Researchers at Johns Hopkins Kimmel Cancer Center discovered that the sexually transmitted virus that causes some cervical cancers could also cause cancer in the upper throat and head.

These types of cancer include tumors in the mouth, tongue, nose, sinuses, throat and lymph nodes in the neck.

Dr. Marura Gillison, MD, PhD and colleagues studied 240 patients diagnosed with head and neck cancer at the outpatient otolaryngology clinic of the Johns Hopkins Hospital from May 2000 through June 2006.

Of the 240 cases, 92 (38 percent) were found to have human papillomavirus-pozitive tumors. HPV was most often linked to throat cancers in younger, married college graduates. The risk increased with the increased number of oral sex partners and marijuana use.

Other head and neck cancers (not related to HPV) are more often associated with smoking tobacco, alcohol use and poor oral hygiene, suggesting they may be a separate disease.

“Our results indicate that HPV-positive and HPV-negative head and neck cancers have different risk-factor profiles and should be considered two distinct diseases. They just happen to occur in the same place,” Gillison said.

She also added that the findings have to be confirmed by further studies on how marijuana use is linked to throat and head cancers.

“It’s possible that other behaviors linked with marijuana use could be the real culprit, and our results will need to be confirmed,” she said. Chemicals in marijuana called cannabinoids could affect the immune system’s ability to fight a virus.

According to the Centers for Disease Control and Prevention, about 20 million Americans are currently infected with HPV and another 6.2 million people become infected each year. At least 50 percent of all sexually active men and women will have at least one genital HPV infection throughout their lives.

The findings appeared in the March 18 issue of the Journal of the National Cancer Institute.