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.

Oral melanoma: a multicenter study of 69 patients from Japan.

OBJECTIVES: The purpose of this multicenter retrospective study was to investigate the demographic characteristics and treatment outcomes of patients with mucosal malignant melanoma (MM) of the oral cavity. MATERIALS AND METHODS: This was a multicenter study involving 8 Japanese universities. The medical records of 69 patients who were diagnosed with primary oral MM between January 2000 and December 2020 were retrospectively analyzed. Overall survival (OS) and prognostic factors for OS were analyzed statistically. RESULTS: There were 40 (58.0%) males and 29 (42.0%) females, and their mean (range) age was 69.8 ± 14.6 (22-96) years old. The most common primary site was the palate (30 patients, 43.5%). Stage IVA was the most common disease stage (36 patients, 52.2%). Radical therapy was performed in 55 patients (79.7%). The 2-year and 5-year OS rates of the 69 patients were 64.6% and 42.5%, respectively. The 2-year and 5-year OS rates of the stage III patients were 85.9% and 72.5%, respectively, and those of the stage IVA patients were 56.3% and 26.0%, respectively. The 1-year OS rate of the stage IVB/IVC patients was 26.7%. The 2-year and 5-year OS rates of the radical therapy group were 74.1% and 50.5%, respectively, whereas the 2-year OS rate of the non-radical therapy group was 26.0%. An advanced T classification was the only identified prognostic factor for OS (hazard ratio: 6.312, 95% confidence interval: 1.133-38.522, p < 0.05). CONCLUSIONS: Early detection and radical treatment are essential for improving the prognosis of oral MM patients. CLINICAL RELEVANCE: Early detection and adequate radical therapy leads to the better prognosis of oral MM patients.