Distribution and determinants of submandibular gland involvement in oral cavity squamous cell carcinoma

Though the submandibular gland (SMG) is routinely sacrificed for several reasons during neck dissection in patients undergoing curative surgery for oral cavity cancers, it might be an innocent bystander and should be considered for preservation. This study aimed to identify the incidence, different patterns of invasion, and risk factors of SMG involvement in oral cavity squamous cell carcinoma (SCC).

This was a retrospective study of the patients who underwent upfront curative surgery for a biopsy-proven oral cavity SCC. A consistent protocol-based treatment strategy was followed during the study period. Data about clinical profile including demographics, clinical and histology details, and treatment profile were extracted and analysed.

A total of 303 patients underwent unilateral and bilateral neck dissections contributing 79.2% (n = 240) and 20.8% (n = 63) of patients respectively. The common primary sites were buccal mucosa (n = 129, 42.5%), tongue (n = 100, 33.0%) and alveolar gingiva (n = 52, 17.2%). A total of four SMGs showed tumor involvement resulting in a prevalence of 1.09% per neck dissection (n = 366) and 1.32% per patient (n = 303). Of these four cases of SMG involvement, one patient with alveolar cancer had direct tumor invasion while the other three (alveolar cancer - two, tongue cancer - one) patients had neck node metastasis.

The present study confirms a very low incidence of SMG involvement in patients with oral cavity cancer who undergo neck dissection. It is often observed in patients with high neck node burden (≥N2 disease and the presence of extracapsular spread) or direct invasion by the primary tumor.