Takahiro Kamata

Impact of different surgical margin conditions on local recurrence of oral squamous cell carcinoma

The purpose of this study was to analyze the impact of different surgical margin conditions on local recurrence of oral squamous cell carcinoma (SCC) in 148 consecutive patients who underwent planned radical resection of oral SCC. The patients were classified into four categories according to the status of the surgical margin: clear (no SCC within 5mm, n=103), close (SCC within 5mm, n=21), dysplasia (dysplastic epithelium at margin, n=13), and involved (SCC at margin, n=11). Coxs proportional hazard model showed that the status of the surgical margin had a significant impact on local recurrence (p<0.003); hazard ratio was 3.79 (95%CI: 1.17-12.28) with a close and 7.89 (2.38-26.17) with an involved margin. The presence of mucosal dysplasia at the surgical margin was also a significant predictor of local recurrence (hazard ratio: 5.29, 95%CI: 1.31-21.29). Local recurrence was observed only with severe dysplasia, while no recurrence with mild and moderate dysplasia. In the patients with a clear and closed surgical margin, local recurrence was related with T4 tumor and an advanced mode of tumor invasion. The results of this study suggested that the presence of tumor cells at or close to the surgical margin increased the risk of local recurrence. The presence of dysplastic epithelium (especially severe dysplasia) at the mucosal surgical margin has a significant impact on local control. It was also suggested that not simply the width of the free margin but also clinical and histological risk factors should be included in deciding the necessity for adjuvant radiotherapy.

Accuracy of intraoperative tissue staining in delineating deep surgical margins in oral carcinoma surgery

The purpose of this study was to assess the accuracy of this tissue staining assessment of surgical specimens in delineating deep surgical margins in oral cancer surgery. Fifteen patients who underwent surgery for oral carcinoma were included in the study. Once the tumor was resected, a vertical section of the surgical specimen was taken from the central part of the tumor. The section was consecutively stained with 0.4% indigo carmine and 0.5% Congo red, and deep surgical margins were assessed using a digital microscope with a magnification power of 25-175x. The results of tissue staining analysis were compared with the corresponding results of conventional histopathological analysis with HE staining, which is considered the gold standard. The extent of carcinoma invasion could be visualized after the application of tissue staining solutions. Tissue staining analysis was accurate in 12 of the 15 patients (80%) in evaluating the closest deep surgical margin. There was no significant difference in the tumor-margin distance between tissue staining and histopathological assessment in these 12 patients (Wilcoxon signed-ranks test, P>0.63). The results of this study showed that intraoperative tissue staining of surgical specimens permitted visual inspection and assessment of tumor spread to surgical margin, although the method has some limitations. The method had a possible ability in controlling the deep surgical margin.

Usefulness of a commercial enzyme-linked immunosorbent assay kit for Candida mannan antigen for detecting Candida in oral rinse solutions.

OBJECTIVE The aim was to test the performance of a commercial enzyme-linked immunosorbent assay (ELISA) kit for Candida mannan antigen for detecting Candida in oral rinse solutions. STUDY DESIGN Forty-eight oral rinse solutions (38 from patients and 10 from healthy volunteers) were available. Mannan antigen was measured using a commercial sandwich ELISA kit, Unimedi Candida. The result of the mannan assay was compared with the result of conventional detection and identification by culture. RESULTS The result of the mannan assay revealed that 31 of 38 clinical and 3 of 10 healthy volunteer samples were positive for Candida. Using the culture as a gold standard, the overall sensitivity and specificity of the mannan antigen detection were 90.9% and 46.2%, respectively. CONCLUSIONS The results of this study suggested that mannan antigen detection might be a possible and sensitive technique for the detection of oral Candida. The conditions of the ELISA-based assay should be optimized for oral rinse solutions.

Prognostic and staging implications of mandibular canal invasion in lower gingival squamous cell carcinoma

A multi‐institutional study was undertaken to determine whether mandibular canal (MC) invasion and mandibular medullary bone invasion are independent factors in lower gingival squamous cell carcinoma (SCC). A total of 345 patients with lower gingival SCC were retrospectively reviewed. Mandibular bone invasion was categorized into three types; no bone invasion; invasion through cortical bone (medullary); and MC invasion. The overall survival rate and factors affecting local, regional, and distant failures were assessed by Cox proportional hazards regression analysis and Kaplan–Meier estimates. Bone invasion was present in 201 (58%) patients, of whom 107 (31%) had medullary invasion and 94 (27%) had MC invasion. Using the International Union Against Cancer (UICC) staging system and American Joint Committee on Cancer (AJCC) system, 171 (50%) patients were classified as T4a. When the bone invasion criteria were excluded from the UICC/AJCC system definition, 152 T4a tumors were downstaged and reclassified to T1 in 12 (3%), to T2 in 98 (28%), and to T3 in 42 (12%). In Cox multivariate analysis, MC invasion was an independent predictor of overall survival but medullary bone invasion was not. Medullary bone invasion was an independent variable for distant control. The current T staging system has restricted prognostic utility. The authors recommend a modified T staging system, whereby tumors with MC invasion instead of medullary bone invasion are classified as T4a, and tumors are first classified as T1 to T3 based on size and then upstaged by one T classification in the presence of medullary invasion.

