Hormone replacement therapy and risk for breast cancer

Prophylactic surgery in women with a hereditary predisposition to breast and ovarian cancer

PURPOSE

To review the published literature on the efficacy and adverse effects of prophylactic mastectomy (PM) and prophylactic oophorectomy (PO) in women with a hereditary predisposition to breast and ovarian cancer and to provide management recommendations for these women.

METHODS

Using the terms "prophylactic," "preventive," "bilateral," "mastectomy," "oophorectomy," and "ovariectomy," a MEDLINE search of the English-language literature for articles related to PM and PO was performed. The bibliographies of these articles were reviewed to identify additional relevant references.

RESULTS

There have been no prospective trials of PM or PO for the reduction of breast cancer or ovarian cancer incidence or mortality. Most of the available retrospective studies are composed of women who had surgery for a variety of indications and in whom genetic risk was not well characterized. However, some reports in women at increased risk of breast or ovarian cancer have shown that PM and PO can reduce cancer incidence.

CONCLUSION

Interest in and use of PM and PO are high among physicians and high-risk women. PM and PO seem to be associated with considerable reduction in the risk of breast and ovarian cancer, albeit incomplete. The surgical morbidity of PM and PO is low, but the complications of premature menopause may be significant, and few studies address quality-of-life issues in women who have opted for PM and PO. Management recommendations for high-risk individuals are presented on the basis of the available evidence.

Breast carcinoma etiology: current knowledge and new insights into the effects of reproductive and hormonal risk factors in black and white populations

BACKGROUND

A crossover in breast carcinoma incidence at ages 45-49 years has been observed between black and white women, with blacks experiencing higher incidence at younger ages and lower incidence after age 50 years. Can this phenomenon be partially explained by the differences in the distributions of reproductive risk factors? This article focuses on the effects and distributions of age at first full term pregnancy (FFTP), parity, and oral contraceptive (OC) use in younger versus older and black and white populations. Effects of hormone replacement therapy (HRT) are also summarized.

METHODS

A literature review was conducted and information integrated on the effects and distributions of reproductive and hormonal risk factors in black and white populations, the crossover effect of parity, and the Pike model of "breast tissue age."

RESULTS

Overall, early age at FFTP and higher parity decreased risk for both races. Distributions of age at FFTP and parity varied widely between the two races. Based on the effects and distributions of age at FFTP and parity, the authors formulated the hypothesis that a crossover in incidence curves between the two races would be expected, rather than be considered an anomaly. Regarding OC use, generally a stronger increase in risk was observed for younger women than for older women. Regarding HRT, a recent meta-analysis observed an increased risk of 1.35 for 5 years of use or more.

CONCLUSIONS

To promote public health in diverse populations, and to provide further insight into breast carcinoma etiology, research needs to focus on multicultural differences and similarities in the relation of hormonal risk factors and breast carcinoma.

The menopause

Menopause is diagnosed after 12 months of amenorrhoea resulting from the permanent cessation of ovarian function. The mean age at menopause is 51 years. The perimenopause, a time of changing ovarian function, precedes the final menses by several years. The physiology and clinical manifestations of this transition to menopause are not well understood; however, some symptoms, such as hot flashes, certainly begin in the perimenopause. Causal associations between menopause and several symptoms and diseases are proposed. The evidence for these associations varies and is reviewed. Hormone replacement therapy can be directed at symptom relief or at prevention or treatment of chronic diseases. Doses and routes of hormone replacement therapy vary by indication. Complications of hormone replacement therapy depend on the regimen used. Knowing the expected vaginal bleeding pattern for each hormone replacement therapy regimen is important, since unexpected bleeding may signal endometrial hyperplasia. Postmenopausal hormone therapy is a complex intervention that produces positive and negative specific health effects. Overall, based on observational studies, postmenopausal women who use hormones have a 30-50% lower all-cause mortality rate than those who do not use hormones. It is important to recognise that the value that individual women place on various health outcomes associated with hormone replacement therapy may differ. Thus, the decision to use hormone replacement therapy should be made jointly by each woman and her health-care provider, after careful consideration of possible benefits, risks, and her personal preferences.

Postmenopausal hormone replacement therapy and cancer of the female genital tract and breast

Taking into account data from recent case-control and cohort studies, this review addresses anew the controversial issue of a possible relationship between hormone replacement therapy and an increased risk of female cancer. The adequate addition of a progestogen reduces considerably the significantly increased risk of endometrial cancer seen in current and in past long-term estrogen replacement therapy (ERT) users. However, a small risk increase might still be present with combined estrogen-progestogen replacement therapy (EPRT), and with low-dose continuous combined treatment. Whether long-term hormone replacement therapy increases the risk of breast cancer remains controversial. All four recent case-control studies report a small, marginally significant risk increase of about 20-30%, while two recent cohort studies are very reassuring. Sequential addition of a progestogen does not seem to influence breast cancer risk. Unfortunately, no data are available on the both practically and theoretically interesting option of continuous combined hormone replacement therapy. It can be concluded from the present data that hormone replacement therapy can be safely prescribed for periods of less than five years to women with climacteric symptoms. Short-term hormone replacement therapy for climacteric complaints in women who have been treated for the above-mentioned cancers should not be considered to be absolutely contraindicated as the available but scanty new data do not indicate any detrimental effect in such women.