Cervical cancer is the leading cause of cancer death in women in low income countries. Worldwide, cervical cancer is the third most common cancer in women, causing more than 270,000 deaths a year. Currently, about 500,000 new cases worldwide are reported each year. Cervical cancer begins at least 99.7% of the time with infection by the human papilloma virus, commonly called HPV. HPV infection is contracted at some point by more than half the population but the vast majority of all HPV infections result in a temporary infection that resolves spontaneously over a few years (see reference). A small minority of such infections will progress and become cervical cancer. The changes that create abnormal cell structures may be detected and cured over the slow course of development before invasive cancer occurs. Significant abnormal cell changes -- cervical cancer precursors -- detected in screening are completely curable. For the last fifty years, the Pap test has been the nearly universal screening tool in high income countries.
The limitations of the Pap test result from inadequate cell collection and from unsatisfactory laboratory analysis. In the United States, Pap test screening has reduced cervical cancer deaths by 70% since the 1950s, but the Pap test is limited in its capabilities. Two million women a year in the United States receive an ambiguous reading from their Pap tests each year. The follow up cost to clarify such a result is high and unnecessary anxiety is created.
For many reasons, cervical cancer is more widespread in low income countries and screening by the Pap test is not a viable option. Laboratory infrastructure is inadequate in much of the world. The technical limits inherent in the Pap test restrict improvement of that technique even in high income countries. There is also a disturbing trend in high income countries -- after fifteen years of stability, cervical cancer has recently more than doubled in
the under-40 age group in Finland (see reference). Earlier onset of sexual activity, increased smoking among youth, the upsurge of a new HPV strain (HPV 45), and the increased prevalence of chlamydia as a disease promoter are probably all contributing causes.
An improved screening method for cervical cancer precursors is needed -- a technique which can be applied worldwide, without the need for specialized practitioners or advanced laboratory facilities.