After screening the blood samples to see if they could detect auto-antibodies triggered by tumour antigens, the researchers correctly identified breast cancer in 37% of blood samples taken from affected patients.
According to the researchers, the test could save thousands of lives as the disease is far easier to treat if detected early, and may relace the mammogram as a screening method.
"We were able to detect cancer with reasonable accuracy by identifying these autoantibodies in the blood," says Daniyah Alfattani, a PhD student in the research group.
"These results are encouraging and indicate that it's possible to detect a signal for early breast cancer."
They estimate that, with a fully-funded development programme, the test might become available in the clinic in about four-to-five years.
Dr Kotryna Temcinaite, of Breast Cancer Now, hailed the "exciting" study.
"Finding ways to detect breast cancer earlier will be crucial if we're to stop more women dying from the disease."