Menopause and breast cancer: addressing the secondary health effects of adjuvant chemotherapy

Addressing the Unintentional Consequences of Cancer Therapy With Novel Integrative Therapeutics

There are 15.5 million cancer survivors in the United States because of, in part, improvements in therapy. As a result, there will be an increased burden of long- and late-term complications of cancer care, such as metabolic alterations. These metabolic changes will include alterations in bone resorption, obesity, hypercholesterolemia, and diabetes mellitus. The majority of cancer treatment-related toxicities have focused on endocrine therapy; however, chemotherapy and supportive medications, such as steroids, contribute to the development of these disorders. Because of the chronicity of these metabolic changes and their impact on morbidity, cancer risk, and outcomes as well other negative effects, including musculoskeletal pain and vasomotor symptoms, alternative strategies must be developed. These strategies should include nonpharmacologic approaches. Here, we summarize metabolic changes secondary to cancer care and integrative approaches to help alleviate therapy-associated toxicities.

Bone mineral density in women treated for various types of gynecological cancer

AIM

Patients with gynecologic cancer frequently experience bone loss due to cancer treatments, including bilateral oophorectomy, chemotherapy and radiotherapy. This study evaluated treatment-associated changes in bone mineral density (BMD) in women with gynecologic cancer and compared changes among patients with different types of gynecologic cancer.

METHODS

BMD of the lumbar spine and femur was retrospectively analyzed using dual-energy X-ray absorptiometry in 118 women who underwent treatment for gynecological cancers and 132 women without gynecologic cancers. The cohort included 55 women with cervical cancer who underwent surgery followed by adjuvant chemotherapy and/or radiation therapy, 33 with endometrial cancer (EC) who underwent surgery followed by adjuvant radiation therapy and 30 with ovarian cancer who underwent bilateral oophorectomy followed by adjuvant platinum-based chemotherapy. Lumbar spine and femoral neck BMD were assessed at baseline and 12 months after treatment. Areal BMD, expressed as grams of mineral/cm² scanned, was compared with that in young healthy women (T-score).

RESULTS

Demographic characteristics and pretreatment BMDs, including T-scores, did not differ among cancer types. After adjustment for factors that can affect T-score, cancer type affected change in T-score 12 months after treatment. After adjustment for pretreatment age, parity, BMI and T-score, T-score 12 months after treatment was significantly lower in the EC than in the other groups.

CONCLUSIONS

Women treated for gynecological cancer, particularly those with EC who undergo bilateral oophorectomy followed by adjuvant radiation therapy or chemotherapy, should be managed in a timely manner to prevent or minimize bone loss.

Bone health in adult cancer survivorship

Optimizing health outcomes, including prevention of osteoporotic fractures, is essential for promoting the well-being of the growing number of cancer survivors. Medical providers who participate in the care of cancer survivors should be aware that various cancer treatments may cause bone loss, which can increase the risk of subsequent of osteoporosis. Healthy bone remodeling is a balanced and dynamic equation between new bone formation and bone resorption. Aging, natural menopause, and cancer treatments such as surgical oophorectomy, gonadotropin-releasing hormone agonists, chemotherapy-induced ovarian failure, androgen deprivation therapy, and aromatase inhibitors can all promote bone loss. The WHO Fracture Assessment Tool can be used as a clinical aid to assess an individual's osteoporotic fracture risk, with or without bone mineral density measurements obtained from dual-energy x-ray absorptiometry. Preventative strategies include adequate calcium and vitamin D supplementation and modifying risk factors such as alcohol intake, tobacco use, and lack of exercise. Bisphosphonate therapy and rank-ligand monoclonal antibody therapy are the most commonly used agents for management of bone loss resulting from cancer treatment. This review will summarize the mechanisms by which cancer treatments cause bone loss as well provide screening and treatment recommendations for the management of bone loss.

Breast cancer treatment and ovarian failure: risk factors and emerging genetic determinants

Most premenopausal women diagnosed with primary breast cancer receive adjuvant chemotherapy, and many experience chemotherapy-induced ovarian failure (CIOF). CIOF is associated with menopausal symptoms, fertility concerns and long-term implications including bone loss. Ironically, CIOF might confer a disease-specific benefit to women whose breast cancers express hormone receptors. Risk factors of CIOF include the woman's age at the time of therapy, and the type, dose and schedule of chemotherapy. Because inherited genetic factors have an important role in determining who will experience CIOF, genetic testing has the potential to provide optimal counselling about risks and possible interventions.

Quality of life in the intergroup exemestane study: a randomized trial of exemestane versus continued tamoxifen after 2 to 3 years of tamoxifen in postmenopausal women with primary breast cancer

PURPOSE

To compare and describe the quality of life (QOL) of women allocated to tamoxifen or exemestane within the Intergroup Exemestane Study (IES).

PATIENTS AND METHODS

Postmenopausal women with primary breast cancer who were disease free after 2 to 3 years were randomly assigned to switch from tamoxifen to exemestane or continue with tamoxifen until 5 years of treatment were completed. A subset of IES centers participated in a QOL substudy. The Functional Assessment of Cancer Therapy-Breast (FACT-B) and endocrine subscale (ES) were administered before random assignment and at predefined follow-up times. The primary end point was the FACT-B composite Trial Outcome Index (TOI). Secondary end points included total FACT-B+ES score, total ES score, and severity of individual endocrine symptoms. This analysis reports QOL up to 24 months.

RESULTS

Five hundred eighty-two patients from eight countries were enrolled onto the substudy. Completion and return of questionnaires was excellent, with 85% available for analysis. QOL was generally good and stable over 2 years, with no clinically meaningful differences found between groups in TOI or ES. Prevalence of severe endocrine symptoms at trial entry was high for vasomotor complaints and sexual problems, which persisted for both groups during the study. No significant differences between groups were seen for any endocrine symptoms apart from vaginal discharge, which was more pronounced with tamoxifen (P < .001).

