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10 slides generated from the cancer page, with a quiz from the open benchmark and speaker notes that cite the sources. Arrow keys move between slides; Print gives one slide per page.
Mucosal melanoma grows on the moist linings of the nose, mouth, anus or genital tract rather than on sun-exposed skin, so it is found late and carries fewer of the mutations that make skin melanoma visible to the immune system. Immunotherapy helps less often than in skin melanoma; a minority of tumours has a KIT mutation that the pill imatinib can target.
Mucosal melanoma arises from melanocytes in the sinonasal tract, oral cavity, anorectum, vulva, vagina and, rarely, the urinary tract, biliary tree and oesophagus. It is not caused by ultraviolet light and its genome differs from cutaneous melanoma: a low mutation burden, frequent structural rearrangements and amplifications, KIT mutations or amplifications in a substantial minority, SF3B1 mutations, and BRAF V600 mutations in only about one in twenty. Presentation is late because the sites are hidden, and most patients have thick, often ulcerated or multifocal primaries; five-year survival is well below that of cutaneous melanoma at any stage.
Surgery is the mainstay for localised disease, but local recurrence is frequent and radical operations at head and neck or anorectal sites carry heavy morbidity, so postoperative radiotherapy is often added to improve local control even though it has not lengthened survival. In China, where the disease is common, a randomised trial found adjuvant temozolomide-cisplatin chemotherapy improved relapse-free and overall survival over high-dose interferon and observation, and it remains an option there. Sentinel node biopsy is less standardised than in cutaneous disease.
| Setting | Approach | Guideline |
|---|---|---|
| Localised disease | Wide surgical excision with the least morbid operation that clears margins; postoperative radiotherapy for head and neck and anorectal primaries to improve local control. | not mapped |
| Adjuvant | Anti-PD-1 antibody as for cutaneous stage III disease by extrapolation; temozolomide-cisplatin chemotherapy is an option in China on a randomised trial. | not mapped |
| Advanced, first line | Nivolumab plus ipilimumab (higher response than nivolumab alone in the pooled analysis) or anti-PD-1 monotherapy; toripalimab with axitinib in China. | not mapped |
| KIT-mutant disease | Imatinib for exon 11 or 13 mutations after or alongside immunotherapy; nilotinib is an alternative. | not mapped |
| NRAS-mutant disease | Tunlametinib (approved in China) or MEK inhibitor trials; naporafenib with trametinib in the SEACRAFT-2 trial. | not mapped |