Adenosine triphosphate-based chemotherapy response assay (ATP-CRA)-guided platinum-based 2-drug chemotherapy for unresectable nonsmall-cell lung cancer

BACKGROUND: The study investigated correlations between adenosine triphosphate / chemotherapy response assay (ATP-CRA) and clinical outcomes after ATP-CRA-guided platinum-based chemotherapy for unresectable nonsmall-cell lung cancer (NSCLC). METHODS: The authors performed an in vitro chemosensitivity test, ATP-CRA, to evaluate the chemosensitivities of anticancer drugs such as cisplatin, carboplatin, paclitaxel, docetaxel, gemcitabine, and vinorelbine for chemonaive, unresectable NSCLC. The cell death rate was determined by measuring the intracellular ATP levels of drug-exposed cells compared with untreated controls. A sensitive drug was defined as a drug producing 30% or more reduction in ATP compared with untreated controls. Assay-guided platinum-based 2-drug chemotherapy was given to patients with pathologically confirmed NSCLC. RESULTS: Thirty-four patients were enrolled. Thirty tumor specimens were obtained by bronchoscopic biopsies and 4 obtained surgically. The median age was 61 years and 27 patients had an Eastern Cooperative Oncology Group (ECOG) performance status of 0-1. The response rate was 43.8%. At a median follow-up period of 16.9 months, the median progression-free and overall survivals were 3.6 and 11.2 months, respectively. Patients were dichotomized into the platinum-sensitive (S; 20 patients) and resistant (R; 14 patients) groups. The positive/negative predictive values were 61.1% and 78.6% with a predictive accuracy of 68.8%. Although without significant differences in pretreatment parameters, the S-group showed better clinical response (P=.036), longer progression-free survival (P=.060), and longer overall survival (P=.025). CONCLUSIONS: Despite using bronchoscopic biopsied specimens, ATP-CRA and clinical outcomes correlated well after assay-guided platinum-based 2-drug chemotherapy for unresectable NSCLC. There was a favorable response and survival in the platinum-sensitive vs resistant groups.