"Colposcopy is both expensive -- $200 to $500 per patient -- and invasive, requiring examination and painful biopsy," he says. "Given that only a small percent of minimally abnormal Pap smears result in clinically significant lesions, most of this expense is unnecessary. In addition, depending on the site of biopsy, results may be misleading and miss a clinically important lesion."
Boggess adds: "Identifying an alternative screening method other than colposcopy that could better predict which minimally abnormal Pap smears are more likely to progress to pre-invasive or invasive cancer, would significantly decrease the expense and increase the efficacy of cervical cancer screening."
Some tantalizing earlier research findings are leading Boggess and his UNC colleagues to view telomerase testing as a possible solution.
The major cause of cervical cancer and its pre-invasive lesions is HPV - human papillomavirus. It is found in cervical cancers worldwide. But the usefulness of HPV testing for the HPV types that are associated with cervical cancer has proved only of limited clinical value.
Boggess's collaborator, Dr. William Kauffmann, professor of pathology and laboratory medicine, has infected human cells with DNA from highly oncogenic HPV strains. "Over time, you see increased amounts of genetic instability that occurs as chromosomes shorten, as telomeres shorten," Boggess says. "Depending on what chromosomal material is lost, some cells will acquire telomerase, which stabilizes chromosomes and produces immortal cell lines."
Thus, instead of an unstable cell that eventually dies, what results is a cell line that can divide indefinitely. And depending on its genetics can become cancer.
Two years ago, the UNC researchers decided to determine if the test-tube
findings would apply in people. They took extra Pap smears from 120 women who
had been referred for colposc
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Contact: Lynn Wooten
Lwooten@unch.unc.edu
919-966-6046
University of North Carolina School of Medicine
30-Sep-1999