Clinicopathological study of involvement of the submandibular gland in oral squamous cell carcinoma

Submandibular gland involvement in oral cavity squamous cell carcinoma: a retrospective multicenter study

BACKGROUND

The submandibular gland (SMG) is routinely excised during neck dissection. Given the importance of the SMG in saliva production, it is important to understand its involvement rate by cancer tissue and the feasibility of its preservation.

METHODS

Retrospective data were collected from five academic centers in Europe. The study involved adult patients affected by primary oral cavity carcinoma (OCC) undergoing tumor excision and neck dissection. The main outcome analyzed was the SMG involvement rate. A systematic review and a meta-analysis were also conducted to provide an updated synthesis of the topic.

RESULTS

A total of 642 patients were enrolled. The SMG involvement rate was 12/642 (1.9%; 95% CI 1.0-3.2) when considered per patient, and 12/852 (1.4%; 95% CI 0.6-2.1) when considered per gland. All the glands involved were ipsilateral to the tumor. Statistical analysis showed that predictive factors for gland invasion were: advanced pT status, advanced nodal involvement, presence of extracapsular spread and perivascular invasion. The involvement of level I lymph nodes was associated with gland invasion in 9 out of 12 cases. pN0 cases were correlated with a reduced risk of SMG involvement. The review of the literature and the meta-analysis confirmed the rare involvement of the SMG: on the 4458 patients and 5037 glands analyzed, the involvement rate was 1.8% (99% CI 1.1-2.7) and 1.6% (99% CI 1.0-2.4), respectively.

CONCLUSIONS

The incidence of SMG involvement in primary OCC is rare. Therefore, exploring gland preservation as an option in selected cases would be reasonable. Future prospective studies are needed to investigate the oncological safety and the real impact on quality of life of SMG preservation.

Submandibular Gland in Neck Dissection: Necessary Fatality or Unfortunate Prey?

Excision of submandibular gland is currently victim in all neck dissections. In this study we intend to estimate the prevalence of submandibular gland involvement in squamous cell oral carcinomas and identify the factors associated with it. This is a single institutional, retrospective observational study conducted from 22 to 2018 to 28 February 2020. 317 patients were included for analysis as per study criteria. The prevalence of involvement of submandibular gland was 3.8%. Increased risk of submandibular gland involvement was associated with involvement of level-Ib nodes (Odds ratio: 13.6, 2.9-63.3, 95% CI and p = < 0.001) and presence of extra-nodal extension (Odds ratio: 67, 8.4-532, 95% CI and p = < 0.001) and perineurial invasion (Odds ratio: 5, 1.6-16.8 and p = 0.003). In oral cancers, especially early stage carcinoma of buccal mucosa, submandibular gland preservation may be feasible in absence of extra-nodal extension and level-Ib involvement.

Can Submandibular Gland be Preserved During Neck Disscetion in Oral Cavity Squamous Cell Carcinoma?

Submandibular gland is commonly removed as an integral part of level I neck dissection for oral cavity squamous cell carcinoma. However, it is unclear whether lymph nodes are present within the submandibular gland which may form the basis of lymphatic spread and gland removal. So, this study investigated the incidence of submandibular gland involvement in oral cavity squamous cell carcinoma to determine the possible feasibility of submandibular gland sparing neck dissection. The medical records of 83 patients diagnosed with oral cavity squamous cell carcinoma were reviewed retrospectively to determine frequency of intraglandular lymph nodes in submandibular gland [submandibular gland metastasis] and incidence and mechanism of submandibular gland involvement by oral cavity squamous cell carcinoma. The overall incidence of cervical metastasis was 56.4%, of whom majority had level I metastasis. Submandibular gland involvement via direct invasion from the anatomical proximity of T4a tumors or extra nodal extension from level 1b node was evident in 6 patients. Despite the high incidence of level I metastasis, lymphatic metastases to submandibular gland itself are unlikely based on absence of intraglandular lymph nodes. The results suggest the feasibility of preserving the submandibular gland in early-stage oral cavity carcinoma unless the tumor extends level 1b with extra nodal extension.

[Establishment and application of new techniques for submandibular gland preservation]

The saliva secreted from submandibular gland (SMG) accounts for 60%-65%. It plays an important role in maintaining the human function of swallow, digestion, testing, speech, protection of oral mucosa, and prevention from dental carries. The SMG is frequently resected during the treatment for various kinds of oral and maxillofacial diseases, resulting in xerostomia and decreased quality of life. During the past 15 years, Research Center of Salivary Gland Diseases in Peking University School and Hospital of Stomatology conducted a series of studies on new techniques for preservation of SMG and achieved remarkable results. The clinicopathologic and imaging characteristics of IgG4-related sialadenitis (IgG4-RS) were clarified based on systematic studies. The results of studies on the pathogenesis of IgG4-RS showed that unbalance of inflammatory factors mediated the abnormality of secretion of SMG. IL-4 participates in occurring and development of glandular fibrosis of SMG. Regulation of tumor necrosis factor α (TNF-α) and cleaning of senescent cells might be taken as the targets for treatment of IgG4-RS. The combination of glucocorticoid and steroid-sparing agents showed effective results for treating IgG4-RS, clinical remission was achieved in all the patients, serum IgG4 levels decreased, and salivary gland secretion significantly increased. Sialoendoscopy-assisted sialolithectomy was applied in the treatment of about 1 000 cases with submandibular hilar calculi with a success rate of more than 90%. Transfer of SMG was used for prevention from radiation-induced xerostomia in the patients with head and neck carcinoma. SMG was transferred to the submental region before radiotherapy and was kept away from the ra-diation field. The results of prospective clinical controlled study showed this technique could effectively preserve the function of SMG and prevent from xerostomia. Based on the micro-anatomical study on the blood vessels and ducts of SMG, partial sialoadenectomy was applied for treatment of benign tumors in the SMG. A clinical controlled study confirmed its safety for control of the tumors and its advantage of preservation of SMG function. The studies on the involvement of SMG in oral squamous cell carcinoma (OSCC) provided the anatomical and histopathological basis for preservation of SMG during neck dissection for early cases with OSCC. A innovated surgical modality "four preservations including SMG" was used during the neck dissection for the early cases with OSCC. A prospective randomized clinical controlled study confirmed its safety, feasibility, effectiveness for control of the carcinoma, and advantages of preservation of SMG function.

