The Papanicolaou test , cervical smear , cervical screening , or smear test ) is a method of cervical screening used to detect potentially precancerous and cancerous processes in the cervix or colon . Abnormal findings are often followed up by more sensitive diagnostic procedures if warranted, interventions that aim to prevent progression to cervical cancer. The test was independently invented in the 1920s by the Greek physician Georgios Papanikolaou and named after him. A simplified version of the test was introduced by the Canadian obstetrician Anna Marion Hilliard in 1957.