Prognostic value of a mandibular canal staging system for primary lesions in patients with lower gingival squamous cell carcinoma: a multicenter, retrospective study.

BACKGROUND: The Union for International Cancer Control and American Joint Committee on Cancer tumor staging system is used globally for treatment planning. As it may be insufficient for tumor staging of lower gingival carcinomas, we proposed the mandibular canal tumor staging system. In this study, we aimed to compare the two systems for such tumor staging and to identify prognostic markers. METHODS: This multicenter, retrospective study included patients with lower gingival squamous cell carcinoma who underwent radical surgery during 2001-2018. We compared survival rates (Kaplan-Meier estimator) and patient stratification according to the two systems. RESULTS: The proposed system yielded more balanced patient stratification than the existing system. Progression in the tumor grade according to the proposed system was associated with a poorer prognosis. The 5-year overall and disease-specific survival rates for the entire cohort were 74.9% and 81.8%, respectively. Independent factors affecting overall survival were tumor stage according to the proposed system, excision margins, and number of positive nodes, whereas those affecting disease-specific survival were excision margins and number of positive nodes. CONCLUSIONS: Subsite-specific tumor classification should be used for patients with oral cancer, and our results suggest that mandibular canal tumor classification may be effective for patients with lower gingival carcinoma.

Comparison of the 8th edition of TNM staging of oral cancer with the 7th edition and its prognostic significance using clinical depth of invasion and extranodal extension.

OBJECTIVES: The 8th edition of the International Union Against Cancer Control/American Joint Committee on Cancer Staging System introduced depth of invasion (DOI) and extranodal extension (ENE) into the staging of oral cavity cancer. We evaluated the prognostic ability of this new staging system compared with the 7th edition using clinical DOI (cDOI) and clinical ENE (cENE). MATERIALS AND METHODS: We retrospectively reviewed and restaged 2,118 patients with oral squamous cell carcinoma treated between 2001 and 2018 using cDOI and cENE. Overall and disease-specific survival were used as endpoints to compare the prognostic outcomes of the 7th and 8th editions using Harrell's concordance index (C-index). RESULTS: In total, 305 (14.4 %) cases were upstaged in the T category, 85 (4.0 %) cases were upstaged in the N category, and 280 (13.2 %) cases were upstaged in the overall TNM stage. The introduction of the cDOI increased the C-index and hazard ratio (HR) for each T category. The introduction of cENE increased the N3b category of 85 cases, bringing the total to 94 cases, thereby widening the differences between each N category. In the 8th edition, the C-index and HR for overall TNM stage increased, and the discrimination between stage groups improved. CONCLUSIONS: The 8th edition of the TNM clinical staging system using cDOI and cENE predominantly identified patients with a high mortality rate, thus improving the ability to discriminate and prognosticate oral cancer.

Multicenter retrospective study of the prognosis and the effect of postoperative adjuvant therapy in Japanese oral squamous cell carcinoma patients with close margin.

BACKGROUND: The purpose of this retrospective study was to investigate the prognosis of patients with oral cavity cancer with positive margin (PM) or close margin (CM) divided into pN- and pN+ groups. METHODS: The evaluated endpoints were local control and disease-specific survival (DSS) rates. RESULTS: Higher T classification, lymphovascular space invasion (LVSI), and older age were significant risk factors for DSS in the pN- groups. On the other hand, extranodal extension, multiple lymph node metastases, and LVSI were significant risk factors for DSS in the pN+ groups. Among the CM pN+ patients, no significant differences in the 3-year DSS were observed between the only surgery (51.9%) and adjuvant groups (53.2%). CONCLUSIONS: Higher T classification and LVSI are high-risk features more than PM or CM in the pN- groups for DSS. However, further prospective studies are needed to demonstrate the usefulness of adjuvant treatment in patients with PM or CM.

The Impact of Pretreatment Low Body Mass Index on Cause-Specific Mortality in Patients with Squamous Cell Carcinoma of the Oral Cavity.

The association between the pretreatment body mass index (BMI) and oral squamous cell carcinoma (SCC) outcomes is controversial. We aimed to examine the association between BMI and cause-specific mortality due to cancer of the oral cavity and patterns of failure that correlate with increased mortality. We enrolled 2,023 East Asian patients in this multicenter cohort study. We used the cumulative incidence competing risks method and the Fine-Gray model to analyze factors associated with cause-specific mortality, local recurrence, regional metastasis, and distant metastasis as first events. The median follow-up period was 62 mo. The 5-year cause-specific mortality for patients with underweight was 25.7%, which was significantly higher than that for patients with normal weight (12.7%, P < 0.0001). The multivariate model revealed that underweight was an independent risk factor for cause-specific mortality and regional metastasis (P < 0.05). Moreover, patients with underweight displayed a 51% and 55% increased risk of cause-specific mortality and regional metastasis, respectively, compared with their normal weight counterparts. Local recurrence was not associated with the BMI categories; however, the incidence of distant metastasis inversely decreased with BMI value. In summary, being underweight at diagnosis should be considered a high-risk mortality factor for oral SCC.

