Factors affecting eye conservation and metastasis in posterior uveal melanomas.

PURPOSE: To determine the effect of patient and tumor features and different treatments on eye removal (enucleation or exenteration) and metastasis in posterior uveal melanoma (PUM).

METHODS: Retrospective analysis. Patient age (≤60 vs >60 years), sex (female vs male), visual acuity (VA, ≤20/40 vs >20/40), largest tumor basal diameter (LTBD), tumor thickness, tumor stage according to American Joint Committee on Cancer (AJCC) 8th edition, ciliary body involvement, distance to optic disc (OD)/fovea (≤3 mm vs >3 mm), OD involvement, and histopathology were evaluated. Primary treatment options were transpupillary thermotherapy, plaque radiotherapy, Cyberknife radiosurgery, exoresection, and eye removal. Risk factors for primary eye removal were determined using logistic regression test and those for secondary eye removal and metastasis with Cox regression analysis.

RESULTS: Of 387 cases, 153 (39.5%) underwent primary eye removal. Multivariable risk factors for primary eye removal included AJCC tumor stage (p = 0.001, OR:4.586; p < 0.001, OR:34.545; p < 0.001, OR:103.468 for stages T2, T3, and T4 vs stage T1, respectively), and VA≤20/40 (p = 0.014, OR:2.597). Multivariable risk factors for secondary eye removal were VA≤20/40 (p = 0.019, RR:2.817) and AJCC stage T3 vs T1 (p = 0.021, RR:2.666). Eye preservation rates in patients undergoing eye-conserving treatments were 80.3%, 69.6%, and 51.5% at 5, 10, and 15 years, respectively. Metastasis-free survival rates were 81.0%, 73.0%, and 56.7% at 5, 10, and 15 years, respectively. Multivariable risk factors for metastasis included eye removal as primary treatment (p = 0.005, RR:2.828) and mixed type histopathology (p < 0.001, RR:4.804).

DISCUSSION: Early diagnosis is crucial for both eye preservation and survival in PUM. Increasing AJCC tumor stage and lower VA were risk factors for eye removal in this study. Mixed type histopathology and primary eye removal were risk factors for metastasis.