Prognostic value of morphological characteristics assessed by CT scan in patients with non-small cell lung cancer treated with nivolumab.

Background: Nivolumab is known to demonstrate superior overall survival compared with docetaxel in pretreated non-small cell lung cancer (NSCLC) patients. Programmed death-ligand 1 (PD-L1) expression is reported to predict the outcome of treatment by nivolumab in lung cancer patients. However, the significance of the morphological characteristics of chest computed tomography (CT) as predictors of nivolumab efficacy for advanced NSCLC patients remains unknown.

Methods: We performed a multicenter retrospective trial from April 2013 to March 2017, to assess the significance of CT morphological characteristics as predictors of nivolumab efficacy for advanced NSCLC patients. A total of 78 NSCLC patients pretreated with nivolumab were enrolled. A chest radiologist used chest CT to assess the following morphological characteristics of each patient's main tumor and intrathoracic status prior to nivolumab treatment; interstitial septal thickening, peritumoral ground-glass opacity, spiculated margin, air bronchogram, cavity or necrosis, adjacent organ invasion, bulky lymph node, and accumulation of small lymph nodes. Logistic regression and Cox proportional hazards regression models were used to analyze outcomes.

Results: A total of 60 (77%) patients were male and 72 (92%) had a performance status (PS) of 0 or 1. The objective response rates of male patients and heavy smokers were significantly higher than those of female patients and light or never smokers, respectively. Multivariate analysis identified light or never smoking, poor PS, histological type of squamous cell carcinoma, and interstitial septal thickening as independent negative predictors of progression free survival (PFS).

Conclusions: Interstitial septal thickening was a significant and independent predictor of PFS in NSCLC patients treated with nivolumab.

Key Points: SIGNIFICANT FINDINGS OF THE STUDY: Interstitial septal thickening is an independent predictor of progression free survival in non-small lung cancer patients treated with nivolumab.

What This Study Adds: The current study reveals the significance of morphological characteristics obtained via chest computed tomography as a predictor of nivolumab efficacy for advanced non-small cell lung cancer patients.