July 18 (HealthDay News) -- The prevalence of mantle cell lymphoma, an aggressive form of non-Hodgkin lymphoma, is increasing, and most patients are diagnosed with advanced stages of the disease, notes a study by researchers at the University of Texas M.D. Anderson Cancer Center.

Mantle cell lymphoma is a fast-growing, incurable cancer of the immune system, characterized by cancer cells that may be in the lymph nodes, spleen, bone marrow, blood or gastrointestinal system.

The study authors found that the incidence of mantle cell lymphoma increased from 2.7 people per one million in 1992 to 6.9 per one million in 2004. The cause of this increase is unknown.

An examination of the records of 2,459 people diagnosed with mantle cell lymphoma between 1992 and 2004 showed that men were more than twice as likely as women to be diagnosed with the disease, and that Caucasians had the highest risk of all ethnic groups.

Age was also a factor. People ages 70 to 79 were more likely to be diagnosed with the disease than all other age groups. The researchers also found that almost three-quarters of all mantle cell lymphoma patients were diagnosed with advanced disease (stages III and IV).

Because the disease often goes undetected until later stages, it has the poorest prognosis of all lymphomas. New anti-cancer therapies have helped improve survival rates of various types of non-Hodgkin lymphoma, but there is no clear standard approach for treating mantle cell lymphoma, the researchers said.

"A better understanding of the epidemiology of mantle cell lymphoma, the development of novel agents, more research funding and increased public awareness are all needed," they wrote.

The study is published in the Aug. 15 issue of the journal Cancer.

SOURCE: Cancer, news release, July 7, 2008