Effectiveness of vital staining with iodine solution in reducing local recurrence after resection of dysplastic or malignant oral mucosa

The purpose of this retrospective study was to assess the effect of vital staining with iodine solution in reducing local recurrence after resection of dysplastic or malignant oral mucosa. The historical control group had dysplastic or malignant mucosal lesions resected solely on the evidence of direct inspection and palpation. In the vital staining group tissue was resected only after vital staining with iodine solution. Seven of 25 patients in the conventional group developed recurrent dysplastic or cancerous oral mucosa around the primary site, while no patient among 23 reported recurrence in the vital staining group (p<0.01). Kaplan-Meier assessment showed that the 5-year primary control rate was 100% in the vital staining group and 75% in the conventional group. Although this retrospective study has some limitations, the results suggest that vital staining with iodine may be useful in reducing the incidence of recurrence of dysplastic or cancerous epithelium at a primary site. Further well-controlled study is essential.

Evaluation of the level of progression of extracapsular spread for cervical lymph node metastasis in oral squamous cell carcinoma

Only a few reports on the level of progression of extracapsular spread (ECS) have been published. The aim of this study was to evaluate the efficacy of the level of progression of ECS in identifying those patients with oral squamous cell carcinoma (OSCC) at a high risk of recurrence who would benefit most from the intensification of adjuvant therapy. The level of progression of ECS for cervical lymph node metastasis in OSCC was divided into three types (A-C), and their relationships with patient prognosis were examined. ECS was observed in 87 of 441 patients with OSCC. The recurrence rate in patients with type C, which was defined as macroscopic tumour invasion into perinodal fat or muscle tissue, was high (69.8%), with 13 cases of death due to distant metastasis. The 3-year disease-specific survival rate for patients with type C was 49.0% and these patients also had a significantly poorer prognosis (P<0.01). The results of the multivariate analysis suggested that the prognosis of ECS in OSCC patients was associated with the level of progression of ECS, especially type C (P<0.01). Overall, the results of this study suggest that the level of progression of ECS is a useful prognostic factor in OSCC patients.

Healthy life expectancy of oral squamous cell carcinoma patients aged 75 years and older

OBJECTIVES Healthy life expectancy, an extension of the concept of life expectancy, is a summary measure of population health that takes into account the mortality and morbidity of a population. The aim of the present study was to retrospectively analyze the self-reliance survival times of oral squamous cell carcinoma (OSCC) patients. MATERIALS AND METHODS One hundred and twelve patients aged 75years or older with primary OSCC were included and examined at Shinshu University Hospital. To investigate healthy life expectancy, OSCC patients older than 75years were divided into 3 groups: 75-79, 80-84, and older than 85years. The Kaplan-Meier method was used to estimate the median times of healthy life expectancy. The Log-rank test was used to test significant differences between actual curves. RESULTS The median self-reliance survival times of patients aged 75-79, 80-84, and older than 85years were 5.7, 1.6, and 1.4years, respectively. Most patients with early stage cancers underwent curative treatments and showed a health expectancy of more than 5years. In patients with advanced cancers, health expectancy was poor (less than one year), except among patients aged 75-79years who underwent standard treatments. CONCLUSIONS It seems that in patients with advanced cancers, health expectancy was poor (less than 1year), except among patients aged 75-79years who underwent standard treatments. In elderly patients, healthy life expectancy (self-reliance survival time) may be one of the measures of patient prognosis as well as overall survival times.

Significant prognostic factors affecting treatment outcomes of salivary gland carcinoma: a multicenter retrospective analysis

The purpose of this study was to investigate the prognostic factor in salivary gland carcinoma patients. Clinical and pathological data of 211 consecutive patients who treated with curative intent were analyzed. The overall survival (OS) rate, local control rate, and distant metastasis rate were calculated. To examine a prognostic factor in salivary gland carcinoma patients, a multivariate analysis was performed. The 5-year-OS rate was 84.0%, and 10-year was 69.2%. The 5-year-local control rate was 84.6%, and 10-year was 70.1%. The 5-year-distant metastasis rate was 16.9%, and 10-year was 21.1%. In a multivariate analysis, the OS rate was affected by pN(+), high-grade malignancy, and primary tumor size. The local control was affected by the primary tumor size, high-grade malignancy, and the status of the surgical margin. The primary tumor size and pN(+) were associated with the distant metastasis. The results of this study suggested that pN(+), malignancy grade, primary tumor size, and the margin status might affect the prognosis of salivary gland carcinoma patients. Postoperative radiotherapy and adjuvant chemotherapy were suggested the possibility of contribution to the good prognosis of salivary gland carcinoma patients.

Clinical investigation of 38 cases of oral mucosal melanoma: A multicentre retrospective analysis in Japan

The aim of the present study was to investigate treatment modalities and outcomes in oral mucosal melanoma.

A case of peri-implantitis and osteoradionecrosis arising around dental implants placed before radiation therapy

A little is known about the effect of radiotherapy on the dental implants that have previously been osseointegrated and charged. Here, we reported a case of osteoradionecrosis which arose around dental implants placed before radiation therapy.