The human papillomavirus (HPV) is linked to a three-fold higher risk of esophageal cancer, according to a new study from the University of New South Wales.

Scientists came to the conclusion after comparing patients with esophageal cancer to those without it. Using tissue samples from their tumors, researchers tested to see whether HPV was present. Out of the 21 groups analyzed, 35 percent of patients with the cancer had HPV, Reuters reports.

"This study is the most definitive contribution to date about a question which has defied answers for 30 years: the association of HPV with OSCC," Surabhi Liyanage, the study’s lead author and her colleagues said referring to the specific kind of cancer used in the study: esophageal squamous cell carcinoma.

Despite the high proportion of esophageal cancer cases with HPV, Liyanage warns that it doesn’t mean the virus is present in all cases, she told Reuters. If anything, the study results point to the growing need to vaccinate children of both genders with Gardasil and Cervarix – two vaccinations intended to prevent HPV, Liyanage said in a statement.

HPV is the most commonly sexually transmitted disease which is spread through genital contact, according to the U.S. Center for Disease Control. Each year an estimated 26,200 new cancer cases are caused by HPV.

While the virus causes nearly all cervical cancers and many genital cancers – there has been much debate as to its role in causing esophageal cancers.

"Smoking and alcohol are the main causes, as well as the consumption of extremely hot liquids, lots of red meat and possibly environmental toxins in the diet," Liyanage said pointing to other known causes of esophageal cancer.

Further studies will need to be performed to prove whether or not HPV contributes to esophageal cancer. If that is the case, the vaccines could prevent the cancer, Liyanage said. "However, this needs to be studied further. The benefits of cancer-preventing vaccines are not seen immediately, but after many years following vaccination," Liyanage said.

One of the most well-known cases of esophageal cancer comes from Hollywood actor, Michael Douglas. The 68 year-old who was diagnosed with throat cancer in 2010 said in a recent interview that his cancer came from HPV.

“Without wanting to get too specific, this particular cancer is caused by HPV, which actually comes about from cunnilingus," Douglas told The Guardian referring to how oral sex may have contributed to his diagnosis.

Later, spokesman Allen Burry said Douglas was talking about one of many potential causes of his cancer. "In a discussion with the newspaper, they talked about the causes of oral cancer, one of which was oral sex, which is noted and has been known for a while now," Burry told the Associated Press.

Esophageal cancer is the eighth most common cancer in the world and is responsible for an estimated 400,000 deaths worldwide, researchers said in the study published in the online journal PLOS ONE. In the U.S., an estimated 15,000 people die each year from the disease, according to the National Cancer Institute.

"One of the main issues is this form of esophageal cancer is usually diagnosed quite late and so has a very high mortality," Liyanage said in a statement.

Douglas says he’s grateful that he is a survivor.

"It's been a rough few years, the cancer break. But I'm back with a vengeance,” Douglas said. ”I feel blessed and fortunate that I still have a career. I feel blessed and fortunate that I'm even alive."

Medicine Cancer