Metastasis to Submandibular Salivary Gland in Oral Carcinoma

Abstract

Objective: To determine the frequency of involvement of the submandibular gland as a metastatic site in squamous cell carcinoma of oral cavity, mechanism of its involvement and factors associated with it. Method: We reviewed the medical and pathologic records of patients who underwent neck dissection (unilateral or bilateral) for oral cavity squamous cell carcinomas (SCC) from January 2009 to July 2017 at the Liaquat National Hospital in Karachi. Cases of histopathologically confirmed SCC of oral cavity and cases of primary tumor in which excision of the submandibular gland (SMG) was done along with neck dissection were included. Those cases with previous surgery for oral cancer and those with previous chemo-radiotherapy were excluded. Results: Median age at presentation was 49.50 years (IQR= 42-58 years). Males were more commonly affected (n=167, 79.5%). The most frequent involved site was buccal mucosa (n=110, 52.4%). Out of 210 neck dissections, SMG was involved by the tumor metastasis in only 8 (3.8%) of the cases. Most common method of involvement was direct invasion by the primary tumor (n=5, 62.5%). Floor of mouth (p<0.001) and level 1 lymph node involvement (p<0.001) were significantly associated with SMG involvement. Conclusion: SMG is the major source of unstimulated saliva. Saliva plays an important role in maintaining oral hygiene and health. Especially in patients of oral cavity SCC who receive post-operative radiotherapy its removal can aggravate xerostomia which can lead to severe discomfort. In this study there was no involvement of SMG in cases in which floor of mouth was not involved and in cases with clinically negative neck. So we concluded that efforts should be made to preserve SMG in these cases to reduce post-operative morbidity associated with its removal.