Morphohistometric analysis of advancing tumor fronts in malignancies associated with oral submucous fibrosis

The precancerous nature of oral submucous fibrosis (OSF) was first postulated by Paymaster(1956) [1], who described the development of slow growing squamous cell carcinoma in one third of OSF cases seen at the Tata Memorial Cancer Hospital, Bombay. The precancerous potential was also emphasize by other authors, [2-5] based on clinical and epidemiological grounds. The frequency of malignant change in patients with OSF ranges from 3% to 6%. In a 10 year follow up study in Kerala, India, Gupta et al[6] reported malignant transformation in 2.3% of patients with OSF. Utilizing this material and additional material from the same area, with a 15 year follow up, Pindborg et al [3] demonstrated a malignant transformation rate of 4.5%. From the same area and patient group, 66 patients with OSF were followed up for a period of 17 years by Murti et al [4], who recorded a malignant transformation rate of 7.6%. With a longer follow-up of the same group, the malignant transformation rate could increase still further. Surveys in various cancer hospitals in India revealed a 15-20% frequency of oral cancer patients in India has strengthened the postulated link between the two. Squamous cell carcinoma accounts for the majority of oral tumors associated with OSF. Although the clinical outcome is influenced by and large by stage of tumor and histopathological grading of the disease at presentation, the established systems of staging (TNM-UICC) [9] as well as histopathological gradings are all inherently handicapped as useful prognostic predictors of the disease. Although a large number of studies of new potential molecular markers have been carried out, none of these have gained general clinical acceptance. The celluler characteristics of the deep invasive fronts of head and neck squamous cell carcinoma are the most important indicators for its invasive and metastatic capabilities and thus provide more prognostic information than the central and superficial parts of the same tumour. [12] On the basis of such findings a new, simple, malignancy grading has an acceptable interobserver reproducibility before and after calibration by the Pathologists. An assumption, which was largely unfounded, among clinicians in India is that squamous cell carcinoma associated with OSF behaves more refractory to treatment and difficult to manage. This study aims at addressing this issue by retrospectively examining the invasive tumor fronts of epithelial neoplasms associated with OSF and the non-associated tumors. Integration of these variables into a prognostic system will better reflect the biologic diversity of oral cancer and help predict more accurately the therapeutic outcome and overall survival of this group of affected individuals.Dept. of Oral Pathology Govt. Dental College, Trivandrum, Indi