Nearly a quarter of African American women with advanced breast cancer decline to be treated with chemotherapy or radiation.

Researchers looked at over 100 cases of advanced breast cancer over a 6-year period. A majority of the patients were African American.

Doctors usually recommend chemo and radiation for these patients -- treatments they say can be life-saving.

But for reasons that are still unclear -- 20% of African American women opted out of chemo and 26% said no to radiation.

Black women have nearly twice the rate of advanced breast cancer than white women.