Sexual "liberation" may have fuelled cancer rates
The arrival of the "swinging 60s" may have heralded a rise in sexually-transmitted cancers, say researchers.
Rates of anal, vulval and vaginal cancers rose for "baby boomers" born in the decades after the Second World War.
The culprit is the human papillomavirus (HPV), acquired during sex, said the King's College London study.
Up to three out of four people will be infected, it estimates. The British Journal of Cancer report says changes in sexual habits may be the cause.
HPV has been implicated in a number of cancers, including cervical, anal, vulval, vaginal and penile - although the diseases can be caused by other factors too.
Some estimates suggest that up to three out of four people will be infected with HPV at some point in their lives, although the immune system is normally able to destroy it.
However, if an infection is persistent, it may cause cells to become cancerous.
The King's College London study, using figures from a cancer database, suggests that rates of some of these cancers rose quickly for the generations born in the 1950s and 1960s.
There has been a steady rise in anal cancer rates over that period in both men and women, but with women born in the 1960s three times more likely to develop it than those born 20 years earlier.
Although vaginal and vulval cancer rates have fallen away in modern generations, they are higher in the 1960s generation of women compared with those born in the first half of the 1940s.
Cervical cancer is the most common cancer linked to HPV.
Rates of the disease stayed steady during the period studied, a fact credited mainly to the cervical screening programme.
The risk to future generations from the disease is likely to fall further after the introduction of a vaccine to some types of HPV.
The researchers said they believed that both changes in sexual practices, and a greater exposure to HPV were the likely cause for those increased rates.
Separate studies have suggested a rise in female anal intercourse involving the 1960s generation.
Dr David Robinson, who led the study, said: "These results have revealed a snapshot of just how much rates of these cancers have increased in the post war generations.
"For anal cancer, rates are now higher in women than in men - however, programmes of vaccination against HPV, whilst aimed primarily at reducing the burden of cervical cancer, may also help to reduce the incidence of cancers at these other sites."
Dr Lesley Walker, from Cancer Research UK, said that it was important people understood the dangers linked to HPV.
"Using a condom will lower the risk of exposure to the virus. HPV vaccines are an important advance for future generations, but the cervical screening programme remains vitally important in detecting any changes that might lead to cancer."