In 40-50% of cases, the disorder has been linked with germline mutations in the CDKN2A gene, which codes for p16 (a regulator of cell division).
The biology of HPV+ OPC is distinct of HPV- OPC with P53 degradation (inactivated by E6 instead of by genetic mutation), pRB pathway inactivation (by E7 instead of Cyclin D1 amplification), and P16 upregulation (over-expression of p16 instead of inactivation due to reduced negative feedback from pRB).
•
HPV OPC is associated with expression level of the E6/E7 mRNAs and of p16.