Sex, drugs and ... cancer, not violence! More specifically, sex, marijuana and head and throat cancer. The human papilloma virus (HPV) has been connected to throat cancers most often in younger, married college graduates by a study carried out by a team at Johns Hopkins Kimmel Cancer Center report and published in the Journal of the National Cancer Institute.

HPV is sexually transmitted and can induce some cervical (uterus) cancers and can also cause cancer in the upper throat, mouth, anus, penis and other locations. The team found a stronger connection between throat cancer and an increasing number of oral sex partners and marijuana use.

"Other head and neck cancers are more often associated with smoking tobacco, alcohol use and poor oral hygiene, suggesting they may be a separate disease," said lead researcher Dr. Maura L. Gillison, associate professor of oncology and epidemiology at Hopkins.

"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. More research will need to be done to clarify the relationship to marijuana use. It's possible that other behaviors linked with marijuana use could be the real culprit, and our results will need to be confirmed," said Gillison.

The researchers can only guess, for the moment, that marijuana active ingredients, the cannabinoids, could decrease the power of the immune system to kill viruses. HPV infection level has reached 20 million cases in US alone, and 6.2 million people get infected annually. This means that 50 % of all sexually active men and women will catch a genital HPV infection during their lives.

Moreover, annually 11,070 American women develop cervical cancer, and the main causing factor is HPV. Still, HPV-positive tumors are easier to treat compared to HPV-negative tumors.