Tamoxifen response in breast cancer predicted by protein marker

the Oncology Nurse Advisor take:

An abnormally low amount of the protein TGFBR2 is associated with resistance to tamoxifen response in breast cancer treatment, according to a study published in Cancer Research.

“Our data indicate that TGFBR2, which detects TGF-beta and thereby activates subsequent cellular responses, could be used as a marker in the clinics to identify patient subgroups that may not benefit from hormone therapy alone and may require additional therapies,” said author Susann Busch, PhD, of Gothenburg University.

Dr. Busch and colleagues analyzed tumor samples of 564 pre-menopausal women who were enrolled in clinical trials from 1986 to 1991 and randomly assigned to either tamoxifen for two years (276) or no systemic treatment (288).

They found that among women who received tamoxifen and had estrogen receptor-positive tumors, those who had low TGFBR2 levels had a 73 percent lower recurrence-free survival rate compared to those with high levels of the protein.

In a follow-up series of laboratory experiments, the same researchers found that, in a drug-resistant cell line, there were low levels of TGFBR2 and abnormal pathway activation.