The Pap Smear Test is the most successful cancer screening technique in history. It was named after its inventor, Dr. George Papanicolaou. While Dr. Papanicolaou first presented his findings that uterine cancer could be diagnosed by means of vaginal smear in 1928, it wasn't until his book "Diagnosis of Uterine Cancer by the Vaginal Smear" was published in 1943 that his work became widely known and accpeted. The book describes the process of preparing a cervical smear and the cytologic changes that are seen as cervical cells change from normal, to pre-canceruos, to cancer. Since World War II , the Pap Smear Test has become the most widely used cancer screening method in the world.

Cervical Cancer screening using the Pap Smear Test can detect precancerous changes before the existence of any symptoms. Because Pap Smear screening can help detect abnormal cells before Cervical Cancer develops, regular Pap Smear screening makes Cervical Cancer preventable. Regular Pap Smear screening allows for the detection and treatment of precancerous cervical lesions, called "dysplasia," before the development of Cervical Cancer.

Most abnormal cells detected through Pap Smear Test screening are not cancerous. Some, however, may develop into cancer over time. Such precancerous cells.

The two types of precancerous cells detected on Pap Smear Test screening are referred to as LSIL and HSIL, low-grade squamous intraepithelial lesions and high-grade squamous intraepithelial lesions. A "Squamous" cell is a type of flat cell that covers much of the cervix, vagina, and vulva. The protective layer of cells is called the "epithelium" and an area with the epithelium is referred to as "epithelial." A "lesion" is an area of abnormality.

LSIL Low-grade squamous intraepithelial lesions are are not cancer, but minor cell changes on the surface of the cervix. LSILs are common, especially in young women, and often are caused by HPV infections. LSILs resolve on their own in most cases, even without treatment. In approximately 10-25% of cases, however, LSILs develop into high-grade lesions that may lead to cancer.

HSIL High-grade squamous intraepithelial lesions on a Pap Smear Test result reflect a finding of moderate or severe dysplasia and always require further evaluation with colposcopy and biopsy. While HSILs are not cancer, they may lead to Cervical Cancer without proper treatment.