Nucleolar organizer regions and prognosis in glottic squamous cell carcinoma

Prognostic relevance of cell proliferation in head and neck tumors

Cell proliferative activity has been extensively investigated in head and neck tumors. Ki67/MIB-1 immunostaining, tritiated thymidine or bromodeoxyuridine labeling indices, DNA S-phase fraction, proliferating cell nuclear antigen expression, potential doubling time and analysis of the nucleolar organizer region associated proteins (AgNORs) have shown significant correlation with prognosis in 4806 cases of tumors of the oral cavity, salivary glands, pharynx and larynx. However, this was not observed in 2968 other reported cases. Discrepancies may depend on various factors: the heterogeneity of the series, which include tumors from various anatomic sites and patients treated with different therapy, and the lack of standardization of methods for assessing cell proliferation. Furthermore, none of the methods currently applied can by themselves define the actual proliferative activity, as it depends both on the proportion of cells committed to the cycle (growth fraction) and the speed of the cell cycle. Indeed, the actual proliferative activity of a tumor could well be measured by the equation [PA = Ki67 or MIB-1 scores x AgNORs], as we did in pharyngeal carcinoma. Provided that large and homogeneous series are evaluated by standardized methods, cell proliferative activity can still be regarded as an inexpensive and reliable prognostic factor in head and neck tumors.

Prognostic value of Le(y) and H antigens in oral tongue carcinomas

OBJECTIVE

To investigate the prognostic significance of the carbohydrate epitopes H and Le(y) and their relationship with proliferation and apoptosis.

STUDY DESIGN

Eighty randomly selected patients with T1-T4 oral tongue squamous cell carcinoma (SCC) were studied. Serial sections were cut from diagnostic, formalin-fixed, paraffin-embedded specimens.

METHODS

Sections were stained immunohistochemically for H antigen and Le(y).

RESULTS

Expression of H antigen was associated positively with Le(y) expression (P = .0001). Expressions of H antigen or Le(y) correlated with the proliferative markers Ki67 (P = .0442 and P = .0003, respectively) and pAgNOR > 1 (P = .0674 and P = .0047, respectively), but not with apoptotic markers such as Bax expression or the apoptotic index (AI). Tumors that expressed H antigen and high levels of Le(y) (> 50%) had a poor prognosis (P = .0006 and P = .0056, respectively). Combinations of expression of H antigen and Le(y), and either proliferative or apoptotic markers revealed an enhanced prognostic potential (P < .0001). The combination of pAgNOR score greater than 1 and H-antigen expression appeared to be the best combination to predict good prognosis.

CONCLUSION

The expression of H antigen and Le(y), especially their combination with proliferative or apoptotic markers, has prognostic value in tongue SCC.

Prognostic significance of proliferative and apoptotic markers in oral tongue squamous cell carcinomas

The prognostic impact of proliferative and apoptotic markers was studied in 85 T1-4 oral tongue squamous cell carcinomas (SCCs). Ki67 immunoreactivity and AgNOR counts, including mean AgNOR counts (mAgNOR) and the percentage of nuclei with more than one AgNOR (pAgNOR > 1), were used as proliferative parameters. The apoptotic index (AI) was assessed using the TUNEL method. Bax expression was detected immunohistochemically and scored. Bax expression correlated positively with AI (p = 0.0122). Ki67 correlated with both pAgNOR > 1 (p = 0.0042) and mAgNOR (p = 0.0189). Low Bax expression and low AI correlated significantly with the disease-free period (p = 0.0001 and p = 0.0024, respectively). High values for Ki67, pAgNOR > 1 and mAgNOR correlated with poor prognosis (p = 0.0021, p = 0.0001 and p = 0.0244, respectively). Combinations of proliferative and apoptotic parameters were stronger predictors than individual parameters (p < 0.0001). pAgNOR > 1-Bax expression appeared to be the best combination (p < 0.0001). We conclude that proliferative and apoptotic markers, especially their combinations, have prognostic value in tongue SCC.

Bax expression has prognostic significance that is enhanced when combined with AgNOR counts in glottic carcinomas

Using nucleolar organizer regions (NORs) as a proliferative marker and Bax expression as a marker for apoptosis, we have studied the individual and combined prognostic significance of these markers. Successive sections of diagnostic, formalin-fixed and paraffin-embedded specimens from 69 patients with T1-4 tumours were stained with a rabbit anti-human Bax polyclonal antibody and silver nitrate for visualization of NORs (AgNORs). After classification for staining intensity and the percentage of Bax expression, a final score resulting in four classes of increasing Bax expression was obtained. AgNOR counts were expressed as mean counts (mAgNOR) and the percentage of tumour nuclei with more than one AgNOR (pAgNOR>1). Both AgNOR parameters were grouped in three classes with increasing values. Low Bax scores correlated significantly with poor prognosis (P = 0.0106). For mAgNOR and pAgNOR>1, high values correlated with poor prognosis (P = 0.0185 and P = 0.0003 respectively). A combined parameter, for which the Bax score was subtracted from the AgNOR scores, appeared to be statistically stronger than the individual parameters (P < 0.0001). Both Bax expression and AgNOR scores, and in particular the combination of these parameters, appear to be strong prognostic markers in glottic squamous cell carcinomas.