Tumor Biomarker May Help Predict Breast Cancer Survival
Low expression of cell cycle regulatory protein p27 associated with poorer five-year survival
WEDNESDAY, Dec. 6 (HealthDay News) -- In women with newly diagnosed moderate-risk breast cancer who receive doxorubicin plus cyclophosphamide adjuvant chemotherapy, low expression of the cell cycle regulatory protein p27 is associated with poorer five-year survival in hormone receptor-positive patients, according to a study published in the Dec. 6 issue of the Journal of the National Cancer Institute.
Peggy Porter, M.D., of the Fred Hutchinson Cancer Research Center in Seattle, and colleagues used tissue microarrays to evaluate the expression of p27 and cyclin E by immunohistochemistry in tumor tissue from 2,123 patients.
Lower p27 expression was associated with worse overall survival (unadjusted hazard ratio, 1.50) and disease-free survival (unadjusted HR, 1.31). In women with hormone receptor-positive tumors, the researchers found that those with low p27 expression had poorer five-year survival than those with high p27 expression (85 percent versus 91 percent). In women with hormone receptor-negative tumors, no association between p27 expression and decreased survival was found. Cyclin E did not have a statistically significant association with overall or disease-free survival.
"Our results have not yet been validated in other studies, so they still need to be confirmed before establishing p27 expression as a prognostic factor in patients treated with chemotherapy," the authors write."
Two of the study's 14 authors are named on patents related to this technology.