According to a study, almost 100 percent of oral cancer cases from 1973 to 2004 were linked to HPV (human papillomavirus) infection in patients in their 40s. The American Cancer Society also stated that close to 40% of the 35,000 oral cancer cases were associated with HPV. These patients tend to be young, probably in their late 30s to early 40s, non-smokers and non-alcoholics, but in every case HPV-16 is found in their tissues and biopsies, infected due to direct contact with the source HPV or the virus is dependent on the pathogen. The researchers believe that HPV was found in the patients’ mouths as a result of oral sex or kissing. And HPV is not transmitted through the bloodstream; instead, the proteins in HPV damage healthy cells in that area. Once those healthy cells can’t be repaired, then these viruses will keep replicating.