ORLANDO – Uveal melanoma has little in common with it’s cutaneous namesake, and its distinct characteristics necessitated the development of specific guidelines for diagnosis and management, which were released earlier this year by the National Comprehensive Cancer Network (NCCN).
Unlike cutaneous melanoma, uveal melanoma is usually treated with radiotherapy rather than surgery, and primary treatment is based on tumor size, according to Christopher A. Barker, MD, a radiation oncologist and director of clinical investigations in the department of radiation at Memorial Sloan Kettering Cancer Center, New York.
Further, molecular testing aids in prognosis in uveal melanoma but not in predicting treatment response as it can in cutaneous disease, and recurrences of uveal melanoma are typically distant – usually occurring in the liver – rather than in the skin or lymph nodes as with cutaneous melanoma.
These and other diagnosis- and treatment-related issues are outlined in the new guidelines, which are the first developed by the NCCN for uveal melanoma.
Guidelines exist in several countries, including Australia, the United Kingdom, Canada, and the United States (published by The American Brachytherapy Society), but until now none have provided pathway-based strategies for the management of all stages of this rare disease that affects about 1 in 200,000 Americans, typically Caucasians in their 50s, 60s, or 70s, Dr. Barker, a member of the NCCN Melanoma guidelines panel and the uveal melanoma subcommittee, said at the NCCN’s annual meeting where he presented the guidelines.
The median age of diagnosis is 60 years, he noted.
The NCCN guidelines specifically address melanoma arising in the choroid and ciliary body of the uvea. The choroid is the predominant site of uveal melanoma origin, and tumors arising there may involve the ciliary body as well, although the latter is a rare site of melanoma origin. The iris is also a rare site of origin, and tumors arising there are typically indolent in nature and thus are not part of the new guidelines, he explained.
Risk factors include choroidal nevi, ocular melanocytosis, and familial uveal melanoma associated with germline BAP1 mutation, neurofibromatosis, or dysplastic nevus syndrome; cutaneous melanoma is not a risk factor, he said.
The guidelines address clinical presentation, diagnostic work-up, and staging; primary treatments; and metastatic risks and follow-up imaging.
Presentation, diagnosis, and staging
About two-thirds of patients with uveal melanoma present because of changes in their vision, and about a third present with no new symptoms and are diagnosed during routine evaluation, Dr. Barker said.
“History and physical exam, and specifically attention to any prior malignancies, is important,” he said. “A comprehensive eye examination is absolutely vital to the evaluation and staging of patients with uveal melanoma.”
Numerous additional testing options, including autofluorescence of the ocular fundus, retinal fluorescein angiography of the ocular fundus, and transillumination, among others, are listed in the guidelines, which note that MRI is sometimes needed to confirm diagnosis.
Biopsies, however, are generally only performed to confirm diagnosis if needed or for prognostic analysis for risk stratification.
Staging is determined mainly by tumor size, which is known to be associated with outcomes in patients with uveal melanoma, and is based on criteria from both the Collaborative Ocular Melanoma Study (COMS) staging system and the American Joint Committee on Cancer (AJCC) staging manual, Dr. Barker said.
The COMS system was developed based on separate studies of small, medium, and large tumors and helped define primary tumor management and establish existing standards of care. The AJCC system was developed subsequently and focuses more on tumor features that may improve clinical predictions.