Treatment of squamous cell carcinoma of the anterior faucial pillar-retromolar trigone

The medial sural artery perforator flap for retromolar trigone reconstruction: A multicenter case series

BACKGROUND

Retromolar trigone (RMT) cancer is a rare malignancy, which develops in a narrow area of the oral cavity. Surgical intervention requires wide excision and appropriate reconstruction usually with a free tissue transfer. Little has been published regarding the ideal microvascular reconstruction, mainly focusing on radial forearm and anterolateral thigh free flap. The medial sural artery perforator flap (MSAP) is not new for head and neck reconstruction but its use for RMT reconstruction has not been previously explored. The purpose of the study is to present a multicentric case series investigating the reliability of MSAP flap for RMT reconstruction.

METHODS

The study is designed as a retrospective case series. All patients diagnosed with RMT cancer and undergone surgical resection and immediate reconstruction with a MSAP flap between February 2016 and March 2020 were identified. Patients' demographics and surgical details were collected. Functional results were evaluated using the Head and Neck Module of the European Organization for Research and Treatment of Cancer at 12 months of follow-up. A total of 34 patients with a mean age of 58 years were included in the study. An average defect size of 31.5 cm2 was observed after RMT tumor resection.

RESULTS

The MSAP flaps' average dimensions were 11 ± 3.1 cm in length and 4.7 ± 1.6 cm in width with a mean thickness of 1.4 ± 0.8 cm. No flap complications were observed in 28 cases; four patients developed an orocutaneous fistula. One patient needed surgical revision for venous congestion while only one case of flap failure was observed. At 12 months of follow-up, 87% of the patient cohort had normal, understandable speech. No patient experienced complete loss of swallowing. Results of the H&N35 module showed a significative postoperative improvement in mouth soreness, mouth opening and social (p < .05*). No patient complained difficulty in motility at the donor site.

CONCLUSIONS

The MSAP flap appears to be appropriate for RMT reconstruction and could be considered the workhorse for small to medium size defect of RTM region. It has a long pedicle of matching caliber and provides adequate tissue volume with minimal donor site morbidity.

Clinico pathological characteristics and survival outcome in oral cavity cancer with masticator space involvement (T4b) - A single institutional experience

INTRODUCTION

Oral cavity cancer with the masticator space involvement is considered as very advanced localised diseas e and staged as T4b in AJCC 8th edition. NCCN guidelines consider this as inoperable. This study intends to compare the different treatment modalities in T4b oral cavity cancer and their impact on survival.

PATIENTS AND METHODS

This is a retrospective study of 150 patients with T4b oral cavity ca, from 2013to 2015 and follow up data till 31 st July 2019 were collected. All patients had biopsy proven SCC and CT evidence of masticator space involvement.

RESULTS

Total of 150 patients were included. 102 patients had received curative treatment and 48 patients had received palliative treatment. In the curative group 84% were treated with surgery and adjuvant treatment and remaining had received RT with or without chemotherapy. 90% patients in the surgically treated group had attained margin negative resection. 4 year OS in the curatively treated group was 58.9% and in the palliative group was 12%. The surgically treated patients in the curative arm had a significant survival advantage over the patients who had received only RT with or without chemotherapy, (63.5% v/s 34%, p = 0.001).

CONCLUSION

Curatively treated oral cavity cancer with masticator space involvement has survival outcome comparable to the published survival data of those without masticator space involvement. Radical intent treatment, preferably surgery should be offered to all patients with masticator space involvement, if negative margin is anticipated from preoperative imaging.

Masseter Flap for Reconstruction of Defects After Excision of Buccal Mucosa Cancers with Intact Mandible

Among the reconstructive options available for buccal mucosa defects with an intact mandible, free flap with microvascular anastomosis is the best option. However, in the developing world, with poor resources, limited in- frastructure, and high patient load, this cannot be offered to all patients. We report on the success of the masseter flap for reconstruction of such defects in carefully selected patients. Despite some known limitations, this flap is easy to learn and carries acceptable complications. The results of this flap may not be comparable to those of microvas- cular reconstructions, but they are better than those from other options such as skin graft, nasolabial flap, submental flap, etc. in terms of surgical time required, no donor site morbidity, and minimal aesthetic deformity.

