Early diagnosis and monitoring of transplanted human malignant mesothelioma by serum hyaluronic acid.

Serum concentrations of unhydrolyzed hyaluronic acid (HA) in nude mice bearing human malignant mesothelioma xenografts were determined by size-exclusion chromatography. HA rose to 8-16 micrograms/mL (controls: less than 1 micrograms/mL) by the fourth to fifth day after tumor (epithelial) transplantation, 3 to 5 days before palpability. Decreases in HA during late tumor growth are probably attributed to tumor necrosis, based on the observation that HA was 2.5 times less in necrotic than in viable tumor tissues. This serum biomarker, recognizable before physical detectability of xenografted tumors, should have applicability to monitoring experimental chemotherapy in mice and to early diagnosis and monitoring of human malignant mesothelioma.