Cervical cancer kills about 4,000 women per year. Although those numbers are lower than they have been in the past, almost all of these deaths are entirely preventable. Cervical cancer is cased by certain strains of the human papillomavirus, or HPV, which is transmitted by sexual contact, causing normal cells to become cancerous over time. Cervical cancer has become much less deadly in recent years, due, in part, to more frequent and sophisticated screening methods. But according to a new study from the American College of Physicians, too frequent screenings for low-risk patients can cause more harm than good.