Non-Hodgkin lymphoma is a cancer of the lymphatic system and usually starts in lymphocytes (white blood cells) found in one or more lymph nodes. White blood cells are a part of the lymphatic system that helps fight diseases and infections. There are many types of non-Hodgkin lymphoma. The type is determined by how the cancerous cell looks under a microscope.
Non-Hodgkin lymphoma can occur at any age, but the incidence increases with age, especially after the age of 60. Non-Hodgkin lymphoma makes up approximately 4% of new cancer cases each year, and there is a 1 in 42 lifetime chance for Canadian men, and a 1 in 54 lifetime chance for Canadian women, of having this type of cancer.