Purpose:
Determine the relationships between gene expression profile (GEP), cytology, and size of melanocytic uveal tumors sampled by FNAB, and comment on patient survival.
Methods:
Prospective study of 205 patients with a posterior uveal melanoma that underwent prognostic FNAB of their tumor. In each case, at least 2 aspirates were obtained and submitted for cytopathology and GEP classification. The relationships between GEP class, cytologic classification, tumor size, and intraocular tumor location were studied by cross tabluation analysis. Survival was computed using the Kaplan-Meier method. The significance of differences between subugroups was evaluated by the logrank test.
Results:
75% of patients 55 years of age or younger had a GEP class 1 tumor. This proportion decreased with older age. Patients with smaller tumors (LBD ≤ 10mm) had a higher percentage of class 1 tumors (79.2%) than those with larger tumors (LBD > 15 mm) (48.6%). 75% of purely choroidal tumors were GEP class 1 while more than 50% of tumors involving ciliary body were GEP class 2. The table below reveals the cytologic diagnosis versus GEP classification. 43 of the 204 tumors (21.1%) yielded an insufficient specimen for cytodiagnosis while only 1 tumor specimen was insufficient or GEP (0.5%). Currently, 189 patients are alive without metastasis (92.2%). 12 patients have died of confirmed/probable metastatis, 3 of them had a GEP class 1 tumor and 9 had a GEP class 2 tumor. 3-year cumulative actuarial survival based on deaths from metastasis in the group was 79.7%. 3-year cumulative actuarial survival was 95.7% in the GEP Class 1 subgroup versus 59.6% in the GEP Class 2 subgroup (p = 0.007, logrank test).
Conclusions:
GEP was more robust discriminator between surviving patients and those dying of metastasis than any other evaluated variable, and much more likely than cytology to assess prognosis based on the yielded tumor cells.
Keywords: melanoma • gene/expression • pathology: human