Ken-ichi Notani

Management of mandibular osteoradionecrosis corresponding to the severity of osteoradionecrosis and the method of radiotherapy.

To demonstrate appropriate treatment methods for mandibular osteoradionecrosis (ORN) by evaluating previous results.

Assessment of cervical lymph node metastases using FDG-PET in patients with head and neck cancer

ObjectiveTo evaluate the diagnostic accuracy of fluorodeoxyglucose positron emission tomography (FDG-PET) relative to computed tomography (CT) for detecting metastatic cervical lymph nodes in patients with squamous cell carcinoma of the head and neck (HNSCC), and to ascertain the factors that affect this accuracy.MethodsA total of 1076 lymph nodes obtained from 35 neck dissections in 26 HNSCC patients who preoperatively underwent both FDG-PET and CT were retrospectively analyzed. For pathological metastatic lymph nodes, the lymph node size (short-axis diameter), the ratio of intranodal tumor deposits, and the size of intranodal tumor deposits (maximum diameter of metastatic foci in each lymph node) were histologically recorded.ResultsForty-six lymph nodes from 23 neck sides were pathologically diagnosed metastases. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of FDG-PET evaluated individually per neck side were 74%, 92%, 80%, 94%, and 65%, respectively, whereas those of CT were 78%, 58%, 71%, 78%, and 58%, respectively. FDG-PET detected 100% of metastatic lymph nodes ≥10 mm, intranodal tumor deposits ≥9 mm, and intranodal tumor deposits with a ratio >75%, whereas no nodes or tumor deposits smaller than 5 mm were detected. The spatial resolution limitations of FDG-PET were responsible for 16 of 20 (80%) false-negative PET results in lymph nodes.ConclusionsFDG-PET is a useful tool for preoperative evaluation of the neck because it accurately detects metastatic lymph nodes ≥10 mm and has fewer false-positive cases than CT. The high specificity of FDG-PET for lymph node metastases may play an important role in avoiding unnecessary neck dissection.

Specific p53 mutations predict poor prognosis in oral squamous cell carcinoma

In this study, we focused on p53 mutations in specific regions, including DNA-binding surface regions, to clarify the correlation between mutations within the specific regions of p53 and clinical outcomes of patients with oral cancers. We analyzed p53 mutations in 121 fresh primary oral squamous cell carcinomas (SCCs) by polymerase chain reaction-single-strand conformation polymorphism or a yeast functional assay. p53 mutations were detected in 51/121 (42%) cases. Mutation of p53 was not associated with any clinicopathological parameters; however, tumors containing specific p53 mutations, e.g. DNA-binding surface regions (L2, L3 and the LSH motif) and conserved regions (II-V), had significantly poorer prognoses than tumors with mutations outside of those regions. Moreover, locoregional failure, lymph node metastasis and the occurrence of subsequent distant metastasis were also significantly associated with mutations within DNA-binding surface regions. These data indicate that specific mutations of p53 could be important prognostic factors in oral SCCs.

Flow cytometric analysis of nuclear DNA content in oral leukoplakia: relation to clinicopathologic findings

DNA ploidy of 50 biopsy specimens of oral leukoplakia was investigated by flow cytometry, and the results were compared with the clinicopathologic appearances. The aneuploidy rate of the leukoplakias was 17/50 (34%), and the mean DNA index (DI) of the aneuploid lesions was 1.22, with a range from 0.70 to 1.84. The incidence of the aneuploidy was significantly (P < 0.01) higher in nonhomogeneous leukoplakias (11/18) than in homogeneous lesions (6/32). The aneuploidy rate of the severely dysplastic leukoplakias (11/17) was significantly higher than those of the mildly dysplastic (4/22; P < 0.01) and the nondysplastic (2/11; P < 0.02) lesions. A significant (P < 0.01) difference in the aneuploidy rate was also observed between tongue (12/23) and gingival (2/18) leukoplakias.

Clinical value of genetically diagnosed lymph node micrometastasis for patients with oral squamous cell carcinoma.

The purpose of this study was to investigate the incidence and clinical significance of genetically diagnosed lymph node micrometastasis for patients with oral squamous cell carcinoma (SCC).

Flow cytometric analysis of nuclear DNA content in tongue squamous cell carcinoma: relation to cervical lymph node metastasis

The relationship between DNA ploidy and the incidence of cervical lymph node metastasis in 36 patients with tongue squamous cell carcinoma (SCC) was investigated. The aneuploidy rate of tongue carcinomas was 15/36 (42%), and the mean DNA index (DI) was 1.23, with a range from 0.87 to 3.54. Histologically identified cervical lymph node metastasis was observed in 11 cases, and the incidence of the cervical lymph node metastasis was significantly (P < 0.02) higher in the aneuploid cases (8/15) than in the diploid cases (3/21). Recurrence of the primary lesions was seen in nine cases 0.3-2.5 years after the initial treatment. No obvious difference in the incidence of the recurrence was noted, however, between the diploid (5/21) and the aneuploid (4/15) cases. These results indicate a significant relationship between aneuploidy and incidence of the regional lymph node metastasis, in contrast to the absence of a positive relationship between aneuploidy and recurrence of tongue SCC.

DNA analysis of oral leukoplakia by flow cytometry

DNA ploidy of 19 oral leukoplakias with and without epithelial dysplasia was investigated and the results were compared with 11 normal gingival biopsies, 14 oral benign tumours and 50 oral squamous cell carcinomas. The results suggest a possible relationship between DNA aneuploidy and oral leukoplakias or squamous cell carcinomas, as 32% of the oral leukoplakias and 48% of the oral squamous cell carcinomas were aneuploid although all the normal gingival biopsies and the benign oral tumours examined were diploid. No significant relationship was observed, however, between DNA ploidy and epithelial dysplasia in the leukoplakias.

Serum p53 antibodies as a prognostic indicator in oral squamous cell carcinoma

The purpose of the present study was to investigate the clinical usefulness of the detection of serum p53 antibodies (p53 Abs) in patients with oral squamous cell carcinoma (SCC). Preoperative values of p53 Abs were measured by enzyme-linked immunosorbent assay in 113 patients with primary oral SCC and seropositive patients were reevaluated postoperatively. The positivity rate of p53 Abs was 16%, and the 5-year survival rate of patients positive for p53 Abs was significantly lower than that of patients negative for p53 Abs (56.2% vs. 80.7%; P = 0.018). The preoperative presence of p53 Abs was found to be an independent prognostic factor in a multivariate analysis (P = 0.028, hazards ratio = 3.34), and its positivity was significantly related to secondary cervical lymph node metastases (P = 0.029). Six of nine patients who remained seropositive for p53 Abs through the disease course and the one with seropositive reversion from temporary negative status developed treatment failure. Therefore, the detection of p53 Abs in the serum of patients with SCC may be a useful prognostic marker.

Osseous choristoma of the tongue

Osseous choristoma of the tongue is a relatively rare lesion with 53 cases previously published in the literature. In this article, two additional cases are described; one in a 53-year-old woman located close to the foramen caecum, and the other in a 18-year-old woman on the left of midline and just anterior to the circumvallate papillae that was observed over a 13-year period.

Migration of gutta-percha point from a root canal into the ethmoid sinus.

There have been reports on the migration of teeth or implants into the maxillary sinus, but we know of no report on the migration of a gutta-percha point that had been used to fill a root canal into the ethmoid sinus. We report such a case which presumably migrated through the maxillary sinus.