Choroidal-ciliary body melanoma. A multivariate survival analysis of tumor location.

BACKGROUND

Posterior uveal melanomas with ciliary body involvement have greater mortality when compared with choroidal melanomas. This study was conducted to determine if this association is due to an independent effect or to correlations with other parameters.

METHODS

From the 4335 cases of uveal melanoma with follow-up data in the Registry of Ophthalmic Pathology, 664 were selected; therefore, approximately two thirds of the patients died of metastatic melanoma. Ciliary body involvement was determined by the location of the anterior tumor margin. Kaplan-Meier survival, Cox regression, and Gamel-Boag log-normal regression analyses were performed. Covariables included ciliary body involvement, largest tumor dimension, mean diameter of the largest ten nucleoli, and modified Callender classification.

RESULTS

Kaplan-Meier and univariate Cox analyses indicated a significant association between ciliary body involvement and tumor-related death but when included in a multivariate Cox model, ciliary body involvement was not statistically significant. Similarly, when ciliary body involvement was included in a multivariate Gamel-Boag model, ciliary body involvement was not statistically significant. Melanomas that involve the ciliary body were more likely to be larger (Student's t = 10.5; P = 10(-6)), contain larger nucleoli (Student's t = 2.43; P = 0.015), and be of mixed cell type (chi-square = 17.2; P = 3 x 10(-5)).

CONCLUSIONS

Ciliary body involvement is associated with tumor-related mortality but this association is primarily due to ciliary body tumors being larger with more malignant cytology.