Purpose: 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.
Patients and methods: 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.
Results: 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.
Conclusion: 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.