Cyclin D1 expression and early breast cancer recurrence following lumpectomy and radiation

Purpose: The purpose of this study was to determine the prognostic signific ance of cyclin D1 (cycD1) levels in ipsilateral breast tumor recurrence (IB TR) following lumpectomy and radiation therapy. Methods and Materials: A total of 98 patients (49 patients with IBTR and 49 matched cases without IBTR) selected from our conservatively treated breas t cancer population served as the patient population for the current study. All patients were treated with lumpectomy followed by radiation therapy to the intact breast to a total median dose of 64 Gy, The patients were follo wed in our clinic with a median follow-up of 13 years, Immunohistochemical analysis of cycD1 in these 98 early-stage breast cancer patients was perfor med using a polyclonal antibody generated against the human cycD1 protein. All clinical, pathologic, and molecular variables were entered into a compu terized data base for statistical analysis. Results: Low levels of immunohistochemically detected cycD1 protein correla ted with IBTR (p = 0.001), but there was no association between cycD1 prote in levels and metastatic disease, axillary lymph node involvement, distant disease-free survival (DDFS), and overall survival (OS), Subgroup analysis revealed that for early breast tumor relapses (within 4 years of initial br east tumor diagnosis), low levels of cycD1 were associated with IBTR (p = 0 .001). but cycD1 expression was not prognostic for IBTR from breast cancer patients with late relapses (p = NS). Conclusion: These studies provide in vivo evidence for the prognostic and b iologic significance of cycD1 expression in determining response to radiati on therapy in breast cancer patients. (C) 2000 Elsevier Science Inc.