Carcinoma of the Tongue: A Case-control Study on Etiologic Factors and Dental Trauma

Background: Carcinoma of the tongue is the most common intra-oral malignancy in Western countries.Incidence and mortality rates have increased in recent years, and survival has not improved. This study aimedto determine etiologic factors for tongue cancer with age-sex matched case-control data. Materials and
Methods:47 patients with carcinoma of the tongue referred to our oral medicine clinic between years 2005-2006 wereanalyzed and compared with control group data. The medical records , including family history of cancer,dental trauma, and history of abuse of alcohol and tobacco products was recorded for all subjects. Chi squarecomparison tests and linear regression analysis were performed using the SPSS program for statistics.
Results:Patient and randomly selected control groups each consisted of 30 male and 17 female subjects with mean ages53.2 (±12.6) and 52.6 (±11.5) years respectively. Smoking and alcohol abuse proportions were significantly higherin the patient group (p=0.0001, p<0.0001 respectively). Chronic mechanical trauma was observed in 44.7% of thepatients and 17.0% of the control group (p=0.004). Similarly, family history of cancer of any type (for the firstdegree relatives) was found to be more common in the patient group (p=0.009). On regression analysis, alcoholabuse, family history of cancer, smoking, chronic mechanical traumas appeared as significant etiologic factors(p=0.0001).
Conclusions: We believe that field cancerization may become evident in oral and oropharyngealmucosa with multiple steps of molecular changes starting from the first sign of dysplasia with chronic exposureto etiological factors. Chronic trauma cases need particular attention to search for very early signs of cancer.