Stromal Platelet-Derived Growth Factor Receptor-Beta Expression Biomarker for Early Breast Cancer
Posted: Wednesday, August 18, 2021
According to findings presented in Clinical Cancer Research, high stromal platelet-derived growth factor receptor-beta (PDGFRb) expression may prove to be a novel biomarker when identifying ductal carcinoma in situ (DCIS) in patients. Arne Östman, PhD, of the Karolinska Institutet, Stockholm, and colleagues also noted that their findings imply previously unrecognized fibroblast-mediated modulation of radiosensitivity in DCIS, which should be further explored.
“It is well known that the benefits of radiotherapy are individual, so we need to find predictive markers that can be used to avoid unnecessary or ineffective radiotherapy,” said coauthor Fredrik Wärnberg, MD, PhD, of the University of Gothenburg, Sweden, in a Karolinska Institute press release.
The authors used samples from the national Swedish randomized DCIS trial, which enrolled 1,046 women who were diagnosed with DCIS between 1987 and 1999 and received breast-conserving surgery. The samples in the latest trial were subjected to immunohistochemistry analysis for expression of stromal PDGFRb.
The analysis showed that a patient’s stromal PDGFRb expression score was predictive for radiotherapy benefits in regard to ipsilateral breast events. Patients with low stromal platelet-derived growth factor receptor-beta expression scores had a strong benefit from radiotherapy regarding risk for ipsilateral breast events (hazard ratio = 0.23), with an absolute risk reduction of 21% at 10 years.
There was no significant risk reduction by radiotherapy found in patients with high expression scores of stromal PDGFRb (hazard ratio = 0.83). The radiotherapy response–predictive effect of stromal PDGFRb expression was “equally strong” in analysis for in situ and invasive ipsilateral breast events when analyzed separately.
Disclosure: For full disclosures of the study authors, visit clincancerres.aacrjournals.org.