The impact of lymphovascular invasion on survival in oral carcinoma.

Data was retrospectively analysed on 72 consecutive patients treated primarily with resection and concomitant neck dissection for intraoral carcinomas. Twenty prognostic variables were assessed by univariate analysis to assess their influence on survival. Seven variables were significant at the 5% level. Survival was negatively influenced by six tumour related factors, increasing T stage (P=0.039), increasing N stage (P=0.004), greater than two nodes histologically positive nodal disease (P=0.017), tumour size > 4 cm (P=0.022), residual disease at the primary site (P=0.012), extracapsular nodal spread (P=0.01) and the one treatment related factor analysed, adjuvant radiotherapy (P=0.039). Subsequent multivariate analysis was performed via the cox stepwise regression method to assess the influence on survival of all factors which achieved significance at the 20% level. There were only two variables which made a significant difference (P<0.05) to the multivariate model. The presence of lymphovascular invasion (P=0.015) and histological evidence of mandibular invasion (P=0.047). Lymphovascular invasion appeared in the final model despite not achieving statistical significance at the 5% level on univariate analysis. A final cox survival model was constructed. The relative risk of death for those with cervical metastases (N2 and above) at diagnosis was 3.74 (P=0.005). The addition of lymphovascular invasion to the cox model revealed an increase in the relative risk of death in the presence of lymphovascular invasion of 2.99 (P=0.015). Patients with nodal negative disease and one single node positive provided the baseline risk as there was no significant difference between these two groups. The presence of histological evidence of lymphovascular invasion in oral carcinoma surgical specimens has a significant impact on survival outcome in oral carcinoma patients.