Cytogenetic analysis may aid in predicting mortality from uveal melanoma

Cytogenetic analysis of certain chromosomal abnormalities, when interpreted with tumor diameter and cell type, can help in predicting patients' disease-specific mortalities after treatment for uveal melanoma, according to a study by researchers in the United Kingdom.

Specifically, "chromosome 3 loss and chromosome 8 gains in uveal melanoma are associated with metastatic death," the study authors said.

Bertil Damato, MD, PhD, and colleagues performed cytogenetic analysis on 356 patients treated for uveal melanoma and correlated their findings with clinical and histologic predictors and disease-specific mortality.

Patients averaged 61.9 years of age. The U.K.'s National Health Service Cancer Registry documented and notified the investigators of any deaths during follow-up, according to the study.

The researchers found no cytogenetic abnormalities in either chromosome 3 or chromosome 8 in 42% of tumors analyzed. Gains in chromosome 8 were seen in 11% of tumors, monosomy 3 was seen in 21% and both abnormalities were seen in 27%, the authors reported.

These results significantly correlated with ciliary body involvement, extraocular spread, large basal tumor diameter, epithelioid cellularity, closed connective tissue loops and a mitotic rate exceeding 4/40 high power fields, according to the study.

Overall, 76 patients died by the end of the study, 67 of whom died due to disease metastasis.

Using Cox multivariate analysis, the investigators found that the most significant factors associated with mortality included basal tumor diameter (P < .001), monosomy 3 (P < .001) and epithelioid cellularity (P = .004).

"Kaplan-Meier analysis showed that 5-year metastatic death rates ranged from 0% in 84 patients with low-grade melanoma to 66% in 100 patients with high-grade tumor," the authors said.

The study is published in the October issue of Ophthalmology.