Baseline SUVmax at PET-CT in Stage IIIA Non-small-cell Lung Cancer Patients Undergoing Surgery after Neoadjuvant Therapy: Prognostic Implication Focused on Histopathologic Subtypes

Abstract

To evaluate the prognostic significance of maximum standardized uptake value (SUVmax) at (18)F-fluorodeoxyglucose (FDG) positron emission tomography-computed tomography in patients with stage IIIA non-small-cell lung cancer (NSCLC) who underwent surgical resection after neoadjuvant chemoradiotherapy, focused on the relationship between SUVmax values and tumor histology. We retrospectively evaluated the initial SUVmax of 205 patients (112 adenocarcinomas, 82 squamous cell carcinomas [SCCs], and 11 of other histology) with a stage IIIA NSCLC who underwent surgical resection after neoadjuvant chemoradiotherapy, and who were followed for up to 6 years. Clinical data, including histologic type, pathologic response, and treatment, were reviewed, and the relationship between the SUVmax and patient overall survival was examined. Overall, the 2-year survival rate was 68%. Between the two histologic subtypes of adenocarcinoma and SCC, we noted significant differences in all variables of gender (male predominance in SCC), initial SUVmax (greater in SCC), pathologic response (more complete remission in SCC), and overall survival (better in SCC) (all P values, < .05). SUVmax remained as a sole independent factor for survival in multivariate analysis in whole series (SUVmax cutoff, 13; median survival, 3.0 years vs. 4.0 years; P = .016) and in adenocarcinomas (SUVmax cutoff, 11.5; median survival, 2.6 years vs. 3.6 years; P = .045), but not in SCCs. The initial SUVmax is a sole significant prognostic factor in patients with a surgically resected NSCLC after neoadjuvant chemoradiotherapy, particularly in patients with an adenocarcinoma.