The sexual revolution is producing a new wave of throat and tongue cancers among middle-aged people, who are falling victim to a rare side effect of the "common cold of sexually transmitted infections". 
A growing number of Australians with oropharyngeal cancer are testing positive to the human papillomavirus (HPV), suggesting it has caused their disease rather than smoking or heavy drinking.
Oropharyngeal cancer is usually found in the back third of the tongue or the tonsils. In 2014, about 125 Victorians were diagnosed with it. Most were men.
An Australian study of 515 patients diagnosed with the condition between 1987 and 2010 found that the proportion of people with an HPV-related diagnosis increased from 20 per cent between 1987 and 1995 to 64 per cent between 2006 and 2010.
Over the same period, the proportion of people diagnosed with throat cancer who had never smoked increased from 19 per cent to 34 per cent, suggesting HPV may overtake smoking and drinking as a cause of the cancer in future.
American doctors say more oral sex following the sexual revolution of the 1960s probably spread HPV to more people's mouths and throats.
Actor Michael Douglas said he believed oral sex was to blame for his HPV-related throat cancer in 2013.
But Dr Matthew Magarey, an ear nose and throat surgeon at Epworth and Peter MacCallum hospitals in Melbourne, said while HPV-related throat cancers were occurring in more people aged 40 to 60, it should not necessarily be associated just with oral sex because scientists believe HPV may be transmitted through kissing or simple hand to mouth contact as well.
Up to 80 per cent of the adult population is thought to have had some sort of HPV infection during their life (there are more than 100 strains) and most of them will not have experience any symptoms. Many people clear the virus within months of getting it.
Dr Magarey said a tiny proportion of people will get an HPV-related cancer, such as cervical, anal, or throat cancer. He said HPV in the throat probably took 30 to 40 years to turn into a cancer.
He said treatments were getting better for the cancer, which has a high survival rate if found early. Depending on the circumstances of the cancer, radiation, chemotherapy and sometimes surgery are used to treat it.
While the surgery has been long and complicated in the past, Dr Magarey said a new robotic procedure available at Peter Mac and Epworth was helping surgeons remove cancers more precisely and in less time.
This was reducing long-term recovery problems such as difficulty eating and drinking and swallowing.
Dr Magarey said the most common first sign of throat cancer was a lump in the neck that persists for more than two or three weeks. Symptoms can also include a sore throat that persists for more than three weeks and difficulty swallowing.