Study of Lymphatic Dysfunction in Primary and Secondary Lymphedema

Primary lymphedema is an inherited condition whereas secondary lymphedema develops after cancer treatments. Despite common phenotype, a molecular and histological comparison of these two pathologies has never been performed. Primary lymphedema is associated with heterozygous inactivating mutations of the gene encoding vascular endothelial growth factor C and D receptor (VEGFR-3). Primary lymphedema is rare, affecting 1 in 100,000 individuals. Secondary lymphedema is the most common cause of the disease and affects more than 200 million people worldwide. Secondary lymphedema occurs months, sometimes years after cancer surgery suggesting that lymphedema is not only a side effect of the surgery, but involves modifications of the lymphatic architecture as well as its microenvironment, in particular adipose tissue that accumulates in the limb. There is no cure for lymphedema because of the lack of identified therapeutic strategies able to restore collecting lymphatic draining function in the arm or in the leg. The goal will be to establish if these pathologies which possess a common denomination exhibit a similar gene expression.