The test is being developed at Llanelli's Prince Phillip Hospital with the help of Singleton Oncology and the University of Swansea.
During recent trials, nearly half of patients who were initially recommended for chemotherapy and endocrine therapy, had their treatment changed to endocrine therapy alone.
This test will have a major impact on the lives of many women, allowing them to get on with their lives following breast cancer surgery rather than having to go through four months of chemotherapy."
The 'Oncotype DX' test, which is only for women with early breast cancer, will give clinicians a clearer idea of the risk and benefit of chemotherapy.
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The owners of what some people claim to be the 'Welsh Holy Grail' are offering a cash reward for the ancient artefact's safe return.
Staying mostly dry overnight with generally light winds, but cloud and wind will gradually increase from the northwest from the early hours.
In the last programme we've been to meet two Welsh entrepreneurs who chose a different route and we visit the Energy Centre at Coleg Menai.