Chemoprevention of breast cancer: implications for postmenopausal women

Risks, benefits, and effects on quality of life of selective estrogen-receptor modulator therapy in postmenopausal women at increased risk of breast cancer

The evidence regarding the risks, benefits, and quality of life impact of tamoxifen and raloxifene for prevention of breast cancer in postmenopausal women was reviewed. Five placebo-controlled trials were identified, four with tamoxifen and one with raloxifene. The individual placebo-controlled trials of tamoxifen for breast cancer prevention vary in size and risk status of the women who participated. An overview of the four trials found a 30% to 40% reduction in the risk of breast cancer. Serious adverse events include an increased risk of uterine cancer, venous thromboembolic events, and cataracts. Fracture risk was reduced. Quality of life was not significantly impaired, but women treated with tamoxifen had more vasomotor symptoms and vaginal discharge. In the single trial of raloxifene in postmenopausal women, there was a substantial reduction in the risks of breast cancer and fracture and no increased risk of uterine cancer. However, there was an increased risk of venous thromboembolic events. In the trial directly comparing tamoxifen with raloxifene in postmenopausal high-risk women, there was no significant difference in the risk of invasive breast cancer, but tamoxifen significantly reduced noninvasive breast cancer. The toxicity profiles for the two drugs were similar, with the exception of fewer hysterectomies, pulmonary emboli, and deep vein thrombosis in the raloxifene-treated group. There are now two effective Selective estrogen-receptor modulators available for use in postmenopausal women to reduce the risk of breast cancer. Women at high risk of breast cancer should be offered this therapy, and if one drug is not well tolerated, the other should be considered.

Breast Cancer Chemoprevention: A Review of Selective Estrogen Receptor Modulators

Breast cancer is the most common cancer diagnosis among women in the United States. Chemoprevention plays an important role for women at high risk for developing breast cancer. The use of selective estrogen receptor modulators (SERMs) tamoxifen and raloxifene has demonstrated mixed results in breast cancer prevention clinical trials. In the United States, tamoxifen is approved for use for breast cancer prevention in women at high risk. The continued development of SERMs with improved side-effect profiles is needed. Oncology nurses play a pivotal role in helping patients to understand the current status of breast cancer prevention as well as the future direction of research.

Percutaneous vertebroplasty and facet joint block

It is surprising that about 24% of patients with benign osteoporotic vertebral fracture die within a year from respiratory infection and urinary tract infection because of coughing and voiding difficulties, depending on the sites of compression fractures. We reviewed 500 patients on whom percutaneous vertebroplasty (PVP) was performed, at 612 levels in terms of patient selection, operation technique, medication, and clinical outcomes during the follow-up course for 2 yr study period. To confirm the most painful level among the multiple fracture sites, physical examination after facet joint block under the fluoroscope was the most reliable method. The mean total lumbar spine fracture threshold of bone mineral density was 0.81+/-0.05 g/cm2. The mean changes of numeric rating scale scores, Oswestry Disability Index except sex life, and Karnofsky performance status were -72.00, -83.50 and +60.62% in the osteoporosis group and -51.89, -45.02, and 69.03% in the tumor group. Complications related to the procedure were lateral spinal cord damage, transient paresthesia and transient hypotension. PVP with facet joint block is a profitable method for the vertebral compression fracture because of low risk and short duration of procedure with a high chance to result in pain relief and early mobilization.

Molecular mechanisms of breast cancer metastases to bone

Bone metastases lead to hypercalcemia, bone pain, fractures, and nerve compression. They cause increased morbidity and mortality in patients with advanced breast cancer. Animal models reproduce many of the features seen in patients with breast cancer and permit identification of tumor- and bone-derived factors important in skeletal metastasis. These factors provide novel targets for therapeutic interventions. Specific tumor-bone molecular interactions mediated by these factors drive a vicious cycle that perpetuates skeletal metastases. In breast cancer, osteolytic metastases are most common, but mixed and osteoblastic metastases occur in a significant number of patients. Parathyroid hormone-related protein is a common osteolytic factor, and vascular endothelial growth factor and interleukins 8 and 11 also contribute. Osteoblastic metastases can be caused by tumor-secreted endothelin-1 (ET-1), but there are a variety of other potential osteoblastic factors. Stimulation of osteoblasts can paradoxically increase osteoclast function, as bone-synthesizing osteoblasts are the main regulators of bone-destroying osteoclasts. Coexpression of osteolytic and osteoblastic factors can thus produce mixed metastases or increased osteolysis. Cancer treatments, especially sex steroid deprivation therapies, stimulate bone loss. Bone resorption results in the release of bone growth factors, which may unintentionally increase the formation of bone metastases by activating the vicious cycle. Clinically approved bisphosphonates prevent bone resorption and reduce the release of bone growth factors. Parathyroid hormone-related protein-neutralizing antibody, inhibitors of the receptor activator of nuclear factor-kB ligand pathway, and ET-1 receptor antagonists are in clinical trials. These agents act on bone cells rather than tumor cells. Recent experiments identify new potential targets for prevention of bone metastases.