Guidelines for the Surgical Management of Oral Cancer: Korean Society of Thyroid-Head and Neck Surgery

Korean Society of Thyroid-Head and Neck Surgery appointed a Task Force to provide guidance on the implementation of a surgical treatment of oral cancer. MEDLINE databases were searched for articles on subjects related to “surgical management of oral cancer” published in English. Results were restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies. The quality of evidence was rated with use RoBANS (Risk of Bias Assessment Tool for Nonrandomized Studies) and AMSTAR (A Measurement Tool to Assess the Methodological Quality of Systematic Reviews). Evidence-based recommendations for practice were ranked according to the American College of Physicians grading system. Additional directives are provided as expert opinions and Delphi questionnaire when insufficient evidence existed. The Committee developed 68 evidence-based recommendations in 34 categories intended to assist clinicians and patients and counselors, and health policy-makers. Proper surgical treatment selection for oral cancer, which is directed by patient- and subsite-specific factors, remains the greatest predictor of successful treatment outcomes. These guidelines are intended for use in conjunction with the individual patient’s treatment goals.

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.

Treatment Outcomes of Rare Retromolar Trigone Squamous Cell Carcinoma Using Combined Modalities

Background

Retromolar trigone squamous cell carcinoma is relatively uncommon and due to its complex anatomy has always remained a challenge in terms of loco-regional control and survival. Surgery, radiotherapy, and chemotherapy as combined modalities have been used but high recurrence rates result in poor outcome.

Methods

We have retrospectively evaluated records of 62 patients treated in Head and Neck Oncology unit of Shaukat Khanum Memorial Cancer Hospital and Research Centre (SKMCH and RC), Lahore, Pakistan from 2004 to 2014 who were included based on the criteria of histopathological proven squamous cell carcinoma of retromolar trigone (RMT) treated with radical intent. Diagnostic workup for all patients involved clinical examination, imaging modalities usually magnetic resonance imaging (MRI), computerized tomography (CT), Orthopantomogram (OPG), and chest x-ray (CXR) to evaluate regional and distant metastasis, respectively. Kaplan-Meier survival curves were used to depict survival.

Results

The study was comprised of 36 male and 26 female patients. Treatment modalities used are surgery only (n = 1), radiotherapy alone (n = 13), radiotherapy followed by surgery (n = 10), chemoradiotherapy (n = 16), induction chemotherapy followed by concurrent chemoradiotherapy (n = 19), induction chemotherapy followed by surgery, and radiotherapy (n = 2). Surgical interventions include wide local excisions (n = 6), marginal mandibulectomy (n = 4), and segmental mandibulectomy (n = 4). Surgical margins were clear in 54%, close in 38%, and involved in 8% of patients. AJCC 7th edition showed cT1 8%, cT2 22%, cT3 14%, and cT4 56% while pT1 2%, pT2 3%, and pT4 8%. During follow-up, 18% patients have come up with local recurrence, 22% showed persistent disease while 9% have presented with distant metastasis. The five-year and overall survivals are 38% and 22%, respectively.

Conclusion

Retromolar trigone involvement poses many vital structures at risk of involvement. Late presentation results in involvement of masticator space compromising both mouth opening and surgical outcomes. Surgery and radiotherapy have shown comparable results in disease control. Bone invasion has shown poor outcome in terms of loco-regional control and overall survival.

Retromolar trigone squamous cell carcinoma treated with radiotherapy alone or combined with surgery: a 10-year update

PURPOSE/OBJECTIVES

Treatment outcomes were analyzed for patients who received radiotherapy for squamous cell carcinoma of the retromolar trigone at a single institution.

MATERIALS/METHODS

We reviewed the medical records of 110 patients treated with radiotherapy alone (n=36) or radiotherapy combined with surgical resection of the primary tumor (n=74) between June 1966 and October 2013. The median follow-up was 4.5years for all patients and 11.8years for living patients (range, 1.3-23.5years).

