HPV can infect the mouth and throat and cause cancers of the oropharynx (back of the throat, including the base of the tongue and tonsils). This is called oropharyngeal cancer. HPV is thought to cause 70% of oropharyngeal cancers in the United States. It usually takes years after being infected with HPV for cancer to develop. Marked overexpression of p16 is an effective surrogate marker for HPV status and is a very strong prognostic marker as an individual test. It should be performed on all new oropharyngeal SCC specimens. Overall 5-year survival for p16-positive cases is approximately 80% compared with 40% to 50% for negative ones. The overall agreement between p16 and consensus diagnosis was 96.1% (Kappa=0.90, P<0.001), which were higher than those of Ki67 and consensus diagnosis. All of the p16 positive cases were also positive for Ki67, but none of the p16 positive cases were negative for Ki67 (table 1). The agreement between Ki67 and p16 was higher than Ki67 and Immunohistochemistry has become an essential ancillary examination for the identification and classification of carcinomas of unknown primary site (CUPs). Over the last decade, the diagnostic accuracy of organ- or tumour-specific immunomarkers and the clinical validation of effective immunohistochemical panels has improved significantly. The .gov means it's official. Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you're on a federal government site. The p16 immunostain was positive in all cellular schwannoma cases, and the majority of these cases contained patchy expression, while p16 was completely lost in 82 (73. All the childhood melanoma cases were associated with loss of p16 without any correlation with their Breslow thickness whereas all the Spitz nevi and benign melanocytic nevi had strong positive nuclear and cytoplasmic expression of p16 staining. We found a statistically significant difference in p16 expression, mitotic counts, and Ki-67 index .

what does p16 positive mean