Role of Prophylactic Neck Dissection in Node Negative Carcinoma of Tongue

Prophylactic Neck Dissection in Carcinoma of Tongue

Abstract

Background: To ascertain the role of prophylactic neck dissection in cN0 tongue cancers. To assess the role of tumour thickness as a guide  for the choice type of neck dissection in tongue cancers. Subjects and Methods: A single institutional study by the Department of Surgical Oncology in a teritiary care centre. Biopsy of the tumour site has been done and biopsy proven carcinoma tongue cases have been included in the study. A total of 110 cases of carcinoma tongue were recorded. 50 cases out of the 110 cases were cN0. All the cases were operated by wide local excision of primary tumour and modified radical neck dissection. After the histopathological assessment tumours were divided into two categories, tumours with thickness more than 4mm and those with thickness less than 4mm. Pathological node positivity in both these categories is studied. All the cases were followed up and those with positive nodes were advised post-operative radiotherapy. Results: Among 110 cases studied 50 cases have no clinical nodes at presentation and 60 had cervical lymph node metastases at presentation. Among the 50 cases with no clinical nodes at presentation, histopathology showed that 20 cases (40%) had primary tumour less than 4mm and 30 cases(60%) had primary tumour more than 4mm. 10 of the 20 cases(50%) with tumour thickness less than 4mm had lymph node metastases on pathological assessment and 24 of the 30 cases(80%) with tumour thickness more than 4mm had lymph node metastases on pathological assessment. Among the the category of tumor thickness less than 4mm, 4 cases (20%) had lymph node metastases to level 1, 3 cases (15%) had lymph node metastases to level 2, 3 cases (15%) had lymph node metastases to level 3, 1 case (5%) had lymph node metastases to level 4. Among category of tumour thickness more than 4mm, 10 cases (33.3%) had metastases to level 1, 9 cases (30%) had metastases to level 2, 5 cases(16.6%) had metastases to level 3, 3 cases(10%) had metastases to level 4 and 4 cases (13.33%) had metastases to level 5. Conclusion: The role of neck dissection is the most important step in the management of carcinoma tongue. Prophylactic neck dissection has a definitive role in clinically node negative tongue cancers. Type of neck dissection based on our results showed supraomohyoImid neck dissection would be sufficient for tumours less than 4mm and modified radical neck dissection for tumours more than 4mm thickness. Even most advanced imaging techniques like PET scan and SLNB could not completely derail the need for prophylactic neck dissection in carcinoma tongue.