The significance of urinary melanoma antigen excretion and the ability of thymosin to raise the level of depleted lymphocytes in vitro in malignant melanoma.

One hundred and fifty-six patients were screened for the presence of urinary melanoma antigen and serum cytoplasmic antibody. It was found that 44% of symptomless Stage 1 patients tested five to 15 years after operation had detectable antigen (Ag) in their urine; the urines of 67% of Stage 2A (local recurrence) patients were positive for Ag; while in only 38% of those patients graded 2B (lymph-node involvement) were these tests positive. Urines of 83% of patients with generalized metastases (Stage 3) were positive. A sequential study was made of 23 patients seen and treated in 1976. Of this group, 14 reverted from a positive state to a negative one following excision of their tumour, while six were negative on first postoperative testing and subsequently became positive. Three out of the 23 remained persistently negative. T lymphocyte levels were assessed in 71 melanoma patients, and a stage-related fall was noticed. Thymosin (Hoffman LaRoche) on in vitro incubation significantly raised the levels of T lymphocytes.