Clinical characteristics and prognosis of patients with primary squamous cell carcinoma of the retromolar trigone: A SEER-based analysis

BACKGROUND

Primary squamous cell carcinoma of the retromolar trigone (primary SCC RMT) is an uncommon malignant tumor. There is still much to learn about its clinicopathological characteristics and prognosis. In order to better understand the clinicopathological features and predictive survival aspects of primary SCC RMT, this study examined data from the SEER database from 2000 to 2020. Furthermore, in order to forecast the overall survival (OS) and cancer-specific survival (CSS) of patients with primary SCC RMT, we created nomograms.

METHOD

The Surveillance, Epidemiology and End Results (SEER) database was used to retrieve the information on individuals with primary SCC RMT who received a diagnosis between 2000 and 2020. Both univariate and multivariate analyses were conducted using the Cox proportional risk regression model. Using R software, prognostic nomograms were created to forecast the OS and CSS likelihood. The nomograms' prediction abilities were evaluated using the consistency index (C-index), calibration curve, and receiver operating characteristic (ROC) curve.

RESULT

A total of 1717 patients with primary SCC RMT were included, they were randomly assigned to the primary and validation cohorts in a 7:3 ratio using R software. Multivariate Cox regression revealed that age, marital status, regional nodes positive, Summary stage, TNM stage, T stage, N stage, surgery were independent prognostic factors of OS, and age, marital status, regional nodes positive, tumor sizes, Summary stage, N stage, surgery were independent prognostic factors of CSS in the primary cohort. The C-index of the nomogram OS was 0.705 (95 % CI: 0.685-0.725) and the C-index of CSS was 0.734 (95 % CI:0.714-0.754) in the primary cohort. In validation cohort, the C-index of the nomogram OS and CSS were 0.730 (95 % CI: 0.710-0.750) and 0.723 (95 % CI: 0.684-0.762), respectively. The 1-, 3-, and 5-year OS and CSS rates in the primary cohort and validation cohort were approximately in line with the nomogram estimations, in accordance to the calibration curves.

CONCLUSION

We conducted an analysis using the SEER database to investigate the features, survival outcomes, and prognostic parameters of patients with primary SCC RMT. And we developed two prognostic nomograms that can be used by clinicians to forecast the 1-, 3-, and 5-year overall survival and cancer-specific survival of patients with primary SCC RMT.

Retromolar trigone squamous cell carcinoma: A population-based analysis of survival

OBJECTIVES

To evaluate the difference in overall survival (OS) in patients with retromolar trigone squamous cell carcinoma (RMT SCC) treated with surgery alone versus surgery plus postoperative radiotherapy (PORT) versus surgery plus postoperative chemoradiotherapy (POCRT).

MATERIALS AND METHODS

Retrospective cohort study of patients from 1,500 US facilities reporting to the National Cancer Database (NCDB) registry. Participants were adult patients treated with surgery as primary treatment modality for RMT SCC (n = 2,877). Exposures were primary definitive surgery versus surgery + PORT versus surgery + POCRT. Outcomes included OS after diagnosis and treatment of RMT SCC. A multivariate Cox proportional hazards model was constructed to compare survival between the three treatment modalities. Subgroup analysis was performed by T classification and overall staging.

RESULTS

There were 1,415 (50%) patients treated with surgery alone, 870 (30%) patients treated with surgery + PORT, and 572 (20%) treated with surgery + POCRT. Treatment with surgery + PORT was associated with improved OS compared to surgery alone (relative hazard: 1.25, 95% CI: 1.01, 1.54, p = 0.042). Patients treated with surgery + POCRT also had improved OS compared with surgery alone (relative hazard: 1.89, 95% CI 1.45, 2.43, p < 0.001). Patients with T3/4 tumors had improved OS when treated with surgery + PORT (relative hazard 1.39, 95% CI: 1.05, 1.84, p = 0.022) or surgery + POCRT (relative hazard 2.27, 95% CI: 1.66, 3.15, p < 0.001). Patients with T1 or T2 disease had no significant difference in survival in both the surgery + PORT (p = 0.331) and surgery + POCRT treatment groups (p = 0.134). Therefore, there was no difference in OS for patients with stage I or II disease treated with surgery + PORT (p = 0.451), nor with surgery + POCRT (p = 0.853).

CONCLUSION

Treatment with surgery + PORT +/- chemotherapy appears to be associated with significantly improved OS compared to surgery alone for advanced RMT SCCa.

Mucoepidermoid carcinoma of the retromolar trigone in an elderly female: A case report

Tumors of the retromolar trigone area represent 12% of neoplasms of the oral cavity, and of which squamous cell carcinoma represents the main histological type. Mucoepidermoid carcinoma (MEC) of the accessory salivary glands is a rare entity, representing less than 5% of head and neck cancers, and 10% of all salivary gland tumors; its biological characteristics are very diverse, correlated to the histological grade of the tumor. This tumor has an excellent outcome after surgical management, with a prognosis related to the histological grade of the tumor. The authors reported a case of low-grade mucoepidermoid carcinoma, arising in the left retromolar trigon, in an 83-year-old woman who was treated by surgical removal of the tumor with a 1.5 cm border.

