Taking Nolvadex (Tamoxifen) for Breast Cancer and Having Hot Flashes?
Breast cancer, which is highly treatable by surgery, radiation therapy, chemotherapy, and hormonal therapy, is most often curable when detected in early stages.Pathologically, breast cancer is frequently a multicentric disease. However, clinical diagnosis of two or more primary cancers in a single breast is uncommon . Similarly, simultaneous bilateral breast cancer is unusual. It is more common in patients with infiltrating lobular carcinoma.
Increasingly, hormone replacement therapy (HRT) is prescribed for many postmenopausal women in the United States both to decrease acute menopausal symptoms and to promote long term health benefits.Neither pregnancy after breast cancer nor the use of oral contraceptive pills before a diagnosis of breast cancer has been shown to adversely impact survival when controlled for stage of disease. These findings provide the rationale for prospective clinical trials testing the impact of HRT on breast cancer recurrence and on the development of new tumors. Such research is planned in carefully selected women
with breast cancer at relatively low risk of relapse.
Tamoxifen is an adjuvant therapy option for both pre- and postmenopausal women with hormone receptor positive early-stage breast cancer.Tamoxifen belongs to a class of drugs known as selective estrogen receptor modulators. Tamoxifen blocks estrogen, a hormone that promotes the growth of breast cancer cells. Tamoxifen is sometimes called an anti-estrogen. It is the prototype for a growing class of compounds called selective estrogen receptor modulators (SERMs). More than 210,000 women in the United States will develop breast cancer. Approximately 70 percent of these cancers are fueled by estrogen, many of which are treated with tamoxifen, a drug designed to block the effects of estrogen in breast tissue.
The antitumor effects of tamoxifen are thought to be due to its antiestrogenic activity, mediated by competitive inhibition of estrogen binding to estrogen receptors. As a consequence, tamoxifen inhibits the expression of estrogen-regulated genes, including growth factors and angiogenic factors secreted by the tumor that may stimulate growth by autocrine or paracrine mechanisms. The net result is a block in the G1 phase of the cell cycle and a slowing of cell proliferation. Tumors may then regress because of this altered balance between cell proliferation and ongoing cell loss. Tamoxifen may also directly induce programmed cell death.
SERMs chemically resemble estrogen and trick the breast cancer cells into accepting it in place of estrogen. Unlike estrogen, however, they do not stimulate breast cancer cell growth.Tamoxifen helps reduce the chances that a woman will have a recurrence of breast cancer or develop a new cancer in the other breast. It may also slow the natural loss of bone density in postmenopausal women as they age.A characteristic that distinguishes these substances from pure receptor agonists and antagonists is that their action is different in various tissues, thereby granting the possibility to selectively inhibit or stimulate estrogen-like action in various tissues.
More than 50 percent of women entering into menopause know the feeling all-too-well. That sudden rush of uncomfortable and often embarrassing heat that seems to take over your body, causing your heart to race and your skin to redden.It's believed that estrogen production affects the part of the brain that controls the body's temperature. The body's "thermostat" prevents us from overheating or freezing in various environments.With menopause, there's a lack of estrogen that causes this thermostat to become irregular, which causes women to be substantially sensitive to temperature changes that would normally not bring about a sudden change in the body's temperature.
Hot flashes may act as positive sign for women taking drug treatment for early stage breast cancer, a new study suggests.
Researchers at the Moores Cancer Center at the University of California, San Diego analyzed data from 864 women with early stage breast cancer who were taking tamoxifen therapy. They found that those who reported having hot flashes were less likely (12.9 percent) to develop recurrent breast cancer than those who did not report hot flashes (21 percent).
The researchers also concluded that hot flashes were a stronger predictor of outcome than age, hormone receptor status, or stage of breast cancer at diagnosis. The findings were to be presented at the annual meeting of the American Society of Clinical Oncology, in Chicago.
"This study provides the first evidence that hot flashes may be an indicator of a better prognosis in women with early stage breast cancer. Our data support the possibility of a significant association between the hot flashes and disease outcome," senior author John P. Pierce, director of the Cancer Prevention and Control Program at the Moores Cancer Center, said in a prepared statement.
The researchers plan additional research to explore the relationship between hot flashes and breast cancer progression.
Vasomotor hot flashes occur commonly in menopausal women. In addition, they are the most frequent side effect associated with the antiestrogen drug tamoxifen1. The cause of vasomotor symptoms is not entirely understood. Study have hypothesized that throughout reproductive life physiologic levels of estrogen and progesterone maintain endogenous opioid peptide concentrations in the hypothalamus and brain stem. Declining estrogen levels at the time of menopause result in decreased endogenous peptide activity, with the release of noradrenergic activity from its usual inhibition. This noradrenergic hyperactivity leads to inappropriate activation of heat-loss mechanisms in the medial preoptic area. Hot flashes, which appear to coincide with increased concentrations of gonadotropin-releasing hormone, are the result.
The most common treatment for hot flashes in women is estrogen-replacement therapy, which may eliminate hot flashes altogether. However, many physicians believe that estrogen-replacement therapy is relatively contraindicated in patients with breast cancer because of the concern that it may stimulate growth of the tumor.
When used as adjuvant therapy for early stage hormone receptor positive breast cancer, tamoxifen is well-tolerated for 5 years. Evidence shows that taking it for 5 years significantly improves survival rates and reduces recurrence. Taking it longer appears to confer no additional advantages. Patients whose tumors are convincingly hormone receptor-negative do not benefit. Comparisons between tamoxifen and other SERMs used for adjuvant therapy are underway.Selective serotonin reuptake inhibitors or SSRI’s, are often used to treat hot flashes, a common side effect of tamoxifen.Side effects others include vaginal discharge, an increased chance of endometrial cancer and blood clots.