RESULTS

The 5-year local-regional control rates after definitive radiotherapy versus surgery and radiotherapy for stages I-III were 52% and 89% and for stage IV they were 46% and 58%, respectively. The 5-year cause-specific survival rates after definitive radiotherapy compared with surgery and radiotherapy for stages I-III were 57% and 82% and for stage IV they were 45% and 43%, respectively. Multivariate analyses revealed that the likelihood of cure was better with surgery and radiotherapy compared with radiotherapy alone (p=0.041).

CONCLUSION

Patients treated with surgery and radiotherapy had a better chance of cure than those treated with radiotherapy alone. Complications of treatment were common in both groups but more common in patients who underwent surgery.

A comparative study of fused FDG PET/MRI, PET/CT, MRI, and CT imaging for assessing surrounding tissue invasion of advanced buccal squamous cell carcinoma

PURPOSE

This study aimed to evaluate the diagnostic value of fused fluorodeoxyglucose positron emission tomography and magnetic resonance imaging (PET/MRI) compared with PET/computed tomography (CT), MRI, and CT in assessing surrounding tissue invasion of advanced buccal squamous cell carcinoma (BSCC).

MATERIALS AND METHODS

PET/CT and MRI were performed in 17 consecutive patients with suspected masticator space invasion of BSCC from CT images. Attenuation-corrected PET and head and neck MRI datasets were registered. For pathologic correlation, 4 regions of interest were examined, including the maxilla, mandible, pterygoid, and masseter muscle. The tumor maximal diameter, measured by different imaging modalities, was correlated with pathology results.

RESULTS

All PET/MRI fusions were verified as well matched using specific anatomic criteria. For pathology results, 1 patient had inflammation only, 1 had spindle cell cancer, and 15 had squamous cell cancer. Of 64 regions of interest, 20 (31.3%) harbored tumor invasion. The likelihood ratio was highest in fused PET/MRI (42.56) compared with PET/CT (25.02), MRI (22.94), and CT (8.6; all P < 0.05). The sensitivity and specificity of fused PET/MRI were also highest among the 4 modalities (90.0%/90.9%, 80.0%/84.1%, 80.0%/79.5%, and 55.0%/81.8%, respectively). The level of confidence was higher in fused PET/MRI or MRI than in PET/CT or CT (85.9%, 85.9%, 70.3%, 73.4%, respectively). The maximal lesion size was 3.0 to 6.0 cm in the pathology specimen. Regression analysis showed better agreement between fused PET/MRI and pathology results.

CONCLUSIONS

Fused PET/MRI is more reliable for focal invasion assessment and tumor size delineation in advanced BSCC compared with PET/CT, MRI, and CT. PET/CT has the lowest confidence level, which may limit its use in the clinical setting.

Population-based study of treatment outcomes in squamous cell carcinoma of the retromolar trigone

BACKGROUND

Carcinoma of the retromolar trigone is relatively uncommon. High rates of local recurrence account for a relatively poor prognosis.

STUDY DESIGN

A population-based historical cohort of 76 cases with biopsy-proven squamous cell carcinoma of the retromolar trigone were studied as a case series. Kaplan-Meier survival curves and log rank test were used for statistical analysis.

RESULTS

The mean age was 67.2 years. Fifty-six patients were male, 45% had T1 or T2 tumors, and 61% were staged as N0. Treatment included radiotherapy in 35%, surgery alone in 26%, surgery and radiotherapy in 23%, and 16% received palliative treatment. The absolute and disease-specific survivals at 5 years were 51.4% and 67.7%, respectively. In patients treated with surgery, the resection margin status predicted the overall 5-year survival (P = .027), with 75% of patients with negative margins surviving 5 years versus a survival of 0% of patients with involved margins.

CONCLUSIONS

Squamous cell carcinoma of the retromolar trigone has a poor survival rate for early-stage disease. Adequate surgical margins can improve survival.