Rare Metastasis to the Submandibular Gland in Oral Squamous Cell Carcinoma

Purpose

In the current recommendation of neck dissection in oral squamous cell carcinoma (OSCC), the submandibular gland (SMG) should also be removed. This study aimed to investigate the incidence and the patterns of SMG involvement in OSCC patients.

Methods

Patients initially diagnosed with OSCC between January 2018 and October 2020 were included. The distribution of lymph nodes metastasis in level IB was analyzed.

Results

We included 145 patients who underwent primary surgery and neck dissection in this study. All patients had level IB lymph node dissection and simultaneous removal of the SMG. Of these patients, only one patient (0.7%) had involvement in SMG by directly infiltrating from the primary tumor. A total of 18 positive lymph nodes were found in level IB in 16 patients, and no positive lymph nodes were located in the SMG. There were 6 lymph nodes located in the lateral part of the SMG and 12 lymph nodes located in the anterior of the SMG. Patients with tumors located in the buccal mucosa and N3 stage were the independent predictive factors associated with level IB nodal metastasis.

Conclusion

Involvement of SMG in OSCC is quite rare. Preservation of the SMG during neck dissection in selected patients with OSCC seems to be feasible and oncologically safe.

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

INTRODUCTION

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).

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Impact of submandibular gland preservation in neck management of early-stage buccal squamous cell carcinoma on locoregional control and disease-specific survival

Background

The feasibility of submandibular gland (SMG) preservation in oral squamous cell carcinoma (SCC) has occasionally been analyzed, but the differences in survival associated with the presence or absence of SMG preservation remain unknown. We aimed to prospectively evaluate the oncologic results of SMG preservation in cT1-2 N0 buccal SCC.

Methods

This was a prospective, non-randomized cohort study. Patients with surgically treated cT1-2 N0 buccal SCC were prospectively enrolled and divided into two groups based on the management of the SMG. Level 1b lymph nodes were categorized into six groups based on the positional relationship between the lymph node and the SMG. The main study endpoints were locoregional control (LRC) and disease-specific survival (DSS).

Results

A total of 31 of the 137 included patients underwent SMG-sparing neck dissection. Patients with SMG preservation were likely to be young persons. Superior metastasis occurred in 11 patients with a prevalence of 8.0%, followed by an anterior metastasis rate of 5.1%, and no metastases developed deeply or within the SMG. The 5-year LRC rates in the SMG-sparing and SMG-excision groups were 74 and 75%, respectively, and the difference was not significant (p = 0.970). The 5-year DSS rates in the SMG-sparing and SMG-excision groups were 74 and 69%, respectively, and the difference was not significant (p = 0.709).

Conclusions

SMG involvement was rare, and the superior group carried the highest risk for lymph node metastasis. SMG-sparing neck dissection is selectively suggested in cT1-2 N0 buccal SCC patients, and could avoid postoperative asymmetric appearance and dry mouth.

Supplementary information

Supplementary information accompanies this paper at 10.1186/s12885-020-07534-5.

Feasibility of Submandibular Gland Preservation in cT1-2N0 Squamous Cell Carcinoma in the Floor of the Mouth

Purpose: Our goal was to analyze the feasibility of submandibular gland (SMG) preservation in cT1-2N0 floor of the mouth (FOM) squamous cell carcinoma (SCC) patients. Methods: Patients with cT1-2N0 FOM SCC were retrospectively enrolled and divided into two groups according to the management of the SMG. Level 1b tissues were divided into six groups according to their location with respect to the SMG. The Kaplan-Meier method was used to calculate the locoregional control (LRC) and disease-specific survival (DSS) rates. A Cox model was used to determine the independent risk factors. Results: Twenty-nine patients underwent SMG-preserving neck dissection, and lymph node metastasis occurred in the superior group in 3 of the 37 dissections with a prevalence of 8.1% and in the anterior group in 2 of the 37 dissections with a prevalence of 5.4%. In patients without SMG preservation, lymph node metastasis occurred in the superior group in 7 of the 137 dissections with a prevalence of 5.1% and in the anterior group in 6 of the 137 dissections with a prevalence of 4.4%. The only pattern of SMG involvement was invasion by positive lymph nodes. The 5-year LRC rates for patients with SMG preservation and patients with SMG excision were 84 and 73%, respectively, and the difference was not significant (p = 0.239). The 5-year DSS rates for patients with SMG preservation and patients with SMG excision were 88 and 84%, respectively, and the difference was not significant (p = 0.524). Conclusions: In early-stage FOM SCC patients, SMG involvement is rare, the most common metastatic site in level 1b is the superior group, and SMG preservation does not decrease the LRC or DSS rates. Therefore, the findings suggest that there might be high feasibility of SMG-preserving neck dissection in cT1-2N0 FOM SCC.