DFL is generally an indolent disease which progresses to a more aggressive form in <10% of cases. A watch-and-wait strategy has been a generally recommended treatment for the disease in the United States, Japan, and Europe. However, numerous approaches have been used to treat the disease. Patients with disease that is contained within a limited radiation field have been treated with radiation therapy to attain overall 10 year survival rates of 60-80%. However, one study found that radiation-treated patients had a relapse rate of 48%. A retrospective analysis conducted on a small number (i.e. 63) of patients found complete regression rates for a watch-and-wait tactic, radiotherapy, and rituximab (a monoclonal antibody directed against CD20) of 29%, 100%, 80%, respectively. The complete regression rate for a CHOP chemotherapy regimen, CHOP plus rituximab regimen, radiotherapy plus rituximab regimen, pancreaticoduodenectomy (i.e. surgical removal of the duodenum and pancreas), and other chemotherapeutic regimens, when combined as a single group, was 64%. Only two patients in this study had diseases which progressed to outside of the GI tract; both were in the watch-and-wait group. Until further studies are conducted to define the optimal regimens for treating DFL, most patients with the disease are being initially treated with a watch-and-wait approach in order to avoid the toxic side-effects of the cited alternate regimens.
