Tumor size and its Relation to Cervical Lymph Node Metastasis and its Significance as a Prognostic Indicator for Oral Squamous Cell Carcinomas (OSCCs)
Introduction: Oral cancer is the sixth most common cause of cancer-related deaths worldwide. In the Indian scenario, oral cancer is the second most common cancer. The presence of metastatic cervical lymphadenopathy is of particular importance as with every single nodal metastasis, survival of the patient is reduced by one half. Thus, regional metastasis is one of the most important factors in the prognosis and treatment planning of patients with head and neck squamous cell carcinomas. The inaccuracies in clinical examination have been well documented and the diagnostic imaging modalities have been shown to have superior diagnostic accuracy in detecting occult nodal metastasis. Considering the numerous uncertainties regarding the progression, management and outcome of oral cancers, an attempt was made to detect the role of tumor size as a predictive indicator for lymph node metastasis using MR imaging. Materials and Methods: A total number of 27 patients [12 oral canceralveolus, 8 oral cancer-tongue, 7 oral cancer-buccal mucosa] attending as out-patients were included in the study. The patients clinically diagnosed and histopathological proven to have oral squamous cell carcinoma (OSCC) were examined and were evaluated for the tumour size and lymph node status with the help of Magnetic resonance imaging (MRI).Statistical Analysis Used: Values of sensitivity, specificity, positive and negative predictive values and accuracy were calculated. Paired t-test was performed for evaluating size of the tumor and lymph node recorded on clinical and imaging findings. Results: 40% cases were found to be true positive for detecting metastasis using clinical diagnostic criteria whereas 55% cases were found to be true positive for detecting metastasis using imaging criteria. The paired’ test value for the difference in tumor size between clinical and imaging staging was statistically significant (p<0.01). The paired‘t’ test value for the difference in lymph node size between clinical and imaging staging was, also, found to be statistically significant (p<0.01). Overall specificity of 100%, sensitivity of 75%, positive predictive value 72%, negative predictive value 100% and accuracy of 85% were noticed for imaging staging. Conclusion: Detection of tumor size and lymph node metastasis was found to be higher on MRI than that by clinical staging alone. The present study, also, proved that clinical diagnostic criteria alone are less accurate for detecting metastatic lymphadenopathy. MR imaging, thus, can be safely made a recommendation in all head and neck malignancies for pre-operative diagnostic imaging procedures in order to get extremely useful information regarding treatment planning and prognosis in such patients presenting with oral carcinomas.