New Scientist -- Thousands of women could be spared surgery for breast cancer with a test that can predict the likelihood of developing an invasive tumour. Thea Tlsty and colleagues at the University of California, San Francisco, analysed breast tissue from 70 women who had been diagnosed with a breast-cancer precursor called ductal carcinoma in situ. They looked for abnormal expression of the proteins p16 and ki67, which are linked to tumour growth and cell proliferation, and also for the enzyme Cox-2.