HPV TESTING HELPFUL FOR ASC-US

November 2, 2010 (San Francisco, California) — A new study from an inner-city hospital in Atlanta, Georgia, of 348 patients with a diagnosis of atypical squamous cells of undetermined significance (ASC-US) confirms that high-risk human papillomavirus (HPV) assay testing is essential for pinpointing patients with high-grade dysplasia who need follow-up treatment, according to research presented here at the American Society for Clinical Pathology (ASCP) 2010 Annual Meeting.

In the retrospective study, high-risk HPV testing was able to identify all patients with cervical intraepithelial neoplasia (CIN) 3 lesions and almost all patients (96%) with CIN 2 lesions, using the Hybrid Capture 2 (HC2) HPV assay for detecting cervical cancer precursor lesions on SurePath specimens.

"These are patients who don't come in for regular testing and tend to present with pretty advanced disease. We wanted to evaluate patients with a diagnosis of ASC-US in this population to see the rate of high-risk HPV positivity," said presenting researcher Beth Chastain, MD, from Emory University School of Medicine and Grady Memorial Hospital in Atlanta.

"If we can give these patients an HPV test during their initial visit, we can assess where they are at and get them treated more easily," Dr. Chastain said. "It's important not to let these patients fall through the cracks."

From 2006 to 2008, data collected from SurePath Pap tests interpreted as ASC-US on high-risk HPV testing and histologic follow-up — such as cervical/cone biopsy, endocervical curettage, and hysterectomy — were analyzed.

At Grady Hospital, Dr. Chastain reported that the rate of ASC-US is 11.5%, which is twice the national average. Among patients with ASC-US, 63% were high-risk HPV-positive. In this subgroup, 54% had high-grade dysplasia, and the rate of severe dysplasia/carcinoma in situ was 10.4%. In contrast, no patients who tested high-risk HPV-negative had severe dysplasia/carcinoma on follow-up.

Of 220 high-risk HPV-positive samples, 60 patients (27.3%) had negative histology on follow-up, a finding that might be explained by regression or limited sampling, the researchers say. These conflicting results suggest a need for further follow-up of these patients, Dr. Chastain and colleagues conclude.

"The ALTS [ASC-US/LSIL Triage Study] showed unequivocally that you should do a clinically valid test for high-risk HPV types to distinguish patients in the ASC-US population who are at risk for CIN 3 and those who aren't," said Mark Stoler, MD, professor of pathology and gynecology and associate director of surgical pathology and cytopathology at the University of Virginia Health System in Richmond. Dr. Stoler is president of the ASCP.

"This is another confirmatory study that shows us that with a diagnosis of ASC-US, the standard of care is to do an HPV test," he added. Dr. Stoler noted that although the ALTS trial was performed using ThinPrep Pap tests, the Grady Hospital study adds to the developing literature concerning the clinical validity of SurePath liquid-based Pap tests, he said.

Dr. Chastain has disclosed no relevant financial relationships. Dr. Stoler reports being a consultant for both BD, the manufacturer of SurePath, and Qiagen, the manufacturer of HC2.

American Society for Clinical Pathology (ASCP) 2010 Annual Meeting: Abstract 13. Presented October 28, 2010.