DNA index, cellular proliferative activity and nucleolar organizer regions in cancers of the larynx

Ki-67 expression predicts radiosensitivity in oral squamous cell carcinoma

The prognostic relevance of Ki-67 expression in oral squamous cell carcinoma (OSCC) is still controversial. As proliferating cells are more susceptible to ionizing radiation, the authors investigated if a high proliferation rate reflected by Ki-67 expression, predicts radiosensitivity in OSCC patients. In 52 patients with OSCC who received primary surgery followed by radiation therapy, the proliferation rate was assessed by Ki-67 immunhistochemistry and correlated to recurrent free survival and overall survival. Low proliferative carcinomas showed a significantly shorter mean time to recurrence of 27.5 months compared to 49.5 months of high proliferative tumours (p=0.048). The 5-year survival rate of low proliferative tumours was 49% compared to 80% for high proliferative tumours (p=0.042). This study indicates that tumours with high proliferative activity are more susceptible to radiation therapy. Ki-67 might be used as a marker to predict the response to radiation therapy in patients with OSCC.

Prognostic significance of DNA cytometry in combination with AgNOR investigation

CONCLUSION

While most results concerning DNA and nucleolar organizer region (AgNOR) parameters fit with previous studies, the percentage of aneuploidy looks like a promising prognostic parameter. The observed intratumoral heterogeneity could represent a possible source of conflicting and inconsistent results.

OBJECTIVES

The aims of our study were to determine the prognostic relevance of different DNA and AgNOR parameters in laryngeal squamous cell carcinoma (SCC) and compare these findings with established prognostic factors including tumor stage and grade, as well as the detection of possible intratumoral heterogeneity.

MATERIALS AND METHODS

Sections from 62 laryngeal SCCs were analyzed for DNA content, DNA index, S-phase, percentage of aneuploidy, and AgNOR. Of 62 samples, 31 morphologically similar tumor samples were analyzed for the same parameters in three different tumor areas defined as tumor center, invasive tumor margin, and transformation margin between tumor and normal-appearing mucosa.

RESULTS

Our study showed that DNA and AgNOR parameters correlated with T stage, lymph node involvement, and histologic grade regardless of tumor areas. Significant correlation was found between mean number of AgNOR per nucleus and percentage of aneuploidy. Clinical stage and percentage of aneuploidy correlated with survival (p<0.02). Heterogeneity DNA study revealed aneuploidy in central portions of 90% of tumors, while in margins aneuploidy was demonstrated in about half of the patients.

Gradual deregulation and loss of PCPH expression in the progression of human laryngeal neoplasia

PCPH is a gene involved in the regulation of eukaryotic cell proliferation and stress response. Recently, analyses of human and animal solid tumors and cell lines suggested that PCPH protein deregulation may participate in neoplastic progression. To test this possibility, we first examined PCPH expression in several laryngeal carcinoma cell lines by Western analysis. The results showed the presence of altered PCPH polypeptides in these cells, accompanied by the loss of the PCPH form present in normal laryngeal epithelial cells, a deregulated expression pattern similar to that reported previously. We then analyzed PCPH expression in 59 dysplastic lesions of the human larynx, representative of the mild, moderate, and severe stages of the disease. Immunohistochemical data showed that, compared with normal laryngeal mucosa, PCPH expression in the dysplastic samples was associated with areas of epithelial cell maturation rather than with regions of increased proliferation. Furthermore, PCPH expression decreased parallel to the increase in cellular atypia of the dysplastic samples: PCPH either was expressed at very low levels or not expressed in cases of severe dysplasia/carcinoma in situ. This trend toward loss of PCPH expression along malignant progression of the larynx was confirmed by the low to null expression of PCPH in samples of invasive laryngeal carcinoma and by the complete absence of PCPH immunostaining in a laryngeal carcinoma-derived liver metastasis. These results indicated that PCPH protein analysis might allow for the distinction between grades of laryngeal dysplasia. In addition, detection of altered PCPH polypeptides by Western analysis potentially can be applied to the early identification of laryngeal squamous cell carcinoma.

Surfing prognostic factors in head and neck cancer at the millennium

The ability to reliably predict cancer outcome could tailor therapy to the aggressiveness of the tumour to achieve the best results in terms of loco-regional control, overall survival and quality of life. Retrospective and prospective clinical trials involving large series of patients have validated some predictive clinical and pathological factors, whereas the utility of many other prognostic factors has not been established. This has led to some confusion in clinical practice. In order to clarify the significance, role and cost of these prognostic factors we carried out a Medline search of all papers published between 1993 and 1998 concerning the reliability and cost of markers with prognostic significance, in head and neck squamous cell carcinoma, and assessed the results according to a number of criteria relating to reliability and cost. Regarding reliability we classified prognostic factors into: (1) those with a proven significance based on the fact that they were unanimously reported as having an independent statistical correlation with outcome and prognosis; and (2) those for which results were not unanimous, and which significance is still controversial. Cost analysis showed a substantial difference between validated tests which are of low cost and experimental tests which are expensive. Based on these data regarding both the reliability and cost of each prognostic factor, we propose guidelines for their use in clinical practice in the year 2000.