THURSDAY, Feb. 5 (HealthDay News) -- Most breast cancers in Hispanic women are detected by the women themselves, despite high rates of screening mammography in this population, a new study shows.

What's troubling, however, is that about half of all women who noticed an abnormality waited at least a month before seeking medical help, according to new research being presented at the American Association for Cancer Research Conference on the Science of Cancer Health Disparities, in Carefree, Ariz.

Two-thirds of breast cancers in Hispanic women are discovered by accident, while only 23 percent come to light through a mammography and another 6 percent through a clinical exam. Yet screening mammography rates were 83 percent among U.S.-born Hispanic women and 62 percent among non-U.S.-born Hispanic women, said researchers from The University of Arizona Mel and Enid Zuckerman College of Public Health.

Why did women wait so long before seeking help? Largely because of lack of health insurance or other ways to afford medical care, study author Rachel Zenuk said during a Wednesday teleconference on the findings.

The study is one of several being presented at the conference that look at breast cancer issues among Hispanic women.

According to Elena Martinez, a professor of epidemiology at The University of Arizona Mel and Enid Zuckerman College of Public Health and co-leader of the Cancer Prevention and Control Program at the Arizona Cancer Center in Tucson, "the problem [of breast cancer] is very poorly understood in this population, and it's an issue that affects the U.S. because of the large and growing population of Hispanics in this country."

Two of these studies, including the one noted above, rely on data from the ELLA Binational Breast Cancer Study which, so far, has recruited 652 women, about half Mexican-American women in the United States and half in Mexico. The study has so far determined that women in Mexico tend to be diagnosed at an older age than women in the United States, although many risk factors were similar.

The second study to use ELLA data found that Hispanic women with a family history of breast cancer were more likely to have triple-negative breast cancer, although the same did not hold true of black women with a family history of the disease. This means the tumor is estrogen-receptor-negative, progesterone-receptor-negative, and HER2neu-receptor-negative and would call for different treatment options than other breast cancer types.

But the increased risk among Hispanic women was only seen in those born in Mexico, not among those born in the United States.