Patients with hormone receptor-positive tumors may benefit from an endocrine (anti-hormonal) therapy. This mainly affects cancers of the breast and prostate.
Basically, there are only two types of hormone therapy: hormone blocking and hormone withdrawal. During pure hormone blocking therapy, the patient takes a drug which inhibits the effects of the body’s own hormones on the cancer cells, but has no effect on the body’s capacity to produce hormones in itself. Alternatively, hormone withdrawal therapies exist. By administering aromatase inhibitors, for example, this therapy suppresses the body’s own production of the sex hormones.
Response of circulating tumor cells during hormone blockade
The first measured value of the maintrac® cell count is always used as a basis value, which has little significance when considered alone. Only the cell count progression, which can be seen after further measurements are taken, can be interpreted.
Adjuvant hormone blockade
Decreasing cell counts
During hormone blocking therapy, the cell count is often seen to decrease steadily, but very slowly over a period of many years. Not all cells are destroyed, but many are rendered temporarily inoperative (dormancy). Continuation of therapy is recommended for this reason, in order to prevent any micro-metastases from forming.
Constant cell counts
If the cell count remains unchanged over the course of adjuvant hormone blocking therapy, this is not necessarily a cause for concern. On the contrary, an unchanged value over the course of many years may be associated with a good prognosis.
Fluctuating cell counts
Irregular intake of medication may lead to fluctuations in the cell count progression of female patients undergoing antihormonal therapy.
Fluctuating cell numbers in female patients who have not yet reached menopause may also be caused by an insufficient inhibition of estrogen production.
Increasing cell counts
If the cell count increases slowly and steadily over a long-time period, this may indicate a lacking effectiveness of the therapy. The treatment should be modified.
Response of circulating tumor cells after maintenance therapy
Antihormonal therapies are associated with severe side-effects in some cases. For this reason, many breast cancer patients question whether extended use of antihormonal therapies are necessary, or beneficial. maintrac® can check to what extent patients benefit from continuing therapy, and so can help when make decisions in this regard.
Dynamic in cell count over long-term observation
Decreased or constant cell count
If the number of cells drops after discontinuation of hormone therapy, or if the cell count remains constant, then this indicates positive progress. Further hormone treatments may not necessarily be required, but the subsequent dynamics in cell count should be monitored.
Increase in cell count
If an increase in circulating tumor cells is seen after discontinuation of therapy, then patients should consider resuming the antihormonal therapy. It has been shown that there is a significant correlation between the increase in cell count after discontinuation of hormone therapy and rate of relapse in hormone receptor-positive breast cancer patients.
[Pachmann, Katharina & Schuster, Stefan: Brustkrebsüberwachung nach Ende der Hormontherapie:Bieten zirkulierende epitheliale Tumorzellen eine Entscheidungshilfe? gyne 36. Jg., 28-32 (2015)]