The World Health Organization (WHO) has issued new guidance recommending the use of p16 immunohistochemistry (IHC) testing to improve the detection of pre-cancerous cervical disease. In doing so, WHO is the first global organization to issue written recommendations on the use of p16 after the College of American Pathologists (CAP) and the American Society for Colposcopy and Cervical Pathology (ASCCP) provided similar guidance in 2012.

Traditionally, the evaluation of cervical tissue samples has been performed using the slide-based hematoxylin and eosin (H&E) stain; however, this method of interpretation is subjective and diagnostic variability from pathologist to pathologist is well documented. In some cases this variability may lead to unnecessary procedures or even false negative results.

"p16 is overexpressed in tissue specimens with transforming HPV infections and has proven to be an extremely reliable and useful marker particularly in cervical histological diagnoses," said Dr. Teresa Darragh, professor of clinical pathology at the University of California in San Francisco. "Biomarkers such as p16 help give objective evidence to support our H&E diagnoses. They add 'science' to the morphological 'art' of interpretation."

Dr. Christine Bergeron, director of pathology and cytology at Laboratoire Cerba and co-author of the WHO recommendations, said, "Diagnostic studies have demonstrated that the use of p16 immunohistochemistry substantially improves the reproducibility and accuracy of (histopathologic) diagnoses. The adoption of the WHO recommendations and the use of p16 IHC will help address the substantial diagnostic variability present today. This will truly benefit the patient as this will help reduce unnecessary treatment but also help identify those women that should be treated."