Stereological estimation of nuclear volume and other quantitative histopathological parameters in the prognostic evaluation of supraglottic laryngeal squamous cell carcinoma

Abstract

The aim of this study was to investigate various approaches to the grading of malignancy in pre-treatment biopsies from patients with supraglottic laryngeal squamous cell carcinoma. The prospects of objective malignancy grading based on stereological estimation of the volume-weighted mean nuclear volume, nuclear Vv, and nuclear volume fraction, Vv(nuc/tis), along with morphometrical 2-dimensional estimation of nuclear density index, NI, and mitotic activity index, MI, were investigated and compared with the current morphological, multifactorial grading system. The reproducibility among two observers of the latter was poor in the material which consisted of 35 biopsy specimens. Unbiased estimates of nuclear Vv were on the average 385 microns3 (CV = 0.44), with more than 90% of the associated variance attributable to differences in nuclear Vv among individual lesions. Nuclear Vv was positively correlated with MI, negatively with NI, whereas no correlation with Vv(nuc/tis) was found. No relationship between nuclear Vv and the morphologically interpreted degree of nuclear dedifferentiation was demonstrated. Nuclear Vv showed no differences between lesions in different clinical T-stage of disease. None of the investigated categorical and quantitative parameters (cutoff points = means) reached the level of significance with respect to prognostic value. However, nuclear Vv showed the best information concerning survival (2p = 0.08), and this estimator offers optimal features for objective malignancy grading. Further analyses of larger series of patients are needed to establish the prognostic value of nuclear Vv for objective malignancy grading of supraglottic laryngeal squamous cell carcinoma.