Hormones are compounds internally
secreted by a specific tissue/organ, transported by body fluids to another
tissue/organ (receptor), and affect the function of the receptive tissue/organ.
Most hormones exist naturally but some hormones can be synthesized.
For example, tamoxifen is a common
hormone treatment for breast cancer.
Also, a phase II clinical study suggested that the concomitant
administration of melatonin (a pineal hormone) and tamoxifen may induce tumor
regressions in metastatic breast cancer patients refractory to tamoxifen alone.
Fig.
1.14
Structure of tamoxifen
Certain breast cancer cells require
the activation of estrogen receptor to grow. Tamoxifen (Fig. 1.14) is first
metabolized by human cytochrome P450 and its metabolites then compete with
estrogen in binding to and inactivating estrogen receptor, thus hampering the
growth of the breast cancer cells.
Tamoxifen was approved by the FDA in
December 1977. It is currently used for
the treatment of both early and advanced estrogen receptor positive (ER+)
breast cancer patients. In June 1990, tamoxifen was approved
by the FDA for an additional use to help prevent the recurrence of breast
cancer wherein the cancer cells have not spread to the lymph nodes under the
arm.
© Jiajiu Shaw, 2019
Disclaimer: This blog is written solely for informational purposes. It does not constitute the practice of any medical, nursing or other medical professional health care advice, diagnosis, or treatment. All contents posted are extracted from the book, "SIDE EFFECTS OF CHEMOTHERAPY AND RADIOTHERAPY", prepared by Dr. Jiajiu Shaw, Dr. Frederick Valeriote, and Dr. Ben Chen
