This transcript has been edited for clarity.
I’m Mark Kris from Memorial Sloan Kettering, speaking today about a topic that’s become quite controversial, which is
Data from clinical trials and data from a SEER study showed approximately 7% improvement in overall survival in patients with N2 disease who received PORT. There has been a very clear demonstration of an improved local control rate in every trial that’s ever looked at PORT.
However, there was a randomized trial, the Lung ART trial, where patients were randomized to get PORT or not. PORT was delivered in a way that is not routinely used now. In that trial, the benefit of PORT was found in terms of local control, almost doubling control within the mediastinum.
The difference in overall survival was less than 12%. Again, I’m not surprised to see that because the improvement in overall survival is probably somewhere between 5% and 10%. They also found an excess of deaths, probably due to cardiac causes from the radiation in the radiation arm.
However, the trial used a type of radiation not used at this point – it used conformal, but now we would use 3D. And its ability at the time of the trial to estimate and lower cardiac risk was not what it is today. Owing to the design of the trial, it was not a significant difference and has largely been interpreted as saying that the PORT doesn’t work.
First, let’s please go to the guidelines. I’m going to the ASCO guidelines, which say that patients with mediastinal disease should not routinely get PORT, but they should be routinely referred to a radiation oncologist for consideration of PORT. I don’t think anything that’s been published so far changes that.
I think each case needs to be individualized and requires the specialty care of a radiation oncologist to weigh the pros and cons of PORT. It also depends upon the treatment plan. Can the heart be spared? Are there radiation techniques available that would eliminate or lessen heart exposure, such as using protons? The point is that PORT is still needed.
When we look at the trials of patients receiving adjuvant therapy – and I’m looking particularly at the ADAURA trial where patients received adjuvant osimertinib – the greatest number of failures now is in the chest. We have to look for good ways to cut down on failure in the chest. Unfortunately, failure in the chest means ultimately failure and lack of cure, and we have to do a better job at that. I think PORT can play a role there.
Please, when you have patients with N2 disease, after the completion of systemic therapies, think about the use of PORT and get the advice of a radiation oncologist to meet with the patient, review their clinical situation, and assess whether or not PORT could be useful for that patient.
That is following the NCCN guidelines, which were not changed on the basis of the Lung ART paper. I think we owe it to our patients to make sure that those who could benefit from this additional therapy receive it.
I’ll put it to you that radiation delivered in the most innovative way – taking very careful account of the effects on the heart – can improve local control. There’s no question about that. I think PORT has the ability to improve survival by a small amount – probably less than 12%, which I will agree the Lung ART trial showed – but still an important amount for patients with this condition.
Mark G. Kris, MD, is chief of the thoracic oncology service and the William and Joy Ruane Chair in Thoracic Oncology at Memorial Sloan Kettering Cancer Center in New York City. He reported conflicts of interest with Arial Pharmaceuticals, Pfizer, PUMA, and Roche/Genentech. A version of this article first appeared on Medscape.com.