Squamous cell carcinomas arising from different types of oral epithelia differ in their tumor and patient characteristics and survival

A hypothesis that OSCCs originating from different types of oral epithelia may have different patient and tumor characteristics was evaluated in this retrospective analysis of 188 patients with primary OSCC treated at Turku University Central Hospital, Turku, Finland in 1988-1997. The tumors were categorized according to the type of oral epithelium from which they have originated: (1) specialized epithelium (dorsal tongue) (2) keratinized (masticatory) epithelium, (3) non-keratinized (lining) epithelium, and (4) tongue epithelium (epithelium on the lateral border of the tongue). The relevant clinical data, including age, sex, social status, and risk behavior of the patients and clinical presentation, histopathological grading, and treatment of the tumors, as well as the follow-up information, were collected from the patient charts of the hospital. In general, tumor and patient characteristics of OSCCs and survival rates were found to be in line with those of recent analyses reported from other industrialized countries. However, OSCCs in young patients (4.8%) seemed to be clinically at a lower stage and histologically more highly differentiated than those of the other patients. Eight out of 9 (89%) OSCCs in the young patients were located on the lateral tongue. The 5-year recurrence-free rates of the patients according to the epithelial origin of the tumors were as follows: masticatory epithelium 42%, lining epithelium 57%, and epithelium of the lateral border of the tongue 61%. In conclusion, the tumors originating from different types of oral epithelia may have distinct properties with regard to their clinical behavior and responsiveness to the different treatment modalities. It would seem to be meaningful to investigate the molecular characteristics of the different types of oral epithelium in order to elucidate possible differences in their susceptibility to malignant transformation.

T4b oral cavity cancer below the mandibular notch is resectable with a favorable outcome

According to the AJCC 2002 staging system, squamous cell carcinoma of the oral cavity (OSCC) with T4b is unresectable. Herein, we report on our surgical outcome for T4b OSCC. All patients were enrolled before 2002. From January 1996 to December 2000, 45 consecutive untreated T4b OSCC patients were included. According to the trans-axial plane of the mandibular notch on CT/MRI, seven were supra-notch T4b and 38 were infra-notch T4b tumors. Significantly higher 5-year loco-regional control and survivals were observed in patients with infra-notch T4b than with supra-notch T4b. In the infra-notch group, pN0-1 patients had a significantly higher 5-year loco-regional control and survivals than pN2 patients. Nerve invasion was the sole significant adverse factor for loco-regional control and survivals in the infra-notch T4b group with pN0-1. Our retrospective study demonstrated that OSCC patients of infra-notch T4b with pN0-1 and no nerve invasion might have a favorable surgical outcome.

Surgical outcome of T4a and resected T4b oral cavity cancer

BACKGROUND

The American Joint Committee on Cancer (AJCC) 2002 staging system (AJCC 2002) suggested that squamous cell carcinoma of the oral cavity (OSCC) with T4b is unresectable. The current retrospective results show that selected T4b patients were resectable with favorable outcomes.

METHODS

From January 1996 to December 2000, 103 consecutive untreated T4 OSCC patients (reclassified by AJCC 2002) without carotid artery encasement and skull base extension were eligible for radical treatment. All received head-and-neck magnetic resonance imaging (MRI) and/or computed tomography (CT) scans before operation. The surgical principles were safety margins of > or =1 cm for primary tumors, modified/radical neck dissections for clinical lymph node-positive disease, and supraomohyoid neck dissection for lymph node-negative disease. In all, 95.1% of patients (98 of 103 patients) underwent free-flap reconstructions. Adjuvant radiotherapy or concomitant chemoradiotherapy was administered to those with pathological T4 (AJCC 1997), cervical lymph node metastasis, or close margins (< or =4 mm). Survivals were calculated according to the method of Kaplan and Meier.

RESULTS

In all, 58 patients were classified as having T4a disease and 45 were classified as having T4b disease. No statistical difference was observed in the 5-year local control, neck control, disease-free survival, and overall survival rates between the T4a and T4b groups. In multivariate analyses, pathologic lymph node status (pN0-1 vs. pN2) was found to be the sole independent predictor for T4b for local control (P = .012), disease-free survival (P = .005), and overall survival (P = .008).

CONCLUSIONS

Selected T4b OSCC patients were found to be resectable with outcomes that were comparable to those of T4a OSCC patients and may benefit from radical surgery, free-flap reconstruction, and adjuvant therapy. A pathologic lymph node status of > or =2 was found to be the sole independent predictor for T4b disease in local control and survival.

