). Methods: From September 2001 to December 2008, 65 patients with pathologic stage II or higher non-small cell lung cancer who underwent surgery received two-cycle HDRA-based adjuvant chemotherapy. Chemosensitivity to cisplatin, carboplatin, paclitaxel, docetaxel, gemcitabine, and irinotecan was examined by the HDRA. All patients were classified according to the number of administered HDRA-positive drugs: the prediction-sensitive group (PSG) (n = 31) comprised patients treated with two HDRA-positive drugs and the prediction-nonsensitive group (PNSG) (n = 34) comprised those treated with a combination of one HDRA-positive and one HDRA-negative drug or two HDRA-negative drugs. The clinical outcomes of the two groups were analyzed. Results: The overall 5-year survival rate of the PSG was 82.4%. On the other hand, that of the PNSG was 40.1%. There were significant differences between the two groups (p = 0.03). The 5-year disease-free survival rate was more favorable in the PSG than in the PNSG (PSG: 56.5%, PNSG: 30.1%, p = 0.05). Multivariate analysis showed that chemotherapy based on the HDRA was a significant prognostic factor (p = 0.03). Conclusions: The prognosis of patients treated with two HDRA-positive drugs was significantly better than that of those treated with one HDRA-positive drug or HDRA-negative drugs. Adjuvant chemotherapy based on the in vitro HDRA may be useful to improve survival in patients who have undergone surgery. © 2010 by the International Association for the Study of Lung Cancer.