Age, survival predictors, and metastatic death in patients with choroidal melanoma: tentative evidence of a therapeutic effect on survival.

OBJECTIVE: To determine whether treatment of choroidal melanoma influences survival by correlating age at death, cause of death, age at treatment, and survival predictors.

DESIGN, SETTING, AND PARTICIPANTS: Prospective cohort study performed at the Liverpool Ocular Oncology Centre, a supraregional, tertiary referral service in England. We included 3072 patients treated for choroidal melanoma from January 15, 1993, through November 23, 2012, and who reside in the mainland United Kingdom.

EXPOSURES: A diagnosis of choroidal melanoma (ie, any uveal melanoma involving the choroid).

MAIN OUTCOMES AND MEASURES: Largest basal tumor diameter, tumor thickness, TNM stage, ciliary body involvement, extraocular spread, melanoma cytomorphological findings, closed connective tissue loops, mitotic count, chromosome 3 loss, chromosome 6p gain, chromosome 8q gain, age at treatment, age at death, and cause of death.

RESULTS: The largest basal tumor diameter correlated with all survival predictors except for chromosome 6p gain. Older age at treatment correlated with ciliary body involvement, extraocular spread, largest basal tumor diameter, tumor thickness, TNM stage, epithelioid cells, chromosome 3 loss, and chromosome 8q gain. A total of 1005 patients had died by the close of the study. The cause of death was metastatic disease due to uveal melanoma in 561 patients. Among the 561 patients, survival time after treatment correlated with sex, basal tumor diameter, ciliary body involvement, extraocular spread, TNM stage, closed loops, and mitotic count. In this group of patients, none of the survival predictors correlated with age at death except for mitotic count, which showed a weak correlation. All survival predictors correlated with an increased likelihood of metastatic melanoma as the cause of death.

CONCLUSIONS AND RELEVANCE: Patients who are younger at the time of treatment tend to have a smaller, less extensive tumor with a lower degree of malignancy. A tentative explanation for these findings is that ocular treatment prevents tumor growth, dedifferentiation, and metastatic disease in some patients, especially those with a smaller tumor.