Multifactorial risk factors for mortality after chemotherapy and radiotherapy for non-small cell lung cancer

Gilles Defraene*, Frank J W M Dankers, Gareth Price, Ewoud Schuit, Wouter van Elmpt, Soumia Arredouani, Maarten Lambrecht, Joost Nuyttens, Corinne Faivre-Finn, Dirk De Ruysscher

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

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Abstract

BACKGROUND AND PURPOSE: A higher radiation dose to the heart is known to be associated with increased mortality in non-small cell lung cancer (NSCLC) patients. It is however unknown what the contribution of the heart dose is when other risk factors for mortality are also accounted for.

MATERIALS AND METHODS: We constructed and externally validated prediction models of mortality after definitive chemoradiotherapy for NSCLC. Models were developed in 145 stage I-IIIB NSCLC patients. Clinical (performance status, age, gross tumour volume (GTV) combining primary tumour and involved lymph nodes, current smoker) and dosimetric (mean lung (MLD) and heart (MHD) dose) variables were considered. Multivariable logistic regression models predicting 12 and 24 month mortality were built in 5-fold cross-validation. Discrimination and calibration was assessed in 3 external validation datasets containing 878 (via distributed learning), 127 and 96 NSCLC patients.

RESULTS: The best discriminating prediction models combined GTV, smoker and/or MHD: bootstrapping AUC (95% CI) of 0.74 (0.66-0.78) and 0.69 (0.55-0.74) at 12 and 24 months. At external validation, the 24 month mortality GTV-smoker-MHD model robustly showed moderate discrimination (AUC = 0.61-0.64 before and 0.64-0.65 after model update) with limited 0.01-0.07 improvement over a GTV-only model, and calibration slope (0.64-0.65). This model can identify patients for whom a MHD reduction may be useful (e.g. PPV = 77%, NPV = 52% (60% cut-off)).

CONCLUSIONS: Tumour volume is strongly related to mortality risk in the first 2 years after chemoradiotherapy for NSCLC. Modelling indicates that efforts to reduce cardiac dose may be relevant for small tumours and that smoking has an important negative association with survival.

Original languageEnglish
Pages (from-to)117-125
Number of pages9
JournalRadiotherapy and Oncology
Volume152
Early online date20 Sept 2019
DOIs
Publication statusPublished - Nov 2020

Keywords

  • DOSE-ESCALATION
  • Lung cancer
  • Mean heart dose
  • Overall survival
  • PHASE-III
  • PREDICTION MODEL
  • PROGNOSTIC-FACTOR
  • PROTON THERAPY
  • Prediction model
  • Proton therapy
  • RADIATION-THERAPY
  • RTOG 0617
  • SECONDARY ANALYSIS
  • STAGE
  • TUMOR VOLUME
  • HEART

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