A detailed new study of cancer death rates in the District of Columbia shows that poverty may play as great a part as race in affecting cancer mortality.

While researchers have known for some time that black males in Washington have the highest cancer mortality rates in the nation, the new study appears in show as much difference between the mortality rates of poor and middle-class blacks as between middle-class blacks and middle-class whites.

The study, conducted by researchers at the Howard University-Georgetown University Comprehensive Cancer Center, has uncovered striking differences in the cancer death rates in various areas of the city.

According to the study, about one-third more men die of cancer in the 89 percent black, predominantly middle class, far northeast section of the city than in the 95 percent white area west of Rock Creek Park.

One-third more men die of cancer in the 91 percent black heart of inner Northwest - which has the city's greatest poverty - than in the black, middle class area of Northeast, according to the study.

It also found that those areas with the highest cancer death rates also have the highest death rates from heart disease, stroke and cirrhosis of the liver. All death rates were adjusted to account for age variations in the population.

Because most cancers take at least 20 years to develop, and the District is such a small geographic area, researchers Dorothy Parker and John P. Enterline do not believe the different rates in different areas have anything to do with the areas themselves.

Rather, they say, the strikingly different rates may spring from such population variables as race, income level, general state of health, diet, and, perhaps, the areas lived in before coming to Washington.

According to the study, service area eight, that portion of the city west of Rock Creek Park - which has the highest median family income and the highest number of whites, has the lowest overall cancer death rate.

Service area six, which includes the heart of the inner Northwest and has the city's lowest median family income, a high proportion of blacks and the highest percentage of families below the poverty line - has the highest combined male and female cancer death rate.

Both the study and Dr. Jack White, director of Howard's half of the joint Howard-Georgetown center, point out that Washington has a high proportion of black residents who migrated from the rural south, which has extremely high cancer rates.

One of the things the researchers want to look at now, said Enterline, is the place of birth of cancer victims in the District.

According to White, it is possible that persons from particular cancerprone areas of the South have tended to settle in particular service areas in the District - such as inner Northwest - raising that area's cancer death rates.

The study "provides government agencies with meaningful data they can begin including in their planning," said White, who, along with Parker, said the city should begin placing health resources in those areas with the highest cancer rates.

"The priorties of people that you have in the (poor areas) vary greatly from the priorities of people in another economic area," said White. "They want to feed and clothe their families. They don't want to dress up and go across town" for health care.

The poor, he said, are so wrapped up in the daily struggle for survival that they often wait until it is too late to go to a physician or hospital with a physical complaint. This hesitency to seek early treatment may be one of the factors accounting for the difference in death rates between poor and middle class residents, he said.

Another factor which may affect survival, said White, is the overall ill health of the poor. Many anti-cancer treatments, such as radiation and chemotherapy, exact a toll of their own. If a person isn't in good shape to begin with, said White, the therapy, combined with the cancer, may prove too great a strain on the individual's system.

"Poor health," said Enterline, "leads to poorer health."

According to Parker, the principal author of the study, there may be one major flaw in the data, and that concerns service area four, that area of southest Washington east of the Anacostia River and south of Pennsylavnia Avenue.

Although that area is 86 percent black and has the third lowest median family income in the city, it has the second lowest male cancer death rate in Washington.