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Mucoepidermoid carcinoma (MEC) of the accessory salivary glands is a rare entity.

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Its biological characteristics are very diverse, correlated to the histological grade of the tumor.

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This tumor has an excellent outcome after surgical management; with a prognosis related to the histological grade of the tumor.

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We reported a case of low-grade mucoepidermoid carcinoma, arising in the left retromolar trigon, in an 83-year-old woman, treated by surgical resection.

Reconstruction of buccal mucosa: A minimalist symbiotic approach with local flaps

BACKGROUND

Buccal mucosa defects following resection of premalignant or malignant lesions require adequate reconstruction. Both locoregional and microvascular flaps have been extensively used based on operator and patient factors. This paper focuses on the outcomes of a simplified approach for reconstruction of large buccal mucosa defects with posterior extent using a combination of two loco regional flaps.

METHOD

A combination of buccal fat pad graft and nasolabial flap was used to reconstruct large defects spanning the buccal mucosa extending to the soft palate or retromolar trigone areas. Post operative outcomes were noted in patients who underwent reconstruction using this combination technique.

RESULT

This paper highlights the favourable results and ease of technique with this combination of flaps, i.e complete coverage of large buccal mucosa defects extending to critical areas such as soft palate, retromolar trigone or tonsillar pillars; avoiding sophisticated free flaps. Satisfactory healing with adequate functional and esthetic outcomes were seen.

CONCLUSION

Defects post ablation of buccal mucosa lesions, larger than 5 cm × 5 cm, can be reconstructed using double local flaps. Buccal fat pad and nasolabial flaps heal excellently with nil morbidities and their combination provides a simple and an economical alternative option for reconstructive surgeons.

Treatment outcomes of patients with primary squamous cell carcinoma of the retromolar trigone

OBJECTIVES/HYPOTHESIS

Squamous cell carcinoma of the retromolar trigone (RMT SCC) is a relatively uncommon primary site for oral cavity malignancy. However, given its proximity to the mandible and buccal mucosa, RMT SCC typically exhibits early invasion and generally presents at an advanced stage. Large-sample studies are needed to assess the epidemiology and clinical outcomes of this tumor. Our aim was to describe the determinants of survival in patients with RMT SCC.

STUDY DESIGN

Retrospective cohort study.

METHODS

Retrospective, population-based cohort study of patients in the Surveillance, Epidemiology, and End Results tumor registry who were diagnosed with RMT SCC from 1973 to 2012. Primary endpoints were overall survival (OS) and disease-specific survival (DSS).

RESULTS

A total of 4,022 cases of RMT SCC were identified. The mean age at diagnosis was 65 years. Thirty-nine percent of cases presented with stage IV disease. The median OS by stages I to IV were 73.7, 52.4, 27.5, and 23.4 months, respectively (P < .05). Overall, 34.3% of patients underwent surgery, 23.5% received radiation therapy, and 34.1% had both surgical and radiation therapy. On multivariate analysis, advanced age, greater tumor size, and advanced stage were associated with worse OS and DSS (P < .05), surgery predicted improved OS and DSS (P < .05), and radiation therapy predicted improved OS only (P < .05).

CONCLUSIONS

RMT SCC is an aggressive malignancy that portends a poor prognosis, though early-stage tumors (stages I and II) have significantly improved survival. Any surgical intervention independently predicted higher survival outcomes. There may be a role of dual modality approaches, particularly for larger tumors.

LEVEL OF EVIDENCE

4 Laryngoscope, 128:2740-2744, 2018.

Tumor resection from retromolar trigone, posterolateral maxilla, and anterior mandibular ramus using lower cheek flap approach: a case report and review of literature

A surgical approach involving the retromolar trigone, posterolateral maxilla, and pterygoid region is the most challenging in the field of maxillofacial surgery. The upper cheek flap (Weber-Ferguson incision) with subciliary extension and the maxillary swing approach have been considered as alternatives; however, neither approach provides sufficient exposure of the pterygoid region and the anterior portion of the mandibular ramus. In this report, we describe two cases in which a lower cheek flap approach was used for complete tumor resection in the retromolar trigone and the anterior mandibular ramus. This approach allows full exposure of the posterolateral maxilla and the pterygoid region as well as the retromolar trigone without causing major sensory disturbances to the lower lip. A mental nerve anastomosis after tumor resection was performed in one patient and resulted in approximately 90% sensory recovery in the lower lip. The lower cheek flap approach provides adequate exposure of the posterolateral maxilla, including the pterygoid, retromolar trigone, and mandibular ramus areas. If the mental nerve can be anastomosed during flap approximation, postoperative sensory disturbances to the lower lip can be minimized.

