Estrogen Priming to Increase the Efficacy of Adjuvant Chemotherapy in Operable Breast Cancer
Status:
Terminated
Trial end date:
2012-03-30
Target enrollment:
Participant gender:
Summary
One of the basic principles of cancer chemotherapy is that these drugs act exclusively or
mainly on cells in cycle. Estrogens have been shown to increase the fraction of breast cancer
cells in cycle. Tamoxifen on the other hand, decreases the proliferative fraction and has
been shown to negatively impact on the results of adjuvant chemotherapy in breast cancer when
given concomitantly. A number of previous studies have attempted estrogenic recruitment of
cancer cells (into cell cycle) to increase the efficacy of chemotherapy in locally advanced
and metastatic breast cancer. Although some studies showed an increase in response rates in
the recruitment arm, there was no benefit in time to progression or survival in any of the
studies. These results may have been due to the inadequate sample size of the studies and
advanced stage disease (with presumably higher fraction of inherently chemoresistant cells).
The present study is designed to test the hypothesis that estrogenic recruitment of
micrometastatic disease in operable breast cancer will increase the efficacy of standard
adjuvant chemotherapy after surgery. The intervention arm of the study will involve
administration of short duration estrogen prior to each cycle of adjuvant chemotherapy. The
end-points are disease free and overall survival.