Black women are about 40% more likely to die of breast cancer than White women, but new research is showing this applies to all forms of the disease — and examines why. 

In the study, published in the Journal of Clinical Oncology Tuesday, researchers found black women are at higher risk of dying from all tumor subtypes of breast cancer, with the size of this disparity varying from 17% to 50% depending on the type of breast cancer.

The research used data from 18 studies that were published between 2009 and 2022, analyzing a total of 228,885 breast cancer cases, 34,262 of which were in Black women.

“These findings underscore a stark reality in our healthcare system: Black women are facing higher risks of death from breast cancer compared to their white counterparts, across all types of the disease. This disparity isn’t just about biology,” co-author Paulette Chandler, associate epidemiologist in the Division of Preventive Medicine at Brigham and Women’s Hospital, said in a news release. 

Authors found the contributing factors include socioeconomic inequality, delays in diagnosis and inadequate access to timely quality cancer treatment.

“To achieve equity, intervention is necessary at multiple levels — from community to healthcare systems and individual healthcare providers, to patients themselves learning about their disease and what their expectations should be for their care,” senior author Erica Warner, a cancer epidemiologist at Massachusetts General Hospital, said in the release.