Poverty Link to Brain Cancer Found
Differences most pronounced in younger persons, Michigan study says
TUESDAY, May 25, 2004 (HealthDayNews) -- Poverty boosts your risk of brain cancer, new research contends.
Michigan State University researchers compared the rate of brain cancer among Medicaid enrollees to all others who developed brain cancer in the state of Michigan during 1996 and 1997.
The overall rate of cancer of the brain was 8.1 per 100,000 in the 1,006 cases they studied. But among those with low incomes, the rate was 14.2 cases per 100,000, nearly double the 7.5 cases per 100,000 for all others. The findings appear in the May 25 issue of Neurology.
"We've identified this group of people with very low incomes as being very prone or susceptible to developing brain cancer," said lead researcher Paula R. Sherwood, a doctoral candidate at Michigan State University in East Lansing.
"We really don't know what causes brain tumors," Sherwood said. However, the low income association may eventually lead to more clues, she added.
While it is possible the results spring from the fact that people with brain tumors are eligible for Medicaid (the U.S. government program providing medical assistance for those with very low income) because the tumor is a disability, the researchers feel there are other reasons for the results.
Sherwood said the short survival time for brain cancer, combined with the Medicaid requirement that you spend down your assets and be disabled for at least 12 months may have made it difficult for a middle-class person to have become eligible for Medicaid during the research project's two-year study period. When the researchers analyzed only those who were eligible for Medicaid before their diagnosis, the pattern supported the study findings.
Exactly why low income is associated with higher rates of brain cancer isn't known. Low-income persons "have more environmental exposures to environmental toxins," Sherwood said. And, she added, those with lower incomes may have less access to health care or may have a level of education that could limit their knowledge of how to access treatment.
The associations were strongest in younger people, she found. Men under age 44 who had low incomes were at least four times as likely to develop brain cancer as those not having low income. Women under age 44 with low incomes were 2.6 times more likely to get brain cancer than those who didn't have low incomes.
For the 1997 year, according to the study, enrollment in Medicaid had a poverty threshold of $8,183 for a single-person household and $10,473 for a two-person household.
Another expert questioned whether the income level was the key factor that makes a difference.
"It is an interesting association, but my guess is the income is a surrogate for something else," said Dr. Lauren Abrey, an assistant attending neurologist at Memorial Sloan-Kettering Cancer Center in New York City.
"One thing that is associated [with brain tumors] is working with the petroleum industry," she added, questioning whether most Medicaid patients live in Detroit, which has a lot of factories.
Or, she noted, the income level may trigger stress.
"Are these people's lives so stressful that they are set up to develop brain tumors?" she asked.
About 18,400 malignant tumors of the brain or spinal cord are expected to be diagnosed this year in the United States, according to the American Cancer Society.