Personalised tamoxifen treatment
Patients with estrogen receptor positive tumours account for about 3/4 of all cases. These patients receive anti-estrogen adjunctive therapy for 5-10 years to reduce the risk of recurrence. Tamoxifen has a central role in the anti-estrogen treatment of breast cancer, especially for premenopausal patients.
The individual (genetically determined) metabolism of tamoxifen in the liver leads to very different serum levels of the active forms of tamoxifen. The active forms (active metabolites) are 100x more effective at stopping cell division of any remaining breast cancer cells after surgery. Dr./postdoc Thomas Helland has published a study indicating that patients who have low levels of active tamoxifen metabolites probably have poorer long-term survival than patients with higher levels. The PBCB material will be used to validate this finding, when the follow-up time is long enough. Such measurements may give the clinician a tool to optimise endocrine adjuvant therapy by, for example, giving patients an appropriate amount and type of anti-oestrogen.