The influence of hormone replacement therapy on the pathology of breast cancer.

AIM OF THE STUDY To assess whether the pathological characteristics of breast carcinomas arising in post-menopausal women who ever used hormonal replacement therapy (HRT) differ from those of post-menopausal patients who never used HRT. MATERIALS AND METHODS Six hundred and forty three consecutive breast cancer patients were entered in a case control-study. Cases were represented by 111 breast cancer patients who had used or were using HRT at the time of diagnosis, while the remaining 532 patients who never used HRT were chosen as controls. RESULTS Tumour diameter was smaller in HRT users (17.6 vs 22.1 mm; p=0.002) and tumours of lobular histology were almost twice more frequent among HRT users as in 'never users' (21 vs 12%; p=0.01). No differences were found in grading, hormonal receptor status and axillary nodal status. The expression of c-erb B-2, p53, Ki67 and PS2 measured by immunohistochemistry was similar in the two groups. CONCLUSIONS Our findings suggest that HRT use may modify the pathological presentation of breast cancer. Further studies are indicated, while other clinical-pathological characteristics did not differ according to HRT use.