About 40 percent of breast cancers are hormone responsive that is, their growth rate is altered by the presence or absence of the female hormones, estrogen, and progesterone. The hormone responsiveness of each breast cancer should be determined by estrogen and progesterone receptor tests at the time of the initial biopsy, as described previously.
Of patients whose tumors respond to estrogen, two thirds will benefit from hormone therapy, which may involve either the elimination or addition of estrogen. Two key factors in hormone therapy are the menopausal status of the patient and the effect of hormones on the cancer. Some breast cancers are stimulated by hormones; hormonal manipulation often produces a remission in these cancers, especially if they have spread to distant organs.
The first step in hormonal manipulation usually involves eliminating estrogen and other female sex hormones. In the past this usually meant removal of the ovaries in premenopausal women, and sometimes the adrenal glands and pituitary as well. The ovaries may be removed surgically or exposed to radiation, but today a more common approach is to use drugs that either block the action or halt the production of the hormone. In some instances surgical removal of other hormone-producing glands, specifically the adrenals and the pituitary, still may be recommended in advanced cancer. Removal of the adrenal glands, which rest, atop the kidneys, eliminates androstenedione, a male hormone that post-menopausal women convert to estrogen. The adrenal glands can be removed at the same time as the ovaries, or afterward if the cancer, progresses. After menopause the removal of the adrenal glands alone leaving the ovaries may reduce bodily estrogen enough to slow the growth of estrogen dependent tumors.
The pituitary gland controls the ovaries and the adrenal glands; it also controls the milk glands in the breast by producing prolactin, a hormone that may also increase the growth of breast cancers. The pituitary is located in the center of the skull, behind the nose, and is usually removed by surgery through the roof of the mouth and nasal passages. The operation is called a hypophysectomy.
After adrenalectomy or hypophysectomy, the patient will need daily doses of cortisone to continue normal bodily functions. In addition, fludrocortisone (Florinef) may be necessary to regulate salt processing; pitressin may be given to conserve water. Women whose pituitary or adrenal glands have been removed should carry medical identification bracelets and information on emergency treatment for their condition at all times.