This retrospective study comprised 176 patients with
squamous cell carcinoma of the oral cavity treated at The Linköping University Hospital over a 19-year period. Clinical parameters, microscopic
malignancy grading (according to Jakobsson et al. and Glanz and Eichhorn),
DNA cytofluorometry, analysis of therapeutic modalities and statistics regarding survival and prognosis are reported. The mean age was 70 years with a male: female ratio of 1.3:1 One hundred and four patients had T1 or T2 tumours and 109 an N0 neck. Cervical
lymph node metastases were more frequent in patients with larger tumours (T3 + T4) than in those with smaller (T1 + T2) (P less than 0.01), in tumours with a high
malignancy grading compared to those with a low (P less than 0.05) and in
DNA non-diploid tumours compared to diploid ones (P less than 0.001). The
aneuploid tumours responded better to preoperative
radiotherapy than did diploid (P less than 0.01) or
polyploid (P less than 0.05) tumours. Eighty-nine per cent of the recurrences occurred within 1 year of initial
therapy. Secondary treatment was successful in 15 of 37 (41%) patients in whom the tumour recurred either at the primary site or in regional lymph nodes, but only in 1 of 8 (12%) with recurrences in both locations. Surgery alone or combined with
radiotherapy resulted in equivalent survival rates for tumours in stages I and II. In advanced stages combined
radiotherapy and surgery gave better survival figures than either modality alone (P less than 0.01; Kaplan-Meier). The presence of
lymph node metastases (P less than 0.001), tumour size (P less than 0.01) and tumour ploidy (P less than 0.005) were the only clinical and histological parameters that significantly influenced survival (Cox regression analysis). Twenty-four patients developed a secondary primary
malignancy; 21 of these were located in the aerodigestive tract.