People who have had 10 or more sexual partners during their lifetime may have increased odds of being diagnosed with cancer, a study suggests.

Women, in particular, have nearly twice the risk when they have had 10 or more past partners compared with when they had one or none, researchers report in BMJ Sexual and Reproductive Health.

While the study team expected to find an association between number of sexual partners and cancer, they were surprised to find a gender difference.

“It is interesting the risk is higher in women when compared to men,” said study co-author Dr Lee Smith (PhD), a reader at the Anglia Ruskin University in Cambridge, UK.