The world's largest database of cancer patients is being set up in England in an attempt to revolutionise care, Public Health England has announced. It will collate all the available data on each of the 350,000 new tumors detected in the country each year. The aim is to use the register to help usher in an era of "personalized medicine" that will see treatments matched to the exact type of cancer a patient has. Experts said it was "great news". The old definitions of cancer - breast, prostate, lung - are crumbling. Cancer starts with a mutation that turns a normal cell into one that divides uncontrollably and becomes a tumour. However, huge numbers of mutations can result in cancer and different mutations need different treatments. Research into the genetics of breast cancer means it is now thought of as at least 10 completely separate diseases, each with a different life expectancy and needing a different treatment. The national register will use data from patients at every acute NHS trust as well 11 million historical records. It will eventually track how each sub-type of cancer responds to treatment, which will inform treatment for future patients.