Cancer isnt just a modern-day affliction. A new archaeological analysis suggests malignant growths in medieval Britain were not as rare as we once thought. Even before widespread smoking, the Industrial Revolution, and the modern surge in life expectancy, it seems cancer was still a leading cause of disease. Scanning and X-raying 143 medieval skeletons from six cemeteries in and around the city of Cambridge, archaeologists have predicted cancer cases between the 6th and the 16th century were roughly a quarter of what they are today. Thats 10 times higher than previous estimates, which had put cancer rates at less than one percent. "Until now it was thought that the most significant causes of ill health in medieval people were infectious diseases such as dysentery and bubonic plague, along with malnutrition and injuries due to accidents or warfare. We now have to add cancer as one of the major classes of disease that afflicted medieval people," archaeologist Jenna Dittmar from Cambridge University said in a report published by the Science Alert website. Past analyses of medieval skeletons in Britain have only focused on the exterior of the bone, but Dittmar and her colleagues decided to look for evidence of metastases within the bone, too. Scanning parts of the skeleton that are more likely to hold cancerous growths, such as the spinal column, the pelvis, and the thigh bone, the team found signs of malignancy in five individuals from medieval times. Most cases were confined to the pelvis, but there was one middle-aged man that had lesions scattered throughout his skeleton, which is indicative of blood cancer. "Using CT scans we were able to see cancer lesions hidden inside a bone that looked completely normal on the outside," says Dittmar. Based on these statistics, the authors think the minimum prevalence of all cancers in medieval Britain would have sat somewhere between 9 and 14 percent. The sample size of the current study was obviously small and focused on only one region. Yet even with these caveats in mind, the findings suggest we have been missing many cases of medieval cancer by not looking within the bone. "We need further studies using CT scanning of apparently normal skeletons in different regions and time periods to see how common cancer was in key civilizations of the past," said author of the new research, archaeologist Piers Mitchell from Cambridge University.