APR 11, 2019
This retrospective study describes the clinical features noted in patients younger than 21 who have posterior uveal melanoma.
Researchers identified patients younger than 21 years who were diagnosed with posterior uveal melanoma at a single center between 1980 and 2013, and examined their medical records through 2017.
Of the 2,265 patients with posterior uveal melanoma identified during the study period, only 18 (0.8%) were younger than 21 years at presentation. The average age at time of treatment was 16.6 years (range 4.4 to 20.8 years). The majority of patients were older than 15 years (n=14) and female (n=10). All 8 patients who developed metastatic disease died of metastasis. Approximately 30% of patients in the full group died of metastasis at 5 years, 48% at 10 years and 58% at 15 years.
On average, the largest basal diameter of the tumor was 12.8 mm and the maximal tumor thickness was 7.2 mm. According to the TNM classification system (7th edition), there were 3 T1 cases, 7 T2 cases, 6 T3 cases and 2 T4 cases. None of the patients had a family history of uveal melanoma or BAP1 tumor predisposition syndrome. One patient exhibited oculodermal melanocytosis; the patient presented with extraocular extension at age 4 and had the most advanced tumor assessed.
It would have been interesting to see the family history and to include citations of germline BAP1 mutation frequency in this cohort. BAP1-associated cancers (e.g., uveal melanoma, mesothelioma, cutaneous melanoma, renal cell carcinoma) can present over time; the lack of family history of BAP1 cancers observed in this study may be due to patients having relatively young family members. Due to the higher rate of germline BAP1 pathogenic alterations (mutations and deletions) in this group, which comprised approximately 7% of uveal melanoma patients under age 30 years, testing for a BAP1 germline mutation that includes assessment for whole gene deletion is recommended.
Although posterior uveal melanoma developed in less than 1% of young patients (<21 years), metastatic disease developed in a significant proportion of these patients and their prognosis was similar to or worse than in adults. A lower threshold to diagnose uveal melanoma in young patients may be useful because early, aggressive treatment may reduce the risk of metastatic disease. Since metastatic disease may develop after 10 years of follow-up, education and systemic monitoring in this high-risk group are very important.