Biologic, Socioeconomic Factors Appear Significant
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B-cell non-Hodgkin lymphoma
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Resistant non-Hodgkin lymphoma (NHL) is the leading hematologic cancer in adults, with more than 65,000 US cases expected annually. Approximately 85% of these lymphomas are of
B-cell origin: some slow-growing and incurable; others aggressive yet often curable.
Recent UAB studies are the first to show racial and socioeconomic disparities in lymphoma. "Despite well-established clinical prognostic indices, significant heterogeneity in survival remains, even within prognostic groups," says hematologist-oncologist James M. Foran, MD. Black patients are less likely than whites to develop lymphoma, he says, but when diagnosed, they have a significantly worse survival rate despite receiving similar treatment.
Initially surprised when black patients in his practice survived less often than expected, Foran developed a database of UAB patients (1995 to the present) and, with epidemiologists from UAB's School of Public Health, confirmed that blacks have a significantly lower incidence of NHL than whites but do not respond as well to treatment. "We confirmed that independent of treatment, black patients had worse 1-year and overall survival, were less likely to receive the monoclonal antibody rituximab—the standard of care—and were less likely to be treated within 30, 60, and 90 days of diagnosis, despite having similar access to care."
In a separate analysis with the large multiethnic California Cancer Registry, UAB researchers found that lower socioeconomic status (SES) also is an independent risk factor for reduced survival. "We found SES trumps race in determining survival," he says. NHL patients living under the poverty level experienced decreased survival compared with those of high SES despite early treatment with rituximab. Investigators presented findings at recent scientific meetings of the American Society of Hematology and the International Conference on Malignant Lymphoma.
Foran's team is gathering tissue from patient biopsies for examination of biologic factors. To investigate sociologic issues, he is designing a prospective case-control study expected to begin enrolling partici-pants in 2009. "A parallel UAB study will investigate whether racial differences in immune response predict a higher incidence of the late B-cell malignancy of myeloma instead of the earlier B-cell malignancy of lymphoma."
Patient education to maximize compliance with treatment and follow-up are crucial, he says. "We believe SES does not predict the choice of the initial therapy but does predict survival. In addition, compelling evidence confirms that patients with aggressive NHL should be treated in the first 30 days after diagnosis," Foran says.
Racial disparity associated with NHL survival is a relatively new discovery, he says.
"The international consortium InterLymph is studying the causes of lymphoma, but unfortunately, of the more than 10,000 patients enrolled in its studies, only 200 are black," he says. "UAB and our referring physicians are uniquely positioned to conduct epidemiological studies that may play leading roles in defining and confronting the issues in lymphoma."
For more information contact Dr. James Foran at 1-800-UAB-MIST or at mist@uabmc.edu