Cancers which develop in organs that are known to be under hormonal control, sometimes retain hormonal dependency. Withdrawing the source of the hormone in some such cases, lessens the growth of cancer. Cancers of the breast, prostate, uterus and thyroid are the ones amenable to hormonal treatment.
Previously, the adrenal glands or the pituitary gland were removed surgically for this purpose. But now the same effect is produced by medical rather than surgical means. Cancer response to Tamoxifen and Aminoglutethamide may take 6 to 12 weeks to manifest. Hence, it is necessary to wait for this period before making decisions about further management.
Androgen, the male sex hormone, may produces response in about 20 per cent of patients with breast cancer, particularly in postmenopausal women with bone metastasis. Oestrogen the female sex hormone is useful in the palliation of prostate cancer.
Some cancers of the thyroid remain under the influence of thyroid-stimulating hormone (TSH) and the administration of thyroid hormones may be useful as a result of its inhibiting pituitary secretion of TSH.
The major advantage of hormonal therapy over chemotherapy is that the side-effects are usually less severe than those associated with cytotoxic drugs. Tamoxifen rarely causes toxicity but aminoglutethamide can cause drowsiness, depression and transient skin rashes in some patients. The use of oestrogen in elderly men with prostate cancer warrants special caution in view of its known propensity to aggravate the fluid retention that may be harmful to the patients also suffering from a heart disease.