Preventative measures for lymphedema: separating fact from fiction.

Lymphedema is the accumulation of protein-rich fluid that occurs when the ability of the lymphatic system to transport interstitial fluid is exceeded. This devastating disorder affects an estimated 3 to 5 million Americans and a staggering 140 to 200 million people worldwide. In the United States and Western countries, lymphedema occurs most commonly as a complication of lymph node dissection for cancer treatment. It is estimated that as many as 30% to 50% of patients who undergo lymph node dissection go on to develop lymphedema. Lymphedema can occur even after less invasive procedures such as sentinel lymph node dissection, thereby putting nearly all cancer survivors at risk for this dreaded complication. Although lymphedema occurs most commonly as a complication of breast cancer management, it is also seen frequently in patients treated for other solid malignancies. In fact, a recent meta-analysis of nearly 8,000 patients reported an overall incidence of 16% in patients treated for melanoma, sarcoma, and gynecologic, urologic, and head and neck malignancies. Patients with lymphedema have chronic, progressive swelling, pain, recurrent infections, and significantly decreased quality of life. The swelling can progress to gigantic proportions, causing gross disfigurement with severe detrimental effects. In addition, lymphedema is a significant source of biomedical expenditures, with one recent study demonstrating a more than $10,000 increase in the annual treatment costs of cancer survivors with lymphedema as compared with those without lymphedema. Treatment for lymphedema remains suboptimal and is in most cases palliative, with a goal of preventing disease progression rather than a cure. Medical and surgical treatments have been reported, but in general these therapies have been disappointing and the results are sometimes difficult to reproduce. In most instances, patients are treated with life-long physical therapy with manual lymphatic drainage and require tight-fitting, uncomfortable elastic garments. Due to the expense, time, and discomfort associated with these treatments, there is a high degree of noncompliance and associated disease progression. Despite the morbidity and costs of lymphedema, the mechanisms that regulate its development remain largely unknown. It remains unclear, for instance, why some patients develop lymphedema and others who are identically treated do not. Similarly, it is unknown why certain risk factors such as radiation, obesity, or infection increase the risk of lymphedema. Perhaps the most perplexing aspect of lymphedema is the fact that it develops in a delayed manner, usually 1 to 5 years after surgery. Sometimes lymphedema can develop even decades after surgery after seemingly trivial trauma. This gap in our knowledge has prevented development of targeted treatment options. Similarly, our lack of understanding of the cellular and molecular mechanisms in development of lymphedema have complicated effective preventative strategies. In fact, many of the current recommendations for prevention of lymphedema are anecdotal with scant scientific evidence. The National Cancer Institutes PDQ information summary about preventative steps for lymphedema states the risks succinctly as those of the current recommendation from The Royal Marsden Hospital (UK), and The National Lymphedema Network presented in Table 1. However, the National Lymphedema Network states that there is little evidence-based literature with respect to many of these recommendations and the majority of them are based on what is known through decades of clinical experience and comprehension of the pathophysiology by experts in lymphedema. The purpose of this systematic review was to evaluate the current recommendations for prevention of lymphedema and present current scientific evidence supporting or disputing these claims.