Luminal breast cancer metastases and tumor arousal from dormancy are promoted by direct actions of estradiol and progesterone on the malignant cells

Conclusions: We conclude that hormones promote development of multi-organ macrometastases in luminal disease. The metastases display a disturbing heterogeneity, containing newly emergent ER?PR? subpopulations that would be resistant to endocrine- and chemotherapies. Similar cells are found in luminal metastases of patients. Furthermore, lack of hormones is not protective. While no overt metastases form in ovx?d mice, luminal tumor cells can seed distant organs, where they remain dormant as micrometastases and sheltered from therapies, but arousable by hormone repletion. This has implications for breast cancer survivors or women with occult disease prescribed hormones for contraception or replacement purposes.
Source: Breast Cancer Research - Category: Cancer & Oncology Authors: Source Type: research