Prognostic factors in head and neck cancer: histologic grading, DNA ploidy, and nodal status

Histopathologic malignancy score and DNA ploidy were investigated as prognostic factors for 72 cases of squamous cell carcinoma of the head and neck (HNSCC). The malignancy grading was based upon four different morphologic characteristics for the tumor cell population and four characteristics for the tumor-host relationship. DNA ploidy was determined through flow cytometry on fresh-frozen tumor samples. The median malignancy score was 20, with 71% of the tumors scoring less than 20 being diploid and 68% of the tumors scoring greater than or equal to 20 being nondiploid (p = 0.003). Univariate analysis revealed that tumors scoring less than 20 and diploid tumors had a significantly higher proportion of complete response and better survival as compared to tumors scoring greater than or equal to 20 and nondiploid tumors, respectively. There was a tendency toward better survival among patients without regional metastasis (N0) as compared with patients with regional spread (N+), whereas the other single factors, patient age, clinical stage, histologic grade, and tumor size did not correlate with prognosis. In N+ patients both malignancy score and DNA ploidy were predictive for survival, whereas in N0 patients only malignancy score was related to prognosis. A multivariate analysis showed that the combination of malignancy score and nodal status were the strongest predictors for survival. DNA ploidy did not contribute further information in this test, due to its close relation with the histopathologic malignancy score.