Computed tomography response, but not positron emission tomography scan response, predicts survival after neoadjuvant chemotherapy for resectable non-small-cell lung cancer.

Abstract

Tumor response is considered a surrogate marker of survival. We investigated whether tumor response based on computed tomography (CT) scan or whole-body [(18)F]fluorodeoxyglucose positron emission tomography (PET) scan after neoadjuvant chemotherapy for resectable non-small-cell lung cancer (NSCLC) is prognostic of survival. Two consecutive phase II clinical trials were jointly analyzed. Patients underwent CT and PET scans before and after completion of neoadjuvant chemotherapy, followed by surgery. Eighty-nine patients were included. Patients with a partial or complete response based on Response Evaluation Criteria in Solid Tumors categories (n = 33) had a better overall survival than those with stable or progressive disease (n = 56; median survival time, not reached v 36 months, respectively; P = .04). Of all patients, those with response in the highest quartile had 1- and 2-year survival rates of 100% and 81%, respectively, compared with 77% and 61%, respectively, among patients in the lowest quartile. However, on the basis of visual analysis of PET scan, patients with a metabolic response (n = 28) had no significant difference in survival compared with patients without response (n = 61; median survival time, 35.6 months v not reached, respectively; P = .94). In addition, on the basis of a semiquantitative analysis of PET scan, using at least 30% reduction in tumor metabolism as a response (n = 59), we also found no significant difference in survival among those with or without response. Among patients with resectable NSCLC treated with neoadjuvant chemotherapy, we found no evidence that tumor response by PET scan after chemotherapy is prognostic of survival; however, response by CT scan was associated with better survival.