HPV is complex, is biologicall different as Cheyrl mentioned, and its treatment success may have to do with oncogenes E6, E7, pathway expressions, and tumor suppressor genes, like p53, that are different than tobacco or alcohol related cancer. I'm not fully sure, and I don't know if the medical community fully knows for sure either, but it is difficult to understand unless you are a biologist or scientist lol.

Here are some reported facts, and this may even have changed with current data, studies.

80 percent or more of the population has been exposed to HPV. 35 percent of all H&N cancers, and 77 percent of tonsil cancer can harbor HPV, with 66 percent being HPV-16, and the oropharynx is 6x more likely to demonstrate HPV postive than other sites, and has now replaces tobacco as the leading cause of Tonsil Cancer. If tonsil cancer spreads locally, it often does to the tongue, soft palate or nasopharynx, and often to the lymph nodes.

There are studies showing an increased risk of Oropharyngeal cancer among spouses of women who have a history of dysplasia attributed to HPV, and an increased risk of tonsil cancer among HIV positive men, and an increased risk of tonsil cancer in people with a history anogenital cancer.

Also, with Head and Neck cancer there is a high risk of secondary cancer, either synchronous or metachronously, so dr visits, physical exam, and diagnostic tests are important for suspicions of changes.