This is a systemic treatment modality when formation or conversion of female sex hormones is blocked at some biochemical stage with special medications. In general, this type of treatment can be considered targeted therapy, one of the first of its kind by the way. At the end of 19th century George Beatson noticed that changes of endocrine profile in patients with breast tumors led to changes in the tumor development and occasionally – reduced metastatic disease as well. The discovery of estrogen receptors on the surface of breast tumor cells in the 1960s explained why estrogen deprivation (blocking estrogen production) or blocking estrogen receptors, affects a large number of breast tumors. Nowadays, according to the research, around 80% of breast tumors have positive estrogen receptors while 65% have positive progesterone receptors.
Considering such prevalence of hormonal receptors among the breast tumors, hormonal therapy plays one of the key roles in the integrated breast cancer treatment.
This stage is usually the final and the longest one in the patient’s long journey to recovery.
According to their mechanism of action, hormonal drugs used in the treatment of breast tumors are divided into:
- Selective estrogen receptor modulators;
- Aromatase inhibitors, which in turn are divided into steroidal and non-steroidal;
- Estrogen receptor suppressor;
- LHRH agonists (of luteinizing hormone – releasing hormone).
Hormonal medications are usually prescribed as monotherapy except for aromatase inhibitors – in premenopausal patients they should be combined with LHRH agonists to suppress ovarian function. LHRH agonists themselves cannot be prescribed alone because they simply will not work this way.
In the case of disseminated metastatic hormone-dependent breast tumor it can be used as a separate kind of treatment or in combination with targeted drugs – at the moment it is a standard of the first line of therapy.