Prevalence of submandibular gland involvement in oral carcinoma. A retrospective cohort study.

Background: Refining the overall survival of oral cancer patients has gained traction in the treatment of oral cancer by offering a good quality of life. Restoring the anatomy and function of the glands in the oral cavity has also been an issue of attention. During every neck dissection, the submandibular gland (SMG) is electively removed as a prophylactic measure. The aim of this study was to evaluate the prevalence of SMG involvement in oral cancer patients and to determine the oncological safety of preserving the SMG during neck dissection in patients with oral cancer.

Research design and methods: A total of 215 patients with oral cancer who underwent neck dissection and tumor excision between 2007 and 2018 were included in the study. All data were retrieved from patients treated in a single hospital. Data, including demographics, tumor site, degree of differentiation, involvement of the SMG, Grade of differentiation, and treatment regimens, were collected and evaluated.

Results: Oral cancer was predominant in males, with an increased preponderance amongst the age group of 55 to 65 years. The tongue was the predominant tumor subsite. Only 6.5% of all cases involved the submandibular gland, with the majority of cases involved the floor of the mouth as the primary tumor location, followed by Tongue.

Conclusion: The present study revealed that SMG involvement occurs mostly when the primary tumor site is in close proximity to the gland, such as the floor of the mouth and tongue. However, metastasis to the SMG from other primary sites is very rare. Hence, the decision regarding the excision of the SMG in oral cancer patients should be made during surgery through meticulous frozen section instead of routine excision of the gland during neck dissection. We recommend preserving the SMG in patients with oral malignancies with no compromise in oncological clearance and remaining cautious while dealing with primary subsites, such as the floor of the mouth and tongue, that are in close vicinity to the submandibular gland.