Rowan T. Chlebowski, MD, PhD

The review by Jennifer Ligibel, MD, approaches a topic of increasing importance-namely the role of obesity in breast cancer incidence and clinical outcome-in a comprehensive and up-to-date fashion, focusing on obesity and its influence on breast cancer recurrence and associated survival.

Over 40 million men and women in the United States have osteoporosis and low bone mineral density (BMD), placing them at risk for adverse skeletal events such as fractures and their sequelae. There are over 12 million cancer survivors in this country. Of these, 22% were diagnosed with breast cancer and 17% with prostate cancer.[1,2] Because cancer therapies can adversely influence bone health, these survivors are at particular risk for skeletal complications. Cancer therapies associated with bone loss include hormone deprivation therapies such as aromatase inhibitors, ablative surgical procedures that induce hypogonadal states, and premature menopause induced by chemotherapy.[3,4]

The 2005 National Health Disparities Report found disparities related to race, ethnicity, and socioeconomic status in the United States health-care system. While varying in magnitude, disparities were observed in almost all aspects of health care including cancer. Disparities were noted across quality and access to health care, levels and types of health care, various health-care settings, and within many subpopulations. In this review, we explore the disparities in cancer care among racial and ethnic minorities. In particular we consider numerous factors that may influence health care for racial and ethnic minority groups including socioeconomic issues, access, cultural beliefs, risk factors, and comorbidities. Although there are extensive confounding factors that vary with each subgroup, trends that may help individual practitioners better understand this complex issue become evident through closer evaluation of available data.

The aromatase inhibitors (AIs) anastrozole (Arimidex), letrozole (Femara), and exemestane (Aromasin) are significantly more effective than the selective estrogen-receptor modulator (SERM) tamoxifen in preventing recurrence in estrogen receptor-positive early breast cancer. Aromatase inhibitors are likely to replace SERMs as first-line adjuvant therapy for many patients. However, AIs are associated with significantly more osteoporotic fractures and greater bone mineral loss. As antiresorptive agents, oral and intravenous bisphosphonates such as alendronate (Fosamax), risedronate (Actonel), ibandronate (Boniva), pamidronate (Aredia), and zoledronic acid (Zometa) have efficacy in preventing postmenopausal osteoporosis, cancer treatment-related bone loss, or skeletal complications of metastatic disease. Clinical practice guidelines recommend baseline and annual follow-up bone density monitoring for all patients initiating AI therapy. Bisphosphonate therapy should be prescribed for patients with osteoporosis (T score < -2.5) and considered on an individual basis for those with osteopenia (T score < -1). Modifiable lifestyle behaviors including adequate calcium and vitamin D intake, weight-bearing exercise, and smoking cessation should be addressed. Adverse events associated with bisphosphonates include gastrointestinal toxicity, renal toxicity, and osteonecrosis of the jaw. These safety concerns should be balanced with the potential of bisphosphonates to minimize or prevent the debilitating effects of AI-associated bone loss in patients with early, hormone receptor-positive breast cancer.

Anne McTiernan has provideda comprehensive and balancedreview of a complex topic,namely, “Obesity and Cancer: TheRisks, Science, and Potential ManagementStrategies.” The impressiveweight of assembled evidence from thecited observational studies has been sufficientto influence several cancer organizations,including the AmericanCancer Society and the American Institutefor Cancer Prevention, to issuerecommendations regarding nutritionand physical activity in relationship tocancer.[1,2] However, clinical practiceis unlikely to undergo substantialchange in the absence of prospectivetrials demonstrating benefit on clinicaloutcomes.[3] For at least the breast cancerand obesity question, informationfrom phase III randomized, prospectiveclinical trials evaluating lifestyleintervention influence on clinical outcomeare anticipated in the near future.

The "Update on Breast CancerPrevention" by Rastogi andVogel provides a comprehensiveand balanced review of the currentstatus of breast cancer chemoprevention.Several areas that the authorsaddress warrant further attention.