Predictive value of the seventh edition American Joint Committee on Cancer staging system for conjunctival melanoma

Abstract

Objective: To evaluate the predictive value of the seventh edition American Joint Committee on Cancer (AJCC) staging system for conjunctival melanoma.

Methods: Retrospective, observational case series of 42 eyes of 42 patients with conjunctival melanoma studied by reviewing medical records, pathology reports, and color photographs. The main evaluated outcomes were demographic information, laterality, tumor size, thickness, pathologic diagnosis, seventh edition AJCC stage (clinical and pathologic), recurrence, metastasis, and duration of follow-up.

Results: There was no sex preference, and the median age was 61 years. Recurrent disease was noted in 33% of patients (n = 14 of 42), with 64% occurring at a median of 2.5 years (range, 1-5 years) after primary treatment. Metastasis was noted in 19% of patients. The significant predictive factors for high risk of tumor recurrence were tumors involving more than 1 quadrant (P = .02), tumors thicker than 0.5 mm (P = .04), and tumor multifocality (P = .04). The significant predictive factors for high risk of tumor metastasis were tumors thicker than 0.5 mm (P = .005), tumor invasiveness (P = .04), pathologic diagnosis of conjunctival melanoma rather than melanoma in situ (P = .04), and tumor recurrence (P < .001). Similarly, increasing AJCC T stages (clinical and pathologic) were associated with unfavorable outcomes. For example, clinical stage-related recurrence rates were 19% (Tis), 27% (T1), 33% (T2), and 75% (T3). Clinical stage-related lymphatic and distant metastasis rates were 0% (Tis), 20% (T1), 0% (T2), and 63% (T3).

Conclusions: Advanced AJCC T-stage (clinical and pathologic) tumors were at higher risk for recurrence and metastasis. In this study, the seventh edition AJCC staging system was predictive of local control and systemic spread of conjunctival melanoma.