Cancer of the tongue in Finland : incidence, detection, survival and prognostic factors

Abstract

A population-based study was conducted to determine the trends in incidence and survival of cancer of the mobile tongue in Finland over the past 40 years. Possible changes in patient and tumour characteristics, early detection and prognostic factors of cancer of the mobile tongue were monitored in a geographically defined area of Northern Finland over the past 20 years. There were 1504 new cases with cancer of the mobile tongue in 1953–1994 in Finland and 105 cases in 1974–1994 in Northern Finland. An increasing trend in incidence of cancer of the mobile tongue was observed over the past 20 years both nationwide and in Northern Finland. The stage distribution of the cancer of the mobile tongue remained very much the same throughout the study period. Despite the increasing incidence rate and unchanged stage distribution of the tumours, the 5-year relative survival rate of cancer of the tongue improved from 40% to 58% in the 40-year study period in Finland.

To evaluate the detection of cancer of the tongue, patients’ primary care files were reviewed. It was revealed that the diagnostic skills of the physician/dentist first contacted by the patient had a significant effect on the patient’s prognosis. If the cancer was not detected at the primary visit and no follow-up was scheduled, the delay was often fatally long. The most important factor influencing the referral pattern was the patient’s primary symptom at the initial visit. The more closely the symptom was related to the tongue, the more likely the patient was correctly referred.

To recognise aggressively behaving early stage (Stages I-II) cancers of the tongue, various prognostic factors were analysed. It was observed that an old age (65+years) of the patient, a high malignancy score of the tumour and the absence of p53 predicted poor prognosis in early stage carcinomas. Patients with these qualities may require more aggressive initial therapy.