Radiation Approaches for CSCC and Standard of Care

Glenn J. Hanna, MD: Thinking about leading the patient in the clinic, let’s turn to Dr Bakst and ask the question. Radiation is important for most cutaneous skin. There’s the question of adjunct radiation and what features would drive you to consider that a patient would have surgery before or after they would need it, or the definitive radiation in lieu of surgery sometimes with some sensitization using a systemic therapy. Walk us through what you’re thinking about when deciding or a recommendation about radiation for cutaneous squamous cell carcinoma.

Richard Bakst, MD: In the definitive setting, we have to think about who’s resectable and who’s not. If you have disease with perineural tumor spread, and you’re not going to obtain negative margins, you have to chase the nerve back to the base of skull. I’m not sure what surgery could achieve in those cases. Obviously, it’s important to discuss that with your head-and-neck surgeon, but those procedures could be quite morbid. As Dr [Kevin] Emerick said, you’re going to have to sacrifice the facial nerve to clear the margins. That’s when we begin to think about shifting to a radiation-based approach, with or without systemic therapy. Obviously, we also see these very nasty large ulcerative lesions that are bleeding in someone who’s older and not medically fit for surgery. Those are also very good cases for definitive radiation.

In the adjuvant setting, we see 2 flavors. One is from the dermatologic surgeons, who may do Mohs. They realize they have to keep going deeper to clear. Ultimately, they never clear the margin, and they’re concerned, so they send them to us. Truthfully, those cases are a little harder to interpret because we’re getting an idea of what the actual path showed to be difficult. And there, the art lies in the conversation: what did they see and what were they concerned about? Things like that. In a true oncological resection, we think about traditional risk factors, perineural invasion, lymphovascular invasion, the number of nodes, the depth of invasion. All those factored into high-risk profiles, and we make it adjuvant.

This transcript has been edited for clarity.