Molecular events immediately after chemotherapy may affect breast cancer response to treatment. Previous in vivo data from our institution suggested that the degree of therapy-induced apoptosis, measured within 72 hours after treatment, correlated with breast cancer response to taxane chemotherapy. We performed this study to investigate whether apoptosis-related biomarkers can be used to predict treatment response in breast cancer patients treated with neoadjuvant chemotherapy. Methods: Biomarker data were available on 25 out of the 30 patients with locally advanced breast cancer who underwent serial core biopsies of the primary tumor at 3 time points: pretreatment, 24 hours after chemotherapy and 48 hours after chemotherapy. The neoadjuvant chemotherapy was docetaxel/ doxorubicin in 16 patients, single-agent paclitaxel in 8 patients, and 5-flourouracil, doxorubicin, cyclophosphamide in 1 patient. Bcl-2, bax, and p53 were studied with immunohistochemistry using semi-quantitative values. Results: After the neoadjuvant chemotherapy. 4 patients had a pathological complete response (CR) of the primary tumor, 7 additional patients had disease measuring <1 cm, and the remaining 14 had >1cm of residual disease. There was no correlation of response to pretreatment measurements of p53, bcl-2, or bax. However, a decrease in bcl-2 expression after chemotherapy relative to the expression from the pretreatment sample correlated with a favorable pathological response (CR versus non-CR, p=0.010 - Fisher's exact test). (CR + <1cm versus >1cm, p=0.026). There was no relationship between the serial measurements of bax and disease response. Conclusion: We demonstrated that a decrease in bcl-2 expression immediately after treatment predicts response of breast cancer to neoadjuvant chemotherapy. These data suggest that apoptosis may play an important role in determining breast cancer response to chemotherapy.
|Original language||English (US)|
|Number of pages||1|
|Journal||Breast Cancer Research and Treatment|
|State||Published - 2001|
ASJC Scopus subject areas
- Cancer Research