 Condoms may also be useful in treating potentially <unk> cervical changes . Exposure to human <unk> , even in individuals already infected with the virus , appears to increase the risk of <unk> changes . The use of condoms helps promote regression of these changes . In addition , researchers in the UK suggest that a hormone in semen can <unk> existing cervical cancer , condom use during sex can prevent exposure to the hormone . 
