(ChemotherapyAdvisor)– Gene expression profiling (GEP) and chromosomal analysis show prognosticvalue in patients with uveal melanoma, according to research groups from severalinstitutions within the continental United States and Canada. This conclusionis based on a paper titled “Collaborative Ocular Oncology Group Report Number1: Prospective Validation of a Multi-Gene Prognostic Assay in Uveal Melanoma,”which will bepublished in an upcoming issue of Ophthamology,but is now available online.

In this prospective, multicenter study,the investigators evaluated a 15 gene expression profiling (GEP) assay thatclassifies primary posterior uveal melanomas according to their risk ofmetastasis: class 1 (low metastatic risk) and class 2 (high metastatic risk). Tumorsfrom a total of 459 patients were classified by GEP; the first 260 samples werealso analyzed for chromosome 3 status using a single nucleotide polymorphism assay.As a primary outcome measure, primary tumors were managed and patients were monitoredfor metastasis.

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Four hundred forty-six (446) caseswere successfully classified by GEP: 276 cases (61.9%) were class 1 and 170cases (38.1%) were class 2. Median follow-up was 17.4 months (mean, 18.0 months).Metastasis was detected in 3 class 1 cases (1.1%) and 44 class 2 cases (25.9%)(log-rank test, P<10−14). Although there was anassociation between GEP class 2 and monosomy 3 (Fisher exact test, P<0.0001),54 of 260 tumors (20.8%) were discordant for GEP and chromosome 3 status, amongwhich GEP demonstrated superior prognostic accuracy (log-rank test, P=0.0001).

The investigators concluded that theGEP assay was the most accurate prognostic marker among all of the factorsanalyzed and chromosome 3 status did not provide prognostic information thatwas independent of GEP.