CONCLUSION

The switch from tamoxifen to exemestane neither increased nor decreased endocrine symptoms present after 2 to 3 years of tamoxifen; the switch also did not initiate significant reports of new symptoms. Results indicate that the clinical benefits of exemestane over tamoxifen are achieved without significant detrimental effect on QOL.

Breast cancer, menopause, and long-term survivorship: critical issues for the 21st century

Breast cancer accounts for 33% of all incident cancers in women in North America, and there are an estimated >2 million breast cancer survivors in the United States today. Ovarian hormones are intimately involved in the initiation and promotion of breast cancer development, with targeted endocrine therapies being the most widely used as anticancer treatment. It is not surprising that these treatments frequently cause persistent menopausal symptoms in breast cancer survivors. In addition, adjuvant chemotherapy often induces premature menopause in younger patients with breast cancer. Some women at high risk for the development of breast cancer (e.g., precancerous breast disease, carriers of deleterious hereditary predisposition genes) experience vasomotor symptoms as a result of tamoxifen therapy or preventive oophorectomy. Clinical management of menopausal symptoms in these settings is complicated by the relative prohibition of hormonal therapies and the fact that breast cancer-directed therapies often exacerbate these menopausal symptoms. Thus, this special population of women requires unique management strategies and deserves separate consideration.

Fertility in female cancer survivors: pathophysiology, preservation and the role of ovarian reserve testing

The improved long-term survival of adolescents and young women treated for cancer has resulted in an increased focus on the effects of chemotherapy on ovarian function and its preservation. These women may seek advice and treatment regarding their reproductive status, including ways of preserving their fertility and preventing a premature menopause--factors that can have a profound impact on their quality of life. This article comprehensively reviews ovarian reserve testing (ORT) in general. Special emphasis is placed on patients with cancer, including the pathophysiology of gonadal damage following chemotherapy, fertility preservation and the potential role of ORT. Baseline parameters of ovarian reserve [FSH LH, estradiol, inhibin B and anti-Mullerian hormone (AMH)] have not yet performed sufficiently well in predicting poor outcome in assisted reproduction, but biochemical markers of ovarian reserve appear to be better than chronological age. Inhibin B and AMH show potential for future use. Dynamic testing appears to show much promise, especially stimulated levels of inhibin B and estradiol. The most promising tests of ovarian reserve are the biophysical markers, where total antral follicle count was found to be most discriminatory followed by ovarian volume. Combination of biochemical, biophysical and clinical markers of ovarian reserve may also improve predictive capacity. However, there is a lack of data pertinent to ORT in cancer. As yet there is no single clinically useful test to predict ovarian reserve accurately. Patients with cancer represent a distinct cohort who have particular concerns about their future fertility and the possibility of a premature menopause, they can benefit greatly from knowledge of their functional ovarian reserve. Large, prospective, randomized, adequately controlled studies specific to different geographical areas are required in a control population of comparable reproductive age to determine the potential role of ORT in clinical practice.

Osteopenia and osteoporosis in women with breast cancer

Osteopenia and osteoporosis are prevalent in women. Epidemiologic studies show that the risk of breast cancer is greater in postmenopausal women with higher bone mineral density (BMD). Standard treatments for breast cancer such as adjuvant chemotherapy or hormonal therapy can increase bone loss, and hence may increase the risk of osteoporosis. Premenopausal women treated with standard adjuvant chemotherapy frequently develop permanent ovarian failure, or early menopause. Ovarian failure is associated with accelerated bone loss, and bisphosphonates may mitigate this bone loss in women treated with adjuvant chemotherapy. Tamoxifen preserves BMD in postmenopausal women; however, in premenopausal women tamoxifen may increase bone loss. Anastrazole, an aromatase inhibitor, is approved for adjuvant treatment of postmenopausal women with early-stage, estrogen receptor-positive breast cancer. With a follow-up duration of less than 5 years, anastrazole-treated women experience increased fractures relative to those treated with tamoxifen. The management of osteopenia and osteoporosis in women with breast cancer generally does not differ from women without breast cancer. Adequate dietary calcium and vitamin D intake, encouraging weight-bearing exercise, and counseling about the relationship between smoking and alcohol and bone loss are all prudent recommendations for overall health and may lessen bone loss and the risk of subsequent osteoporosis. BMD should be measured in women with chemotherapy-induced ovarian failure, and in those on aromatase inhibitors. Bisphosphonates reduce the bone loss associated with chemotherapy-induced ovarian failure, and clinical trials evaluating third-generation bisphosphonates in women with chemotherapy-induced ovarian failure are underway. As many women with breast cancer will be long-term survivors, increasing recognition of maintaining skeletal health is important.

Systemic therapy

A large body of data on systemic therapy has been presented and published in the past year, including new information on primary risk reduction, patient selection for adjuvant systemic therapy, and anthracycline-analogs. New data on ongoing adjuvant trials (including taxane studies), unpublished updates from the fourth Oxford Overview in September 2000, and provocative data on ovarian ablation were important features of the November 2000 National Institutes of Health Consensus Development Conference on Adjuvant Therapy for Breast Cancer. Important new data on anti-estrogen therapy, including aromatase inhibitors and pure antiestrogens, further expand the role of the oldest targeted breast cancer therapy. Trastuzumab and other novel compounds are being investigated as single-agents and in combination with conventional systemic approaches. Discussions on the long-term effects of adjuvant therapy have taken center stage also. These and other important ongoing developments since 2000 are examined in this review article.