The big picture.
Top Line: Does adjuvant radiation improve disease-free survival in patients with resected N2 non-small cell lung cancer (NSCLC)?
The Study: You probably already know about the results of the LungART trial. Here we have its final publication, which is a good opportunity to delve into the details and consider the trial’s meaning for the future of post-op radiation therapy (PORT). LungART was a randomized phase 3 European trial of 501 patients with completely resected NSCLC and N2 nodal involvement. Ninety-one percent were staged with PET/CT. They were randomized to receive PORT or no PORT. Almost all patients (96%) received chemotherapy with most receiving adjuvant chemo (75-78%). PORT followed adjuvant chemo. The radiation dose was 54 Gy in either 27 or 30 fractions. The CTV included involved nodal stations with an additional 1 cm CTV margin for microscopic disease, the ipsilateral hilum, the bronchial stump, and stations 4 (lower paratracheal) and 7 (subcarinal). Most patients were treated with 3D conformal (89%) with 11% receiving IMRT. Median mean heart dose was 13.4 Gy (11.7 Gy right-sided tumors, 17 Gy left-sided tumors), and median heart V35 was 15%. Median lung V20 was 23%. At 3-years, PORT did not improve the rate of DFS (47% v 44%). Median DFS 30.5 v 22.8 months. The story is in the breakdown of DFS events, which occurred in 57% with PORT and 61% without. The rate of relapse or metastasis was lower after PORT (49% v 58%), which was driven by a significant reduction in the rate of mediastinal relapse (14% v 28%). However, the reduction in mediastinal relapse did not affect the rates of brain metastasis (13.5% v 11%) or extracranial metastasis (28% v 29%). And while fewer patients died of disease recurrence after PORT (27% v 35%), there was a higher rate of cardiopulmonary death (6% v <1%). As a result, there was no difference in 3-year overall survival (67% v 69%).
TBL: Just like in PORT-C, despite reducing mediastinal relapse, PORT does not significantly improve disease-free or overall survival for patients with resected N2 NSCLC. | Le Pechoux, Lancet Oncol 2021