Squamous cell carcinoma of the retromolar trigone: Treatment outcomes

OBJECTIVE

Squamous cell carcinoma (SCC) of the retromolar trigone is uncommon, accounting for 1.4% of all oral cancer cases in Japan. Few studies have examined the optimal treatment for this cancer. The aim of this study was to evaluate the outcome of treatment for primary SCC of the retromolar area.

METHODS

We retrospectively analyzed the outcome and prognosis of 45 patients (38 men, 7 women) with SCC of the retromolar trigone who underwent treatment in our department between July 1992 and March 2011.

RESULTS

Mean age was 62.4 years. Clinical stages were: stage I (n=4, 8.9%); stage II (n=10, 22.2%); stage III (n=5, 11.1%); and stage IVa (n=26, 57.8%). Surgical resection was performed in all patients and 6 patients also received postoperative radiotherapy. Reconstructive surgery using free flaps was performed in 38 patients; postoperative complications occurred in 5 of these patients. The 3-year local control rate was 80%, and the 3-year over all survival rates for stage I, II, III, and IV disease were 100%, 80%, 40%, and 49.2%, respectively. Cause of death was the original disease in 23 cases and other diseases in 2 cases. The most common cause of death from the original disease was cervical lymph node metastasis.

CONCLUSION

The presence of cervical lymph node metastasis was a negative prognostic factor. Marginal mandibulectomy may be selected for patients without distinct bone-marrow infiltration.

A case report of metastasis of malignant mesothelioma to the retromolar trigone

Background

Malignant mesothelioma is a rare and aggressive tumor with a poor prognosis. Distant metastases are very rare, and the oral cavity metastases are exceedingly rare. Only a few cases with metastasis to oral gingiva are reported. To our knowledge, this is the first case report of pleural mesothelioma metastasized to the retromolar trigone.

Case presentation

A 59-year-old male was referred with a painless growth at retromolar trigone area. It had been present for 2 months and had increased in size during this period of time. Past medical history revealed a malignant mesothelioma. Intraoral examination showed a soft, haemorrhagic, ulcerated lesion at the right retromolar trigone area. There was no destruction of the bony architecture. An incisional biopsy was performed under local anaesthesia. Based on the histopathological and immunohistochemical findings, a final diagnosis of metastatic mesothelioma was made. The patient was informed about the possibility of multiple metastases within the body, but he succumbed after 45 days following deterioration of his medical condition.

Conclusions

Biopsy, history of the patient and clinical picture were provided to the clinicians to make an efficient differential diagnosis. Differential diagnosis must be performed with other oral cancers, because the management is totally different.

Basaloid squamous cell carcinoma of the oropharynx: comparison of two cases and review of the literature

We describe a rare case of BSCC in the retromolar trigone with only 3 other cases in the literature and also compare the differences between 2 cases of BSCC in terms of presentation and progression. The first patient had a markedly slower progression with painful retromolar trigone swelling over 4 months without nodal metastases. In contrast, the second patient gave a 2-week history of neck swelling with nodal involvement, indicating extremely rapid progression. Our management was tailored accordingly with the first patient undergoing intraoral excision of tumour and adjuvant radiotherapy while the other had bilateral neck dissection with postoperative chemoradiotherapy. Both patients achieved good outcome and are free from disease.

Diagnostic approach to retromolar trigone cancer by multiplanar computed tomography reconstructions

Neoplasms of retromolar trigone have important peculiarities due to their spatial relationships with the surrounding structures. Tumours that involve this area can extend to nearby muscles; adipose spaces; and other anatomic structures, such as the soft palate, the tonsillar fossa, the parapharyngeal space, and the floor of the mouth. In spite of a relatively quick diagnosis, the real extent of these tumours is typically underestimated at clinical examination. Our purpose was to propose a systematic approach to the use of multiplanar computed tomography reconstructions to evaluate normal retromolar trigone anatomy and the main pathways of spread for tumours that arise in this area. To our knowledge, only few reports exist in literature about this topic and none are about the usefulness of multidetector computed tomography and multiplanar reconstructions.

Transoral robotic surgery for retromolar trigone tumours

The retromolar trigone is a challenging transoral surgical site due to the difficulty of visualization. Our aim is to report a new technique of transoral robotic resection of retromolar trigone tumours. We present three patients with retromolar trigone tumours with pathological diagnosis of squamous cell carcinoma who underwent successful transoral robotic resection. Robotic retromolar trigone resection and concurrent supraomohyoid neck dissections were performed in all patients without any complication. In conclusion, transoral robotic surgery is a safe and feasible technique for resection of malignant retromolar trigone tumours with minimal complications and favourable outcomes.