A CLINICOPATHOLOGICAL STUDY ON OVEREXPRESSION OF CYCLIN D1 AND OF P53IN A SERIES OF 248 PATIENTS WITH OPERABLE BREAST-CANCER

Overexpression of cyclin D1 is frequently found in various types of hu man rumours and results from clonal rearrangement and/or amplification involving chromosomal region 11q13. In order to evaluate the patholog ical relevance of cyclin D1 overexpression in human breast cancer, we generated a polyclonal antiserum against the carboxy-terminal part of the cyclin D1 protein. After affinity purification, the antiserum spec ifically detected overexpression of cyclin D1 in formalin-fixed, paraf fin-embedded tumour material also. The intensity of the nuclear staini ngs was, in general, proportional to the degree of cyclin D1 amplifica tion. We did not encounter significant variability of staining within individual tumours with overexpression of cyclin D1. Overexpression of cyclin D1 appeared to be associated with oestrogen receptor-positive breast rumours, but not with any other clinicopathological parameter t ested. Overexpression of cyclin D1 was not of prognostic value for rec urrence or survival in a consecutive series of 248 operable breast can cer patients (stage I and II). Overexpression of p53 was also not of p rognostic significance in this series, but was associated with undiffe rentiated histology and oestrogen receptor-negative breast tumours, as has been reported previously by others. A high proportion of breast t umours with a low grade of malignancy in this series of operable breas t cancer patients may explain discrepancies concerning the prognostic value of amplification and of overexpression of cyclin D1.