medwireNews: Patients with completely resected stage IIIA N2 non-small-cell lung cancer (NSCLC) do not benefit from postoperative radiotherapy (PORT), show the results of the phase 3 Lung ART trial presented at the ESMO Virtual Congress 2020.
In a statement to the press, presenting author Cécile Le Pechoux (Institut Gustave Roussy, Paris, France) said: “PORT cannot be recommended for all patients with stage II and III NSCLC with mediastinal nodal involvement.”
However, she noted that PORT could be useful for some patients “because it does decrease the rate of mediastinal relapse by 50% [but this] must be put into balance with the risk of over-added cardio-pulmonary toxicity.”
The study included 501 patients (median age 61 years, 66% men) who were randomly assigned to receive mediastinal PORT (54 Gy in 27–30 fractions; n=252) or no PORT (n=249) following complete resection.
The most common cancer type was adenocarcinoma and most patients received either preoperative (13%) or postoperative (96%) chemotherapy. The majority were staged before treatment using positron emission tomography.
Le Pechoux reported that, after a median 4.8 years of follow-up, median disease-free survival was 30.5 months among the patients who received PORT and 22.8 months among those who did not, with 3-year disease-free survival (DFS) rates of 47.1% and 43.8%, respectively.
When the researchers looked at the types of DFS events, they found that mediastinal relapse as a first event was less common with than without PORT (25.0 vs 46.1%), whereas death as a first event was more common (14.6 vs 5.3%).
Discussing the findings, Rafal Dziadziuszko, from the Medical University of Gdańsk in Poland, said that the increased rate of death as a first event corresponds to an increased rate of cardiopulmonary toxicity with PORT.
Indeed, among the 487 patients evaluable for toxicity, 10.8% experienced late grade 3–4 cardiopulmonary toxicity in the PORT group compared with 4.9% in the control group.
Furthermore, the overall survival rate at 3 years was 66.5% with PORT and 68.5% without PORT, but the causes of death differed between the groups. More patients in the PORT arm died as a result of cardiopulmonary causes (16.2 vs 2.0%) or treatment-related toxicity (3.0 vs 0.0%) but fewer patients than in the control arm died as a result of progression or recurrence (69.4 vs 86.1%).
Le Pechoux concluded that further research is needed “to determine if certain patients, in particular, could benefit from [PORT].”
Dziadziuszko told the press that not recommending PORT in this setting “will change the practice of many institutions that adopted standard use of radiotherapy in these patients.”
He added: “We can safely say there is no net benefit from such treatment but there is also potential harm, which we see from this study, so any potential benefits in some patients are offset by the predominantly higher risk of cardiopulmonary toxicities.”
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