Background: Transforming growth factor-beta1 (TGF- beta1) is a multifunctional factor and is known to affect tumor growth in malignant tumors. The effects of TGF-beta1 on angiogenesis, stromal formation, and immune function suggest its possible involvement in tumor progression. The authors examined whether TGF-beta1 levels may be correlated with angiogenesis, clinicopathologic factors, and survival in patients with surgically resected lung carcinoma.
Methods: TGF-beta1 protein was extracted from 53 nonsmall cell lung carcinoma tissue samples (19 squamous cell carcinomas, 33 adenocarcinomas, and 1 adenosquamous cell carcinoma), and its level was measured by enzyme-linked immunosorbent assay. To assess tumor angiogenesis, microvessel density (MVD) was determined by CD31 immunostaining.
Results: The protein level of TGF-beta1 was 289 picograms per milligram of protein (pg/mg protein), ranging from 94 pg/mg protein to 584 pg/mg protein. The TGF-beta1 protein level was significantly higher in patients with lymph node metastasis compared with patients who were without lymph node metastasis (P = 0.02), and the TGF-beta1 protein level was significantly higher in patients with Stage III disease (TNM classification) compared with patients who had Stage I and II disease (P = 0.03). There was no significant correlation between the TGF-beta1 protein level and any of the other clinicopathologic factors that were considered. A significant positive correlation between TGF-beta1 protein level and MVD was noted (P < 0.01). Furthermore, in patients with adenocarcinoma, a significant correlation between TGF-beta1 protein level and prognosis was detected by multivariate analysis (P = 0.028).
Conclusions: TGF-beta1 seems to affect tumor angiogenesis and to play an important role in tumor progression in patients with nonsmall cell lung carcinoma. Furthermore, the TGF-beta1 protein level may be an independent predictor of survival in patients with adenocarcinoma of the lung.
Copyright 2001 American Cancer Society.