Correlation of proliferative markers (Ki-67 and PCNA) with survival and lymph node metastasis in oral squamous cell carcinoma: a clinical and histopathological analysis of 113 patients

The purposes of this study were to examine the correlations between proliferation markers and survival rate in oral squamous cell carcinoma (OSCC) patients, and to evaluate the efficacy of proliferation markers in predicting lymph node metastasis. The patients' age, gender, T score, clinical stage, PCNA and Ki-67 index were analysed. Univariate analysis showed that T score had a significant influence on survival, and stage 4 group had a significantly lower survival rate. Lymph node metastasis was also a significant predictor of survival. Using a cut-off point of 25%, those patients with lower Ki-67 scores had survival advantage over those with higher Ki-67 scores. PCNA did not show any differences in survival with a cut-off point of 50%. Ki-67 and PCNA were significantly higher in the primary tumours associated with lymph node metastasis (pN+) than in those without lymph node metastasis (pN0). Multivariate analysis showed that clinical stage and Ki-67 were independent prognostic factors for survival in OSCC patients. From this result, it can be postulated that the cancer staging based on the TNM stage was a powerful prognostic variable and Ki-67 had a significant effect on the cumulative survival rate.