How would you manage a localized melanoma of the anal canal with sphincter involvement, but without nodal or distant disease?

Anorectal melanoma is a rare entity and I have very limited experience. I summarized my experience in a different question on this forum "How would you approach a patient with clinical T3N1 anorectal malignant melanoma referred by a surgeon for neoadjuvant therapy?"

For this patient in question, who...