Lymphedema develops when the lymphatic system is unable to carry large proteins and lymph fluid away from a region of the body. This condition can occur either from primary causes such as congenital malformations of the lymphatic system as it develops, or secondary causes such as trauma/injury, infection, surgery, radiation or inflammation. It is characterized by gross swelling of the affected limb, significant pain and discomfort, accompanied by fibrosis, susceptibility to serious infections (cellulitis and skin ulcers) and can lead to severe deformity (elephantiasis) and even amputation.

 

Secondary lymphedema in Western countries most commonly occurs as a result of cancer treatment. Metastatic tumor cells (particularly breast cancer and melanoma) can frequently spread via the lymphatic vascular system and colonize in lymph nodes, necessitating radical surgery that often destroys lymphatic vessel networks and leads to impairment of afferent lymphatic flow. Many of these patients undergo irradiation therapy as part of this treatment, which can further worsen the condition.It’s estimated that 4-6 million patients in the US and EU suffer from secondary lymphedema.

 

Breast cancer-associated lymphedema is the most common form of Secondary Lymphedema, with an estimated 300,000 new cases per year occurring in western countries.  A 2011 study showed that about five percent of breast cancer survivors who had sentinel node biopsy and about 35 percent of women who had axillary lymph node dissection developed lymphedema (Susan G. Komen).

 

Lymphatic filariasis, a parasitic insect-transmitted infection that is prevalent in tropical regions, is the most common cause of secondary lymphedema internationally. The World Health Organization estimated the global burden of filariasis to be 120 million cases, with 1 billion people being at risk of infection.