ABSTRACT PURPOSE: to evaluate the changes in the cell phenotype determined by primary chemotherapy. METHODS: we evaluated the expression of proliferating cells of nuclear antigen (PCNA) and the estrogen (RE) and progesterone (RP) receptors in 17 stage II breast cancer patients before and after chemotherapy by immunohistochemistry. The values were compared with menopausal status, tumoral clinical response and with axillary lymph node status. RESULTS: there was a significant decrease in the average index of anti-PCNA-stained cells before (time A) and after (time B) chemotherapy (p=0.041). Responder patients displayed a significant decrease in PCNA levels [time A=53.1 and time B= 30.7 (p=0.011)]. A similar trend was observed in patients with histologic grade GII/GIII [time A=63.1 and time B=38.7 (p=0.049)]. There was no significant difference in PCNA expression regarding menopause status and axillary lymph node involvement. There was a significant decrease in RE after chemotherapy in the premenopausal patients [time A=60.3 and time B=24.1 (p=0.027)] and in those who showed a therapeutic response [time A=59.1 and time B=37.9 (p=0.030)]. We observed a significant increase in RP after chemotherapy in the postmenopausal patients [time A=35.3 and time B=58.3 (p=0.023)]. There was no relationship between hormone receptors and axillary lymph nodes. CONCLUSIONS: the decrease in PCNA levels in patients with high histologic grade, in RE in premenopausal patients, and both, PCNA and RE, in the tumors with clinical response after chemotherapy shows that the drugs acted on proliferating cells, and therefore PCNA can be used as a parameter of treatment response.
Breast cancer; Chemotherapy; Proliferating cells of nuclear antigen; Hormone receptors
