Improved survival with dose escalated radiotherapy in Stage III non-small cell lung cancer : Analysis of the National Cancer Data Base
A partir des données du registre américain des cancers portant sur 33 566 patients atteints d'un cancer du poumon non à petites cellules de stade III traité par chimioradiothérapie entre 2004 et 2012, cette étude met en évidence une amélioration de la survie globale chez les patients ayant reçu une radiothérapie avec escalade de doses
Background : Concurrent chemoradiation is the standard of care in non-operable stage III non-small cell lung cancer (NSCLC). Data has suggested a benefit of dose-escalation, however results from the randomized dose-escalation trial RTOG 0617 revealed a lower survival rate with high-dose radiation. To evaluate the impact of dose-escalation on overall survival (OS) in stage III NSCLC treated with chemoradiotherapy outside the controlled setting of a randomized trial, we performed an observational, population-based investigation of the National Cancer Data Base (NCDB). Patients and Methods : A total of 33,566 patients with stage III NSCLC treated with chemoradiation from 2004 – 2012 and radiation doses between 59.4 -85 Gy were included. The primary end-point was OS, median survival calculated via Kaplan-Meier. Univariate, multivariable and propensity-score matching analyses were performed. Results : Patients were stratified by dose with median OS of: 18.8, 19.8 and 21.6 months for cohorts receiving 59.4-60 Gy, 61-69 Gy, and≥70 Gy respectively (p<0.001). Granular dose analyses were performed demonstrating increased OS with increasing radiation dose: median survival of 18.8, 21.1, 22.0 and 21.0 months for 59.4-60, 66, 70 and≥71 Gy respectively. While 66, 70 and≥71 Gy resulted in increased OS in comparison to 59.4-60 Gy, no significant difference in OS was observed when comparing 66 to≥71 Gy (p=0.38). Conclusions : Dose escalation above 60 Gy was associated with improved OS in this cohort of stage III NSCLC patients treated with chemoradiotherapy. A plateau of benefit was observed, with no additional improvement in OS with increased dose (≥ 71 Gy) compared to 66-70 Gy. With evidence suggesting worse OS and quality of life with increased dose, these data support investigation of the role of intermediate-dose radiation, and in the absence of randomized evidence, may be leveraged to justify utilization of intermediate-dose radiation.