Some glands in the body’s endocrine system produce chemical agents called hormones (Eg. Pituitary, pancreas, adrenal). They reach all parts of the body by travelling through the bloodstream and then coordinate bodily functions and functions of a host of organs. They also regulate all cell functions in the body. Some hormones are testosterone, estrogen, thyroid hormone, insulin, epinephrine, cortisol, etc.
Based on recent research, hormones are believed to help some particular types of cancers grow. Hormone therapy relies on blocking those hormones and thus checks cancer.

The blocking of hormonal function can be done in various ways:

(i) Block hormone action: Cells have active sites called receptors on their cell wall surface where hormones bind and control cell activity. These receptors can be blocked by some other compound which has no controlling action and would thus stop hormone action. This occupancy of the hormone sites does not allow the hormone to interact with the cell.

(ii) Prevention of hormone production: Medication can be provided which reduces gland functions or surgery can be performed to simply remove the gland producing the hormone. Testosterone production, thus, can be decreased by removing the testes glands.

(iii) Change cell receptor shapes: With a changed shape, the hormone no longer recognized the cell and thus can not act, leaving it to slowly decompose and die.

Through several clinical trials, scientists have established that hormone therapy is effective in case of breast and prostate cancers, hence these are the forms where it is mostly used. Research is also being undertaken to measure its effectiveness in other forms of cancer.
It can be given in the following ways:
(i) Orally: This involves taking in of the medicine through the mouth

(ii) Subcutaneous(under the skin) or intramuscular(in the muscle) injections can be given

(iii) Surgical intervention, for example removing glands associated with production of the particular type of hormone.

Most people believe that hormone therapy is less effective or useful than other traditional forms such as chemotherapy. This belief has been totally shattered in case of breast or prostate cancers. It is widely considered a systematic therapy which implies that it travels all through the body unlike other local treatments like radiation therapy or surgery.

Like all other therapy forms, hormone therapy has some side-effects. These are mostly caused by hormone depletion leading to loss in the function that hormone performed. These can be quite like menopause for women; the only difference being that menopause is caused when the body naturally loses the ability to produce estrogen. The side effects may include – night sweats, hot flashes, vaginal dryness, weight gain and headaches. Nausea, hair thinning or loss, joint pain, muscle aches and also risk of uterine/endometrial cancer and blood clots may be reported.

In men, these effects might be hot flashes, breast tenderness, tiredness, loss of sex drive, nausea and impotence. Such a decrease in natural hormone production could also put people at a much higher risk for osteoporosis. To negate this side effect, Bisphoshonate might be given.

Even then, there is no sue way of knowing whether a particular type of therapy is working for you. It all depends on the type of cancer you have. Periodic radiology studies such as PET scans, MRIs and CT scans could give you a fair idea by measuring changes in tumor size. This is done through the blood by tumor markers. This may be also be gauged from the fact that the patient’s symptoms are decreasing. This can be discussed with a registered practitioner.