WASHINGTON — Older age and disease location appear to contribute to the generally poor prognosis of patients who have mucosal melanoma, according to two retrospective studies reported at the Sixth International Conference on Head and Neck Cancer.
Reports in the medical literature note that mucosal melanoma, which occurs most often in the head and neck, constitutes 0.8%–3.7% of all melanomas. It is diagnosed so infrequently that identifying prognostic variables has been difficult, said Thomas Loh, M.D., of the department of otolaryngology and surgical oncology at the National University of Singapore.
When Dr. Loh was a fellow at the University of Toronto's Princess Margaret Hospital, he and his colleagues conducted a retrospective cohort study of 61 patients who had presented to the hospital with mucosal melanoma during a 41-year period. The cancers included melanomas of the oral cavity, oropharynx, hypopharynx, larynx, and nasal cavity. Most of the melanomas were in the sinonasal (80%) or oral (16%) cavities.
Single-modality treatment with surgery or radiation accounted for therapy for 61% of patients, whereas 38% received treatment with multiple modalities. Local (61%) and distant (50%) residual disease accounted for most tumor recurrences, and 21% of recurrences occurred regionally.
Overall, 28% of the patients had not died specifically of melanoma 5 years after diagnosis. Only a “dismal” 26% were free of disease 2 years after diagnosis, and 8% were free after 5 years, Dr. Loh said at the conference, which was sponsored by the American Head and Neck Society.
However, patients younger than 50 years when diagnosed had a 5-year survival rate of 63%, while those older than 50 years had a 21% 5-year survival rate. Patients, on average, were 65 years old.
In the largest study of its kind to date, Eileen H. Dauer, M.D., and her colleagues in the department of otolaryngology at the Mayo Clinic, Rochester, Minn., reviewed all 78 cases of sinonasal melanoma that presented to the clinic during 1963–2003.
Sinonasal melanomas accounted for fewer than 1% of all malignant melanomas and 4% of sinonasal tumors overall. Estimated survival rates ranged from 13% to 45%, according to small retrospective studies.
Patients most commonly presented with symptoms of nasal obstruction and epistaxis. Tumors were located in a variety of subsites, typically the lateral nasal wall and turbinates (57%) and the septum (25%).
Treatments included wide local excision alone in 48% of patients, a combination of wide local excision and radiation in 28%, radiation alone in 16%, and chemotherapy in 8%. Of the 78 patients at Mayo, 17 were not included in the survival analysis because they were treated elsewhere or were only biopsied or debulked.
“It is our practice still to mainly rely on surgery, with radiation therapy as a useful adjunct,” Dr. Dauer said.
Tumors recurred locally in 36 patients after an average of 21 months (median of 9 months). The recurrence rate was 36% after 1 year and 61% after 3 years. Regional metastases developed in 19 patients after an average of 22 months (median of 16 months). A total of 38 patients had distant metastases, which occurred after an average of 28 months (median of 12 months, with a range of 1 month to 212 months). After 1 year, 30% of patients had distant metastases, 53% had them after 3 years.
“Quite sobering,” Dr Dauer said concerning the expected survival of a patient with distant metastases: The median time to death was 3 months. In this study, 53% of patients were alive at 3 months, 32% at 6 months, and 15% at 12 months. One year after treatment, 74% of patients had not died specifically of melanoma, but this dropped to 52% at 3 years and to 23% at 5 years. On average, patients died after 35 months (median of 20 months, ranging from 3 months to 223 months).
After a mean follow-up of 43 months (median of 21 months) among the 61 patients, 46 died from the disease and 11 died from other or unknown causes. Four patients are still alive.
Patients with septal involvement had a significantly greater rate of overall survival than did those without it.
Location and volume of the tumor were the only significant prognostic factors for sinonasal melanoma in a multivariate analysis.