p16 protein expression and correlation with clinical and pathological features in osteosarcoma of the jaws: Experience of 37 cases.

Background: In literature, no markers have been reported as predictive and prognostic factors in osteosarcoma of the jaw.

Methods: A retrospective analysis of p16 expression was performed in 37 patients with high-grade osteosarcoma of the jaw to investigate its potential prognostic and predictive value.

Results: p16 positivity was found in 56.7% of cases. The absence of p16 expression was associated with an adverse disease-free survival (P = .003). At the multivariate Cox regression, positive margins were the only independent factor. In the subgroup of 17 patients who underwent neoadjuvant chemotherapy, a significant association was noted between p16 expression and pathological response to chemotherapy (P = .015) and the negativity of p16 increased the risk of negative outcome (P = .01).

Conclusion: Our data indicate that the wide surgical margin is the most important prognostic factor. The expression of p16 confers greater sensitivity to chemotherapy and its loss of expression is associated with a worse prognosis.