A urine test for breast cancer could replace mammograms, researchers say.

Currently, mammography or ultrasound is used to make a breast cancer diagnosis, which is then confirmed with tissue biopsy.

These methods expose women to dangerous radiation, invasive intervention, and are subject to erroneous results. However, German researchers say they have developed an experimental breast cancer test that uses a urine sample. It is capable of detecting tumors on the basis of changes in metabolism, they say.

Breast cancer produces characteristic changes in short genetic sequences called microRNAs which enter the urine from the blood.

The new urine test was found to be 91 percent accurate, finding even early-stage breast cancers.

If the test’s effectiveness is confirmed in further studies, it could supplement or even replace standard mammograms, the researchers said.

About one in eight women will develop invasive breast cancer in their lifetime, making it the most common type of tumor in women, statistics say.