Treatment of Squamous Cell Carcinoma of the Retromolar Trigone

OBJECTIVES

Retromolar trigone (RMT) squamous cell carcinoma is uncommon but notorious for poor prognosis. We reviewed our experience in the management of RMT cancer to determine survival rates and to identify prognostic factors.

METHODS

Fifty patients with RMT squamous cell carcinoma were treated with surgery and/or radiation or chemoradiation therapy between July 1993 and June 2004 at Chang Gung Memorial Hospital, Taiwan. Patients were followed up for 3 to 106 months (mean, 36 months). There were 6 stage I, 13 stage II, 4 stage II, and 27 stage N patients.

RESULTS

The 5-year actuarial survival rate for stage I to N and all stages were 100%, 74.1%, 75%, 43.6%, and 60.6%, respectively. Seventeen (34%) patients had maxilla bone (11 [22%]) or mandible bone (9 [18%]) invasion. Eleven (22%) patients had masticator space involvement. Cervical metastasis rate was 26%. Multivariate analysis revealed that masticator space involvement, neck recurrence, and cervical metastasis were poor prognosticators of survival by order. The maxilla bone was more apt to be involved by RMT cancer than the mandible. Patients with masticator space involvement had a 5-year actuarial survival rate of 22.5% and the mean survival time was only 37.8 months.

CONCLUSIONS

RMT squamous cell carcinomas are aggressive tumors. The maxilla is more apt to be involved than the mandible. Deep infiltration of the masticator space and invasion of the maxilla and mandible worsen the prognosis.

Superiorly based and island masseter muscle flaps for repairing oropharyngeal defects

INTRODUCTION

Tumours of the posterior part of the mouth and/or the oropharynx are often diagnosed at advanced stages. Reconstruction in this region has advanced considerably during the last three decades. Although microsurgery has offered major progress and has obviously improved the patients' outcome, the use of local and regional flaps generally remains an ideal solution for reconstruction.

MATERIAL AND METHODS

Between January 1994 and December 2001, the defects resulting from resection in 22 out of 38 patients with retromolar and/or anterior faucial pillar squamous cell carcinomas treated at this institution, were repaired by one of two types of masseter muscle flaps. The first type is the superiorly based or cross-over masseter muscle flap, and the second type the island muscle flap (being a modification of the first type).

RESULTS

The superiorly based masseter muscle flap was used in 12 patients and the island masseter muscle flap in 10. Both techniques offer a quick and reliable method for repairing oropharyngeal defects in oncologically "safe" cases. Neither require elaborate technique or aftercare.

CONCLUSION

The island masseter muscle flap has an advantage over the superiorly based masseteric flap, as it is more flexible, pliable for larger defects, and causes no postoperative trismus.

Retromolar trigone squamous cell carcinoma treated with radiotherapy alone or combined with surgery

BACKGROUND

Treatment outcomes were analyzed for retromolar trigone squamous cell carcinoma.

METHODS

Between June 1966 and August 2003, 99 patients were treated with radiotherapy alone (35 patients) or radiotherapy combined with surgery (64 patients). Followup ranged from 0.2 to 23.8 years (median, 3.3 yrs). All living patients had followup for at least 1 year.

RESULTS

The 5-year local-regional control rates after definitive radiotherapy versus surgery and radiotherapy were as follows: Stages I-III, 51% and 87%; Stage IV, 42% and 62%; and overall, 48% and 71%, respectively. The 5-year cause-specific survival rates after definitive radiotherapy compared with surgery and radiotherapy were as follows: Stages I-III, 56% and 83%; Stage IV, 50% and 61%; and overall, 52% and 69%, respectively. Multivariate analyses revealed that the likelihood of cure was better with surgery and radiotherapy compared with definitive radiotherapy.

CONCLUSIONS

The likelihood of cure after treatment for retromolar trigone squamous cell carcinoma was influenced by the extent of disease and treatment. Patients treated with surgery and radiotherapy had a better outcome than those treated with radiotherapy alone.