Elderly and disabled women in the District are less likely to have routine mammography screening for breast cancer if they are African American or live in the city's less affluent wards, according to a report to be released today that encourages universal testing for women older than 50.

The report analyzes Medicare claims and shows that only 51 percent of black women ages 50 to 67 and living in the District had a mammogram in 2001 or 2002, compared with 61 percent of whites.

Ward 3, the city's wealthiest section, had the highest rate of women who had had a mammogram in that period, 66 percent, and was the only ward to do better than the 60 percent national average. The city's overall rate was 53.2 percent.

When the focus was narrowed, social and economic disparities grew. Zip code 20008, along the Connecticut Avenue NW corridor, had a rate of 71 percent, but Zip code 20002, including Capitol Hill and Lincoln Park, and 20019, encompassing Lincoln Heights, Marshall Heights and Benning Heights, each had a rate of 47 percent.

Medicare pays 80 percent of the cost of annual or semiannual mammograms for women older than 50. Breast X-rays to find cancers in healthy women cost Medicare an average of $94.77 in the District, and the women are responsible for average co-payments of $23.69, officials said.

The analysis was prepared by the Delmarva Foundation, a nonprofit group that advises Medicare about health services in the Washington region and other areas.

Deneen Richmond, the leader of Delmarva's District projects, called the report a reminder that too many women neglect a test that can give early warning of breast cancer at minimal expense.

The federal Centers for Disease Control and Prevention says that the five-year survival rate for localized breast cancer is 97 percent -- if doctors detect the disease early enough.

"The clear benefits of early detection are there," Richmond said. "Many women just aren't aware of the importance of having a mammogram on an annual basis. Women don't necessarily think about themselves or take care of their health."

Some neighborhoods have few or no health care providers offering mammograms, she said. Some women fear that the test is painful or that the mammogram can cause cancer, said Jennifer C. Stewart, clinical nurse manager with Project Wish, a D.C. Health Department program that provides free mammograms and Pap smears to low-income women.

Breast cancer, according to the CDC's Web site, is the second most commonly diagnosed cancer among American women, behind skin cancer. Only lung cancer takes more lives. In 2003, about 211,000 new cases of invasive breast cancer were diagnosed nationwide, and an estimated 39,800 women died of the disease.

The District's most recent breast cancer death rate was 42.6 deaths per 100,000 women, far higher than the national rate of 27 and the highest when compared with rates for states. City-to-city comparisons are not available, according to a CDC spokeswoman.

Delmarva surveyed claims data on all 5,319 District female residents ages 50 to 67 who were enrolled in Medicare during those two years. Medicare covers everyone older than 65 and people with a variety of serious disabilities.

Jeanne Mandelblatt, director of the cancer prevention program at Georgetown University's Lombardi Comprehensive Cancer Center, said the report highlights a major public health problem. "Older women are at the highest risk of developing breast cancer because increasing age is the single greatest risk factor," she said.

Cancer experts have reached a consensus that mammograms are valuable for women older than 50, but a controversy has not been settled over whether mammograms save lives of women younger than 50.

Some women's lives are saved by mammography, but many detected cancers might never have killed the patient if undiscovered, some specialists say. Some cancers kill despite early warning, and others are curable even if detected later, they say.

Federal officials tried to settle the debate in 2002 with a recommendation that women older than 40 be screened at least every other year. So far, screening rates have been too low to satisfy federal officials. The Delmarva report was done as part of a mammography campaign launched at the request of Medicare officials.

According to federal data, screening rates for the period of 2000 and 2001 among female Medicare enrollees ages 50 to 67 were 57 percent in Baltimore, 61.6 percent in Montgomery County, 52.8 percent in Prince George's County, 56.1 percent in Alexandria, 55.1 percent in Arlington, 58.9 percent in Fairfax County and 50.8 percent in Prince William County.

Screening rates for the same period in New York City were 51.1 percent; Fulton County, Ga., including Atlanta, 56.1 percent; and Philadelphia, 52.4 percent.

Mandelblatt, who heads a new mammography clinic on Capitol Hill that can screen 20 women a day, said cultural barriers are crucial. "Many populations hold fatalistic attitudes," she said. "Women of African American descent have often not been treated as well. Many have difficulties trusting the institutions providing health care."