The story of our understanding of cervical cancer and its primary cause, HPV, is intriguing. It involves prostitutes, nuns, and a group of second wives, as well as generations of dedicated researchers. Almost a hundred years ago, epidemiologists began to note a curious phenomenon: cervical cancer was common in prostitutes, but extremely rare in nuns – with the exception of nuns who had been sexually active before entering the convent. They also observed that the rate of cervical cancer was alarmingly high among women who were married to men whose first wives had died of cervical cancer. From these clues, scientists deduced that cervical cancer was caused by a sexually transmitted agent. It was not until the late 1970s, however, that German researchers identified HPV, long known to cause both cutaneous and genital warts, as the agent in question.
In the 1980s, building on the work of the German researchers, NCI intramural researchers were instrumental in identifying the mechanism by which HPV causes cervical cancer when they found that the viral proteins E6 and E7 induce abnormal cell proliferation and tumor development. Meanwhile, NCI-funded epidemiologic studies in different populations around the world were confirming a causal link between cervical cancer and HPV infection.