American women with HIV are 76% more likely to be diagnosed with breast cancer late and nearly two and a half times more likely to die from it than their HIV-negative sisters. That’s higher than rates found among women in sub-Saharan Africa.

The findings don’t take into account the stage of HIV progression, though, so it’s unclear whether the results are the same for women on different antiretroviral treatment or for those with an undetectable viral load, or whether a history of AIDS plays a role. The analysis also didn’t break down the results by health care access, and none of the studies addressed implicit bias against women of color.

The findings come from a systematic review and meta-analysis of 18 studies that together included 3,174 HIV-positive women and 2.3 million HIV-negative women with breast cancer.

Four of those studies were conducted in the United States, comprising 1,638 women with HIV who were later diagnosed with cancer. None of the U.S. studies included data on the women’s CD4 counts, and the study authors did not report data on how many women were on antiretrovirals. In these studies, the proportion of HIV-positive participants who were Black ranged from 45% to 91%. That differed from the HIV-negative women who developed breast cancer, who were generally less likely to be Black.

Mariana Brandão, MD, PhD, of Université Libre de Bruxelles, and colleagues pooled the findings from these four studies and compared them with the results of the other 14 studies, largely conducted in sub-Saharan Africa. They discovered that women with HIV had an increased risk for late diagnosis—that is, diagnosis of breast cancer when it’s already spread, either locally or throughout the body—rather than at earlier, more treatable stages. This disparity was even more pronounced in the United States.

In sub-Saharan Africa, women with HIV were 23% more likely to be diagnosed with late-stage breast cancer than their HIV-negative peers. But in the United States, women with HIV were 76% more likely to be diagnosed at late stages. U.S. women with HIV were also more likely to develop estrogen-receptor-positive/HER2-negative breast cancer.

When it came to survival, the results were even more grim: HIV-positive women with breast cancer in the United States were 245% less likely to survive after a breast cancer diagnosis than their HIV-negative peers. This is perhaps due to the especially high mortality odds ratio in one study (462%). When researchers excluded that study, the results were more modest and consistent across studies—a 77% increased risk of dying from breast cancer versus a 245% increased risk of dying.

Still, even the lower rate in the US was higher than that of HIV-positive women with breast cancer in sub-Saharan Africa, whose increased mortality rate was 58%. These odds were adjusted for demographic data, such as age, race, breast cancer subtype and income but not for other health conditions. Tellingly, the meta-analysis authors didn’t adjust for stage of HIV progression.

“This is a limitation, as low CD4 count at cancer diagnosis seems to be associated with worse survival among patients with non-AIDS-defining malignancies and could be a potential factor to explain why survival outcomes are worse among some women living with HIV with breast cancer,” the study authors wrote. Still, the findings could guide practice and research.

“For [women living with HIV] who already have developed breast cancer, an effort should be made to provide a similar [level of] care to the one given HIV-negative patients, namely in terms of access to effective treatment and adequate follow-up,” they wrote. “These patients should also be included in clinical trials of new anticancer therapies.”

Click here to read the study abstract.

Click here to learn more about breast cancer.