The Role of Induction Chemotherapy in HNSCC

Transcript:

Ezra Cohen, MD: Let me revisit an old topic, and that is of induction chemotherapy. Josh, I know you do a fair bit of it, or at least still continue to study it. Tell us, is there a role for induction chemotherapy in locally advanced head and neck cancer? If so, where is it and what’s the field doing?

Joshua M. Bauml, MD: Induction chemotherapy is something that people have studied a lot. The idea is that we can get chemotherapy into a person much faster than the radiation oncologist can set up their simulation. And in addition to that, when we look at concurrent chemoradiation studies in head and neck cancer, what they consistently show is an improved locoregional control with a lack of improvement in distant metastases. We tend to think of chemotherapy spreading throughout the body as a way to diminish those. So, induction chemotherapy is an appealing option. There have been multiple studies looking at this, and it’s difficult to know exactly its place.

The way that I tend to use it in my clinic is for a patient who is unable to tolerate concurrent chemoradiotherapy or who is unable to get radiation quickly. So, one of my colleagues refers to this as the “Christmas rule.” If it’s Christmas Eve, you have a patient, and they have a massive tumor, it might be problematic to get them on to radiation quickly. The reason why I would tend to prioritize chemoradiotherapy over induction is that we don’t have good comparative data to say that induction is better. And we do know that for patients who have induction chemotherapy, there are some of those patients, up to 25% in some studies, who are unable to then receive the concurrent chemoradiotherapy—at least the concurrent chemotherapy component of that. And that’s highly problematic because the concurrent chemoradiotherapy is the definitive part that we think is curing patients. And so, I hesitate to add a treatment that may diminish my ability to administer the curative intent therapy.

Barbara A. Burtness, MD: I would just say that there were large randomized trials—whether or not they had quite the event rate that Ezra and other people who chaired these studies expected—and those studies did not show a benefit for induction. I would actually take a much more conservative view, which is that induction therapy as a way to improve overall survival for unselected patients does not have a role. We continue to use it as therapy for a patient who needs something quickly, and that’s particularly the person who can’t lie flat and have the mask made. So, in situations where you can decrease the size of the tumor and get them to chemoradiation as expeditiously as you can, but make it happen in a way that it couldn’t without the induction therapy—or in someone whose tumor is really so large, the longest dimension, in the 8 cm to 10 cm range, where older data show that CRs are extremely uncommon—we use it there.

The other way that I think about induction, though, is the possibility that it has for predicting how a person is going to do with radiation, so the old University of Michigan chemotherapy selection approach. And you may see a person who’s got an early T4 larynx cancer. Their function was pretty good until recently. You see a little bit of cartilage invasion, but the larynx isn’t gone, and they don’t want a total laryngectomy. I think if you give them a cycle of chemotherapy and you see that there’s no response, you can show them the old data from the University of Michigan. Very clearly, they’re going to be very likely to require a salvage laryngectomy for disease control, not just for functional loss. So, I think in the chemotherapy selection setting, it can be extremely useful.

Transcript Edited for Clarity