Transforming growth factor β is a member of a superfamily of polypeptides with diverse and complex biological functions. The report by Sheen-Chen et al suggests an association between serum expression of TGF-β and breast cancer stage and grade of disease. However, as noted by the authors, analyses of the relationship between TGF-β and breast cancer have previously resulted in a number of conflicting reports.1- 4 In fact, this study demonstrated no difference in TGF-β expression in patients with benign breast disease compared with patients with breast cancer. Some reports have demonstrated results completely contrary to the present report, finding decreased TGF-β serum expression, while others have reported results similar to that of Sheen-Chen et al, that decreased TGF-β receptor expression is associated with more advanced breast cancer. These latter studies seem more consistent with the well-recognized growth inhibitory effect of TGF-β on normal mammary epithelial cells. Such data are certainly consistent with a more general phenomenon of malignant disease; that is, regulation of tumor progression is multifactorial. While this report provides a reasonable addition to the already controversial literature on the subject of TGF-β and breast cancer, it aptly demonstrates the broader conclusion that determining reproducible relationships between tumor cell products and clinical prognosis is often difficult.
Staren ED. Serum Levels of Transforming Growth Factor β1 in Patients With Breast Cancer—Invited Critique. Arch Surg. 2001;136(8):940. doi:10.1001/archsurg.136.8.940