11/12/2007 Boston, MA Scott Allen Boston Globe The almond-shaped lump on Brian Hill's throat didn't make sense to him. The doctor said it was a symptom of advanced oral cancer, but Hill had never smoked a cigarette or chewed a plug of tobacco, considered the main causes of the disease when he was diagnosed in 1997. So why was it there? Not until four years later did Hill get an explanation for his brush with death: a microbe called human papilloma virus-16 had apparently moved into his tonsils, gradually turning normal cells into cancer. Hill, now 59, had become part of a wave of relatively young nonsmokers who contracted oral cancer from the sexually transmitted virus, fueling an overall increase in new cases. Viruses such as human papilloma may be the most overlooked bad guys in the war on cancer, silent invaders that contribute to more than a dozen malignancies and may cause 15 percent of the cancer cases worldwide each year. "What we know about HPV-16 as a cancer causer is just the tip of the iceberg," said Hill, founder of the Oral Cancer Foundation, which funds research for a disease that strikes 34,000 Americans annually and is caused by the same virus that can lead to cancers of the cervix, vulva, anus, and penis. The cancer toll from germs - both viruses and bacteria - may turn out to be higher as researchers discover more of these elusive microbes and how they do their grim work. Currently, scientists [...]