Ablative radiotherapy improves survival in patients with second NSCLC

Ablative radiotherapy for new primaries leads to improved overall survival (OS) compared with initial lung cancer stereotactic body radiation therapy (SBRT) in inoperable patients, a recent study has shown.

Records of inoperable patients who underwent thoracic SBRT from February 2007 to April 2019 were retrospectively reviewed. Those with previous small cell lung cancers or SBRT treatments for tumours other than nonsmall cell lung cancers (NSCLC) were not included.

The authors performed multivariate Cox regression and matched pair cohort analyses to assess the prognoses of patients undergoing definitive SBRT for a new second primary.

Overall, 438 patients with NSCLC were included, of whom 84 had previously received treatment. In univariate log-rank tests, OS was associated with gender, Karnofsky performance status (KPS), prior lung cancer, anticoagulation use, and history of heart disease (p<0.05).

These factors were then integrated into a multivariate Cox regression model. As a result, female sex (hazard ratio [HR], 0.68; p=0.004), KPS (HR, 2.0; p<0.001), and prior lung cancer (HR, 0.7; p=0.049) significantly correlated with OS. A similar approach showed that only gender (HR, 0.64; p=0.017) and tumour stage (HR, 1.7; p=0.02) were associated with relapse-free survival.

Additionally, propensity-score matching was conducted to support the Cox regression analysis using gender, age, KPS, tumour stage, history of heart disease, and anticoagulation use. On Kaplan-Meier analysis within the matched pairs, prior lung cancer was found to correlate with improved OS (p=0.011), but not with relapse-free survival (p=0.44).

“Physicians should not be dissuaded from offering SBRT to such patients,” the authors said.