A Multicenter Study on the Effect of Margin Distance on Survival and Local Control in Stage 1-2 Squamous Cell Carcinoma of the Tongue.

BACKGROUND: Pathological close margins are considered a significant factor for local recurrence in patients with oral cancer. However, the oral cavity has complicated anatomical features, and the appropriate margin distance for each site is unknown. This multicenter, retrospective study aimed to determine the appropriate resection margin for early tongue cancer and investigate the need for additional treatment for close margins and stump dysplasia. PATIENTS AND METHODS: In total, 564 patients from ten hospitals were enrolled in this study. Sex, age, performance status, T stage, tumor length diameter, depth of invasion, elective neck dissection, iodine staining, horizontal margin distance, vertical margin distance, pathological differentiation, invasion pattern, lymphatic invasion, perineural invasion, dysplasia in the resection edge, additional treatment for close margins, local recurrence, neck metastasis, distant metastasis, and outcomes were investigated. RESULTS: Receiver operating characteristic analysis for local recurrence revealed cut-off values of 3.3 mm for horizontal distance and 3.1 mm for vertical distance. Patients with close horizontal or vertical margins showed significantly higher local recurrence rates, but these were not associated with overall or disease-specific survival. Furthermore, there was no effect of additional treatment in patients with dysplasia at the surgical margin. CONCLUSION: For early tongue cancer, a horizontal margin of 3.3 mm was defined as a close margin. Close margins were significantly correlated with local recurrence but did not affect survival. In the future, we would like to examine the concept of "quality margins," including the surrounding anatomical features.

Short ramus reconstruction for hemi-mandibulectomy defect: Case reports.

Reconstruction of the mandible following hemimandibulectomy is difficult and complex. The appropriate approach to condylar reconstruction remains controversial. In this report, the authors propose the concept of "short ramus reconstruction" after hemimandibulectomy. In this technique, a neocondyle is constructed around the base of the condyle to avoid trismus and ankylosis. Four patients underwent short condylar reconstruction using fibula free flaps. Post-surgery, no patient developed trismus or ankylosis. Centric occlusion, good masticatory function, and favourable aesthetic outcomes were achieved in all cases. "Short ramus reconstruction" is a simple and convenient method to reconstruct the mandible following hemimandibulectomy.

Breast Cancer in a Pectoralis Major Myocutaneous Flap Used for the Reconstruction of Tongue Cancer: A Case Report.

Breast cancers are the most common cancers in women. However, breast cancer occurring in a pectoralis major myocutaneous flap is extremely rare. This article describes a case of breast cancer occurring in such a flap used for reconstruction of the tongue in a 72-year-old woman. Follow-up computed tomogram depicted a slowly growing mass in the flap. Thirty-nine months postoperatively, a fine-needle aspiration biopsy specimen taken from the lesion suggested glandular carcinoma. The patient was diagnosed with breast cancer in the neck area of the flap and tumor excision was performed. Histologic examination of the excised tumor showed tumor cells arranged in cords, with tubular and cribriform carcinomas near the pectoral muscle with adipose tissue. The cytoplasm was abundant and eosinophilic. Thus, the patient was diagnosed with invasive ductal carcinoma in the pectoralis major flap. Sequential radiotherapy was performed to the neck with a total radiation dose of 50 Gy. Furthermore, the patient received oral anastrozole 1 mg daily as systemic adjuvant therapy for the receptor-positive breast malignancy. One year after surgery, the patient was alive with no evidence of disease. Including this case, only 2 cases of breast cancer in a pectoralis major myocutaneous flap used for reconstruction in the head and neck region have been reported.

Basaloid squamous cell carcinoma of the mandible: report of two cases.

Basaloid squamous cell carcinoma is a rare aggressive malignancy that is a distinct variant of squamous cell carcinoma. This report presents 2 cases of basaloid squamous cell carcinoma in the gingiva. Case 1 is a 55-year-old Japanese man who presented with a painful, red, and irregular mass on the left mandibular gingiva. Case 2 is a 65-year-old Japanese man who presented with a painless mass on the right mandibular gingiva. Both tumors were diagnosed histopathologically as basaloid squamous cell carcinoma. In case 1, the patient underwent wide resection of the gingival tumor with a partial mandibulectomy and ipsilateral functional neck dissection. The mandible was reconstructed with a titanium plate and forearm flap. In case 2, the patient underwent wide resection of the gingival tumor after local irradiation (60 Gy). At the time of writing, both patients remained in good health and free of disease.