Association of BMI-1 and p16 as prognostic factors for head and neck carcinomas

BMI-1 is an upstream repressor of tumor suppressor p16 and their inverse expression patterns have been linked with patient survival in OPSCC. In this material only p16 remained a relevant prognostic marker in OPSCC.

HNSCC tumors carry variable phenotypes and clinical outcomes depending on their anatomical location. In OPSCC, expression of tumor suppressor p16 is used as a surrogate marker of HPV infection and has prognostic value. There are no good prognostic biomarkers for HNSCC tumors of other anatomical locations.

To study the expression patterns of p16 and BMI-1 in not only oropharyngeal but also oral, hypopharyngeal, and laryngeal squamous cell carcinomas and to clarify their putative connections with clinical parameters, survival, and each other.

Hospital records on 130 patients (59 OPSCC, 18 OSCC, 20 HPSCC, and 33 LSCC) diagnosed between 1997-2008 at the Helsinki University Hospital, Finland, were reviewed. BMI-1 and p16 expressions were studied by immunohistochemistry.

Sixty-eight per cent of OPSCC expressed p16 and expression correlated with lower age, lower T- and higher N-category, and with improved OS and DFS. BMI-1 expression was most prevalent in OPSCC and LSCC, but had no clinical correlations. No correlation between p16 and BMI-1 expression was found.