A discussion on differentiating advanced and metastatic cutaneous squamous cell carcinoma (cSCC).
PUBLISHED June 12, 2020
Anna C. Pavlick, DO: Moving on to our next topic, which is the surgical management of advanced-stage metastatic squamous cell carcinoma of the skin; how would you define the difference between advanced versus metastatic cutaneous squamous cell skin cancer?
Anthony Rossi, MD, FAAD: The high-risk skin cancers, squamous cell carcinoma, are those that are mainly occurring on the head and the neck, especially the mask area of the face. If you had put a mask on a head, you would notice that around the eyes, the mouth, the ears are higher-risk areas that predispose these patients to getting more aggressive lesions in this area. So we really take into account where the squamous cell carcinoma is developing. If the histology is poorly differentiated, if it’s not well differentiated, we know that those can be more aggressive. They can invade; they can spread.
If recurrent tumor has already treated and now has come back, that’s at a higher risk for spreading. In these areas, when we think about these T1 lesions, as we’d call them, those are still amenable to something like Mohs surgery if it’s occurring on the head and in the neck and you use a precise, complete circumferential margin control with histology to really guide the surgery and to make sure that the roots of the skin cancer have been excised.
When those skin cancers have progressed even further and now have developed either in-transit metastasis or regional disease including the lymph nodes, those become an advanced presentation. Now we really need a multidisciplinary approach with our oncologists and our radiation oncologists. We’d like to stratify those lesions as being at higher risk of course, and we need a multidisciplinary approach to treatment.
Anna C. Pavlick, DO: I think it’s so important, especially once these patients get referred to either the head and neck surgeons, that radiation and medical oncology in conjunction with dermatology really discuss this with the patient and what should be done. Because with the onset of these new therapies, like immunotherapy, many of these lesions can be treated without patients having a very disfiguring or aggressive surgery. Now is the big buzzword is neoadjuvant therapy. So using systemic therapy prior to a surgical resection essentially to make the surgery less invasive or less aggressive is really something that really needs to be a multidisciplinary discussion.
Anthony Rossi, MD, FAAD: Yeah, I agree. I think now is an exciting time because we have even more options to treat these patients without having them undergo a very morbid surgery resection or even possible radiation at some point.
Anna C. Pavlick, DO: If you get a patient who has an advanced or a metastatic squamous cell, are there any specific tests you’d like to order to work up their metastatic chances?
Anthony Rossi, MD, FAAD: Surely. We know in the high-risk squamous carcinomas, in-transit region node metastases are the most common. Of course there’s the risk of distant metastasis as well. So there are some variables that are associated with a higher rate of metastasis. If a tumor diameter is greater than 5 centimeters, if it’s poorly differentiated or if the tumor thickness is greater than 6 centimeters and invading into the subcutaneous fat, these all have higher associated risk of local or regional metastases.
The sentinel lymph node is still a bit controversial in squamous cell carcinoma, depending on where you practice or which hospital system you’re in, but I think it’s important to get imaging and an imaging work-up if you’re presented with one of these higher-risk squamous cell carcinomas. Of course your physical exam is important, just to make sure there’s palpable lymphadenopathy in the region, always doing a very thorough physical exam to make sure. Getting baseline imaging can be very helpful, especially if the patient is also complaining of certain neuropathic pain, such as tingling or burning in that area. That could be a tip-off that there is something called perineural invasion or the tumors wrapping around a nerve.