Liver function testing is not helpful for early diagnosis of metastatic uveal melanoma.

OBJECTIVE

To study the relevance of liver function test (LFT) results for early detection of liver metastasis of uveal melanoma.

DESIGN

Evaluation of diagnostic test.

PARTICIPANTS

Eighty-eight patients were included in whom metastasis developed while undergoing semiannual follow-up with LFTs, including aspartate-aminotransferase (AST), alanine aminotransferase (ALT), gamma glutamyltransferase (γGT), lactate dehydrogenase (LDH), and phosphatase alkaline (PA). As controls, 174 patients with uveal melanoma without metastasis were included.

METHODS

The diagnostic attributes of sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for each test were estimated from cross-tabulation tables of test results according to the diagnosis of metastasis. The proportions of false-positive results between groups of patients with and without metastasis were compared in log-binomial regression models.

MAIN OUTCOME MEASURES

Sensitivity, specificity, PPV, NPV, and cost evaluation.

RESULTS

Metastases were detected after LFT abnormality (at least 1 abnormal test result) in 40 (45%) patients. The overall sensitivity of LFTs ranged from 12.5% to 58.0%, and the PPV ranged from 9.4% to 38.6%. The overall specificity and NPV were 90% or greater. The proportions of false-positive results between groups of patients with and without metastasis did not differ significantly (all P≥0.38). Using a cost evaluation, semi-annual screening by LFTs was calculated to cost $35.5/year per patient, including liver imaging induced by true and false-positive results.

CONCLUSIONS

Isolated or combined LFTs for AST, ALT, γGT, LDH, and PA are not helpful for detection of early metastasis. However, the high NPVs suggest that LFT screening can allow clinicians to reassure the patient when the LFT results are negative.