In human breast cancer, poor prognosis has been associated with loss of the cancer cell's response to signaling triggered by the molecule TGF-beta.

To understand this association more clearly, Harold Moses and colleagues at Vanderbilt University, Nashville, used mouse breast cancer cell lines to generate gene expression signatures of breast cancer cells not responsive to TGF-beta and those cells responsive to the molecule. These gene expression signatures were then compared with four existing human breast cancer data sets containing gene expression profiles and associated clinical outcome data for 1,319 patients.

The gene signature representative of no response to TFG-beta correlated with reduced, relapse-free survival in all patients. This association was particularly strong in patients with estrogen receptor–positive cancer, specifically those with the luminal A subtype of breast cancer.

The authors, writing in the Journal of Clinical Investigation, therefore suggest that assessing TGF-beta responsiveness might provide an accurate prognosis to patients with estrogen receptor–positive breast cancer and indicate those patients that would benefit most from aggressive therapy.

SOURCE:
Journal of Clinical Investigation, online edition, May 18, 2009