How would you mange true anal margin squamous cell carcinoma (with no involvement of anal canal) if wide local excision cannot be done and chemoradiation therapy is being used instead?

There are many facets to this question. First, it is critical to know that this is a surgical disease, and radiation therapy should only be used as a last resort. If there is no involvement of the anal canal, that strengthens the argument for the use of surgery. The situation is rare when radiation therapy should be used and I would first be looking for another surgical opinion or to convey to the surgeon the strong preference for an operation. It is important to define the reason that surgery is not being recommended. Second, the extent of nodal coverage is dependent on the extent of the primary disease. Keeping in mind that this is a skin cancer, for tumors that are not large or deeply invasive I would likely not treat the nodes at all, b...

I agree with Joel. Sometimes clinicians are tempted to treat the mesorectal nodes and internal iliac nodes because that is what we do for tumors involving the anal canal. However as Joel points out, the drainage goes through the inguinals to the external iliacs in most cases. If there is an unusual presentation with a lot of inguinal adenopathy the lymph drainage may change, and you may see retrograde flow. If the tumor is extending into the anal canal that would probably be a reason to treat the mesorectal nodes.

The other question the comes up a lot is "when do you treat postoperatively after a completely excised anal margin cancer?" This is a little controversial, but I would consider treatment for patients with T2 and above, realizing t...