The alteration of plasma TGF-β1 levels in patients with brain tumors after tumor removal.

Transforming growth factor (TGF) β1 may be a candidate for a serologic tumor marker. In this study, the plasma levels of TGF-β1 in patients with brain tumors were measured using enzyme-linked immunosorbent assay before and after tumor removal. Patients were divided into four groups, the control group and the benign, malignant, and metastatic brain tumor groups. All brain tumor groups showed significant increases in the levels of TGF-β1 before tumor removal (6.36 ± 3.94, 17.0 ± 9.7, and 12.2 ± 10.3 ng/ml for the benign, malignant, and metastatic groups, respectively). When compared with the results obtained in the control group (1.12 ± 0.74 ng/ml), significant decreases in TGF-β1 concentrations after total tumor removal were found in both the benign and malignant brain tumor groups (2.55 ± 2.00 and 8.93 ± 5.73 ng/ml, respectively; p = 0.0001 and p = 0.003, respectively). On the other hand, plasma TGF-β1 levels in the metastatic brain tumor group showed a slight but significant increase (14.7 ± 9.3 ng/ml, p = 0.035) after tumor removal. In a case of low-grade astrocytoma, plasma levels of TGF-β1 were found to be 3.6 and 1.1 ng/ml before and after tumor removal, respectively. However, recurrent tumor was noted in this patient 7 months later, and the levels of TGF-β1 were 26.2 and 8.4 ng/ml before and after the second operation, respectively. The data show that plasma TGF-β1 was elevated in the circulation of patients with brain tumors and that significant decreases in TGF-β1 levels were observed after the removal of benign and malignant tumors. The results also suggest that TGF-β1 may be a useful serologic marker for brain tumors.