Transcript: Anna C. Pavlick, DO: How do you decide between surgery and radiation if a lesion is just too large for a dermatologist to manage?
Anthony Rossi, MD, FAAD: That’s a great question. I think we now have better staging criteria for squamous cell carcinoma. We used to rely solely on the AJCC [American Joint Committee of Cancer] staging criteria, but recently there is the Brigham and Women’s staging criteria, which has really helped delineate which ones are at higher risk for these local recurrences or local and regional metastasis.
This Brigham and Women’s staging has T1, T2a, T2b and T3. The T2b and T3 are the ones that are associated more with these higher events—as you would say, the metastatic spread. T2b and T3 have either 2 or 3 risk factors, or the T3 class has four risk factors or bone invasion. And the risk factors that they determined were tumor greater than 2 centimeters in diameter, poorly differentiated if there is perineural invasion on histology, either on the biopsy or the final excision, or if there’s invasion beyond subcutaneous fat.
Hopefully, the original biopsy would get these criteria if the biopsy encompasses a big part of the lesion. But sometimes we don’t know all these factors until either we’re doing the Mohs surgery at that time or we get the pathology back after a wide local excision if a different modality was used. In that case, when you do have complete histology and you can identify these risk factors, it’s time to determine whether you would proceed with adjuvant radiation or adjuvant immunotherapy if needed.
Anna C. Pavlick, DO: I’m currently running a clinical trial looking to address whether patients with those high-risk factors, because it’s common that they would go on and have adjuvant radiation, will benefit also by getting adjuvant immunotherapy following radiation? I think it’s a very important question because we know that radiation is very effective in controlling localized disease but does very little to prevent systemic diffused disease.
This clinical trial is asking the question, “Can we minimize the chances of local recurrence by giving standard-of-care radiation?” Half of those patients will go on to observation and the other half will go on to receive a year of adjuvant immunotherapy. That’s going to be a very interesting trial, to see if that can then impact the survival of these patients.
Anthony Rossi, MD, FAAD: That’s really exciting. That’s a superimportant question that we need to know because while, as you said, adjuvant radiation is associated with good disease control after an excision that either has very close margins or positive margins, we don’t know how well it’s doing for the distant disease.
Transcript Edited for Clarity