Staging of Ciliary Body and Choroidal Melanomas Based on Anatomic Extent

<jats:sec><jats:title>Purpose</jats:title><jats:p> To refine the anatomic classification and staging of ciliary body and choroidal melanomas in the TNM classification. </jats:p></jats:sec><jats:sec><jats:title>Patients and Methods</jats:title><jats:p> Tumor largest basal diameter and thickness of 7,369 patients were analyzed based on registry data from five ocular oncology centers. T categories were derived empirically by dividing data into blocks representing 3- × 3-mm fractions. Blocks with similar survival were grouped together so that no T category comprised a large majority of tumors, and each was uniform in survival, using randomly drawn 60% building and 40% validation data sets. Presence of ciliary body involvement (CBI) and extraocular extension (EXE) was analyzed among 5,403 patients to define T subcategories. Stages were generated by iteratively combining subcategories with similar survival. </jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p> Of the 7,369 tumors analyzed, 24% were classified as T1, 33% as T2, 31% as T3, and 12% as T4. Ten-year Kaplan-Meier survival estimates for the T categories were 89%, 77%, 58%, and 39%, respectively (P &lt; .001). Survival of patients in four subcategories based on presence or absence of CBI and EXE differed significantly within each T category (P = .018 for T1; P &lt; .001 for T2 to T4). EXE exceeding 5 mm in largest diameter carried a worse prognosis than smaller extensions (P &lt; .001) and was assigned a separate subcategory. Ten-year Kaplan-Meier survival estimates for stages I, IIA to IIB, and IIIA to IIIC were 88%, 80%, 67%, 45%, 27%, 10%, respectively (P &lt; .001). </jats:p></jats:sec><jats:sec><jats:title>Conclusion</jats:title><jats:p> This evidence-based anatomic classification provides a basis for staging ciliary body and choroidal melanomas in the seventh edition of the Cancer Staging Manual of the American Joint Committee on Cancer. </jats:p></jats:sec>