Prognosis in mouth cancer: tumour factors.

524 patients with histologically proven squamous cell carcinoma of the oral cavity who were previously untreated are studied for prognostic factors. There were various associations between T stage and site; T2 being more common in buccal cancer, T1 in tongue cancer, T4 in floor of mouth tumours and T2 in the roof of the mouth. Floor of mouth cancer tended to be more frequently associated with positive cervical lymph nodes than were other sites (45%). Well-differentiated tumours tended not to be associated with nodal disease (66%). Small tumours tended not to be associated with nodal metastases whereas large ones were. Univariate analysis of observed survival showed that well differentiated tumours had a slightly better survival than poorly-differentiated tumours (a difference of 8%). Survival fell with increasing T stage and with increasing pT stage. Positive resection margins and advanced pT stage in particular had a dismal prognosis. Survival also fell with increasing N stage and with increasing pathological N stage and extranodal rupture adversely affected prognosis. When the data were analysed by Cox's multivariate regression only two factors were found to be significant. These were T stage and N stage. Both were highly significant predictors of survival; survival falling with increasing stage.