New edition of classification system for uveal melanoma offers improvements

The latest revision of a system for classifying malignant uveal melanoma offers some improvements over the previous version, but there is still room for improvement, according to researchers who compared the two versions.

Emma Kujala, MD and Tero Kivelä, MD, reviewed the charts of 289 patients who had ciliary body and choroidal melanomas treated in Helsinki between 1962 and 1981, and they classified the tumors based on the sixth edition of the tumor, node, metastasis classification (TNM6), which was adopted in 2003, and the previous edition (TNM5). The researchers evaluated tumor dimensions, ciliary body involvement and extraocular extension from histopathologic sections, and tumors were assigned into categories and stages based on the two versions.

The study authors found that TNM6 reclassified 36% of those previously identified as small tumors to medium-sized tumors and reclassified 65% of those previously identified as large tumors to the medium category as well. TNM6 also provided a wider separation of the survival curves than the previous version.

Areas where TNM6 can still be improved “include taking into account ciliary body involvement and extraocular extension in more detail and combining into each stage tumor categories with similar rather than different prognosis,” the authors said.

Their evaluation is published in the June issue of Ophthalmology.