On Monday, UCLA researchers released a new study that found wealthy women had better access to a new type of test that more effectively determines the proper treatment for early-stage breast cancer.

That jibes with a study from Yale University researchers, also released on Monday, which said higher costs of breast cancer care have been accompanied by improvements in survival.

According to Ninez Ponce, associate director of the UCLA Center for Health Policy Research and lead author of the UCLA study, ability to access effective early breast cancer care was strongly linked to income disparities.

“Even among women who have insurance, where they live and how income is distributed in their community were closely linked to their chance of getting access to an effective innovation in the early years of its diffusion,” Ponce said.

The new test, called gene expression profiling, estimates a patient’s risk of having a recurrence of a disease, Ponce said. If a woman has early-stage, estrogen-receptor–positive, lymph-node–negative breast cancer with a low-risk test score from gene expression profiling, she may not benefit as much from chemotherapy — however, a woman with a high-risk gene expression profiling test score should consider chemotherapy.

The study found that the greater the income-disparity gap, the greater the gap in testing with gene expression profiling. In communities with less income disparity, take-up of the new type of testing was slower than in the communities with wide income gaps.

Both the UCLA and Yale studies were published on Monday in Health Affairs.

According to Cary Gross, director of Cancer Outcomes Public Policy and Effectiveness Research Center at Yale School of Medicine, better outcomes were primarily linked to more-expensive treatments.

“In some instances, newer and costlier approaches may be leading to improved outcomes in breast cancer patients,” Gross said in an interview with the Science 2.0 site. “The cost increase was largely attributable to a substantial increase in the cost of chemotherapy and radiation therapy.”