Commenting on the Lung ART study, Rafal Dziadziuszko, MD, a radiation oncologist from the Medical University of Gdansk, Poland, said: “Congratulations on this study to resolve the longest ongoing debate in thoracic oncology. For more than 20 years, we have been discussing whether to irradiate patients with mediastinal involvement after surgery.”

Dr. Dziadziuszko pointed out that radiation techniques are more modern, and now patients receive adjuvant or neoadjuvant chemotherapy. “Nevertheless, before the results of Lung ART, physicians from around the world hesitated to use postoperative radiotherapy. Arguments in favor of postoperative radiotherapy are increased local control and more modern radiation techniques. Arguments against postoperative radiotherapy include insufficient evidence that survival is prolonged and that the technique has potential harm,” Dr. Dziadziuszko continued. “There is clear evidence of harm of postoperative radiotherapy in patients irrespective of nodal status; patients with no known nodal involvement or hilar nodal involvement should clearly not be irradiated.”

Rafal Dziadziuszko, MD

Long-Awaited Answers

“Most of the studies were done with old-fashioned radiation. Lung ART is a truly large effort to give us some answers,” he said. “Indeed, we can reduce the risk of local relapse using postoperative radiotherapy; however, many of these patients will have distant relapse, and the impact on disease-free survival is moderate at best. Moreover, postoperative radiotherapy comes with increased toxicities that impact the death rate, and it does not increase overall survival,” Dr. Dziadziuszko told listeners.

“The study shows that postoperative radiotherapy indeed is harming some patients, with a higher rate of death at first events. There is no significant disease-free survival benefit with postoperative radiotherapy, and the number of overall survival events is equal in both groups.”

“To understand what happens with postoperative radiotherapy, you avoid 19 deaths due to disease progression or recurrence, but you get an excess of 14 deaths due to cardiopulmonary toxicity, 4 due to secondary cancers, and 3 related to radiotherapy or chemotherapy. This explains why disease-free survival will not translate to survival benefits,” he stated. “The clear message is that routine postoperative radiotherapy should not be used in patients with mediastinal involvement at surgery. We need to look for better therapies.”

“However, an around 46% risk of mediastinal relapse occurs with no postoperative radiotherapy, and this warrants careful follow-up—especially in patients with pN2 disease. These patients should be followed with CT scans and restaging to allow for curative treatment of isolated nodal relapses,” Dr. Dziadziuszko advised. 

DISCLOSURE: Dr. Dziadziuszko has received honoraria from AstraZeneca, Boehringer Ingelheim, Bristol Myers Squibb, MSD Oncology, Novartis, Pfizer, Roche/Genentech, Seattle Genetics, and Takeda and has been reimbursed for travel, accommodations, or other expenses by AstraZeneca and Roche.