Predictive model of the first failure pattern in patients receiving definitive chemoradiotherapy for inoperable locally advanced non-small cell lung cancer (LA-NSCLC)

Xueru Zhu,Wuyan Xia,Runping Hou,Chang Jiang,Xiaolong Fu,Xiaoyang Li

doi:10.1186/s13014-020-1467-x

Abstract

PurposeTo analyze patterns of failure in patients with LA-NSCLC who received definitive chemoradiotherapy (CRT) and to build a nomogram for predicting the failure patterns in this population of patients.Materials and methodsClinicopathological data of patients with LA-NSCLC who received definitive chemoradiotherapy and follow-up between 2013 and 2016 in our hospital were collected. The endpoint was the first failure after definitive chemoradiotherapy. With using elastic net regression and 5-fold nested cross-validation, the optimal model with better generalization ability was selected. Based on the selected model and corresponding features, a nomogram prediction model was built. This model was also validated by ROC curves, calibration curve and decision curve analysis (DCA).ResultsWith a median follow-up of 28 months, 100 patients experienced failure. There were 46 and 54 patients who experience local failure and distant failure, respectively. Predictive model including 9 factors (smoking, pathology, location, EGFR mutation, age, tumor diameter, clinical N stage, consolidation chemotherapy and radiation dose) was finally built with the best performance. The average area under the ROC curve (AUC) with 5-fold nested cross-validation was 0.719, which was better than any factors alone. The calibration curve revealed a satisfactory consistency between the predicted distant failure rates and the actual observations. DCA showed most of the threshold probabilities in this model were with good net benefits.ConclusionClinicopathological factors could collaboratively predict failure patterns in patients with LA-NSCLC who are receiving definitive chemoradiotherapy. A nomogram was built and validated based on these factors, showing a potential predictive value in clinical practice.

Highlights

According to the latest NCCN guidelines, definitive chemoradiotherapy is the main recommended treatment for unresectable LA-NSCLC [1]
Concurrent chemoradiotherapy (CCRT) improved the survival of patients with LA-NSCLC compared with sequential chemoradiotherapy (SCRT), indicating that local control is important for patient outcome [5]
The inclusion criteria were as follows: (1) patients initially diagnosed with locally advanced lung cancer; (2) patients with pathologically confirmed non-small cell lung cancer; (3) patients who received Intensity modulated radiation therapy (IMRT) to unresectable LA-NSCLC; (4) patients with a total radiation dose ≥50 Gy and who had completed the radiotherapy plan; (5) patients with data on the determination of Epidermal growth factor receptor (EGFR) mutation status; (6) patients who received regular follow-up imaging examinations in our hospital

Summary

Introduction

According to the latest NCCN guidelines, definitive chemoradiotherapy is the main recommended treatment for unresectable LA-NSCLC [1]. Due to the excellent result of the PACIFIC trial [2], an immune checkpoint inhibitor (ICI) was recommended for subsequent maintenance therapy. Patients with this disease staging were heterogeneous, and the 5-year survival rates ranged from 6 to 30% [3]. A previous study showed that radiation technology (intensity modulated radiation therapy (IMRT) vs three-dimensional conformal radiotherapy (3D-CRT)) may be the predictive factor of recurrence patterns [4]. Most patients receiving definitive radiotherapy in our institution were treated by IMRT, and the failure patterns of these patients were different from those previously described. No satisfactory predictive model has been built to assess the failure patterns for LA-NSCLC

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