Cancer rates in medieval Britain were around 10 times higher than previously thought, a study of skeletons has suggested.
Past studies had indicated that the disease affected less than 1% of the population in an age before cigarettes and polluting chemicals from industry, and with shorter life expectancies giving cancer less time to develop.
However, a Cambridge University study which used x-rays and CT scans for the first time has suggested that between nine and 14% of the population died with cancer.
Researchers examined the remains of 143 skeletons from six medieval cemeteries in and around Cambridge, dating from the sixth to the 16th century.
Previous studies were limited to examining the bone exterior for lesions, but the most recent study also deployed radiological imaging.
Lead author Dr Piers Mitchell, of Cambridge’s Department of Archaeology, said: “The majority of cancers form in soft tissue organs long since degraded in medieval remains.
“Only some cancer spreads to bone, and of these only a few are visible on its surface, so we searched within the bone for signs of malignancy.
“Modern research shows a third to a half of people with soft tissue cancers will find the tumour spreads to their bones.
“We combined this data with evidence of bone metastasis from our study to estimate cancer rates for medieval Britain.
“We think the total proportion of the medieval population that probably suffered with a cancer somewhere in their body was between nine and 14%.”
Dr Jenna Dittmar, study co-author and a researcher on the After the Plague project, said CT scans allowed the team to see cancer lesions “hidden inside a bone that looked completely normal on the outside”.
“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,” she said.
“We now have to add cancer as one of the major classes of disease that afflicted medieval people.”
Researchers point out that in modern Britain some 40 to 50% of people have cancer by the time they die, making the disease three to four times more common today than the latest study suggests it was during medieval times.
They say that a variety of factors likely contribute to contemporary rates of the disease, such as the effects of tobacco, which began to be imported into Britain in the 16th century with the colonising of the Americas.
The researchers also point to the cancerous effects of pollutants that have become ubiquitous since the industrial revolution of the 18th century, as well as the possibility that DNA-damaging viruses are now more widespread with long-distance travel.
The skeletal remains investigated for the latest study came from three cemeteries within the medieval centre of Cambridge and three near villages outside the city.
Only remains with an intact spinal column, pelvis and thigh bones were examined, as modern research indicates these to be the bones most likely to contain secondary growths in people with cancer.
The team inspected and scanned the remains of 96 men, 46 women, and an individual of unknown sex, finding signs of cancer in the bones of five individuals – 3.5% of the sample.
Researchers reached their estimate on the basis that CT scans detect bone metastases around 75% of the time, and only a third to half of cancer deaths involve spread to the bone.
However, they caution that the sample size is inevitably limited and diagnosing cancer in those lain dead for many centuries is challenging.
“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,” added Dr Mitchell.
The research is published in the journal Cancer.