First symptoms Michael Douglas experienced before discovering cancer caused from oral sex

The earlier cancer can be caught, the better, and Michael Douglas is seeking to raise awareness of oral cancers by sharing his symptoms.

The Hollywood A-lister shocked fans with the revelation he had stage four throat cancer.

He hasn't shied away from talking about possible causes too, saying his was caused by oral sex.

Douglas has been candid about his past with addiction and substance abuse, and back in 2013, he told The Guardian that his cancer was caused by oral sex, and blamed it on 'cunnilingus'.

"Ah, without getting too specific, this particular cancer is caused by something called HPV [human papillomavirus], which actually comes about from cunnilingus," he said at the time.

He has since denied making the comment, however, the publication insisted he did and confirmed they had an audio recording and released a full transcript of what was said.

Michael opened up about the symptoms and potential causes of his throat cancer (Arnold Jerocki/Getty Images)

According to the Cleveland Clinic, HPV can be responsible for oral cancer, and it can also cause cervical cancer too, and is the most common viral sexually transmitted infection in the US.

There are more than 100 variants of HPV, and around 15 types of HPV are linked to increased cancer risk.

At an awards ceremony, he said: “I never expected to become a poster boy for head and neck cancer, but, if after what started out as trying to answer a couple of questions about the suspected sources of this disease results in opening up discussion and furthering public awareness, then I’ll stand by that.”

He revealed he first started experiencing problems back in 2010.

Michael has teamed up with the Oral Cancer Foundation to raise awareness, and shared information about the symptoms he was experiencing, with the hope of helping somebody else.

He recalled experiencing a sore throat that persisted for a long time, and he kept visiting the doctor, with no joy.

Doctors repeatedly diagnosed him with a throat infection.

It wasn't until he saw a doctor friend in Montreal that the cause was spotted.

He believes his cancer was caused by HPV (Francois Durand/Getty Images)

"I will always remember the look on his face," he recalled.

"He said: 'We need a biopsy.' There was a walnut-size tumor at the base of my tongue that no other doctor had seen."

He was then diagnosed with IV squamous cell carcinoma oral cancer, and originally feared he would have to have part of his jaw removed.

The chosen treatment was radiation and chemotherapy treatments, but according to the charity, he is now 'cancer free and in good health'.

The side effects of the treatment were horrifying, with burns to his palate.

He did not want a feeding tube, and lost a whopping 20kg (45 pounds) on a liquids-only diet and said he was 'very weak'.

"That's a rough ride. That can really take it out of you," he said. "Plus the amount of chemo I was getting, it zaps all the good stuff too. It made me very weak."

The Fatal Attraction actor added: "I did worry if the stress caused by my son's incarceration didn't help trigger it. But yeah, it's a sexually transmitted disease that causes cancer. And if you have it, cunnilingus is also the best cure for it."

However, a consultant and head and neck surgeon in London, Mahesh Kumar, disputed Michael's claim that more sex was the cure: "Maybe he thinks that more exposure to the virus will boost his immune system. But medically, that just doesn't make sense."

According to the Oral Cancer Foundation, approximately 48,250 people in the US will be newly diagnosed with oral cancer each year.