Kojiro Onizawa

Peroxiredoxin I expression in oral cancer: a potential new tumor marker

This study investigates the applicability of the novel antioxidant protein, peroxiredoxin (Prx) I as a marker for tumor status in oral squamous cell carcinoma (SCC). Samples from 53 patients with SCC in the oral cavity were examined by immunohistochemistry. Correlations between the expression level of Prx I and proliferating cell nuclear antigen (PCNA), the clinical features of tumors, and their histopathological classifications were statistically analyzed. Cases exhibiting low Prx I expression level included significantly more with larger tumor mass cases (T-category, P=0.004), positive lymph node metastasis (N-category, P=0.015), advanced stage (P=0.002), and poorly differentiated cells (P=0.020). There was no significant difference between Prx I expression and the other indices.

Factors associated with diagnostic delay of oral squamous cell carcinoma

Shortening the diagnostic delay from the onset of symptoms to the final diagnosis leads to early cancer detection and a reduced incidence of advanced cases. To analyze factors contributing to delays in the diagnosis of oral cancer, information was collected from the medical charts of 152 consecutive patients with oral squamous cell carcinoma, and factors associated with diagnostic delay were examined retrospectively. No characteristic was significantly associated with delay caused by patients. Referral by a non-initial professional, initial visit to a dentist, T1 cancer, and the presence of an ulcerative lesion were significantly associated with delay caused by the initial professionals. Patients with N0 were significantly associated with diagnostic delay caused by the final professional. These results re-emphasize the important role of the initial professional, particularly the dentist, and the diagnostic difficulty posed by ulcerative lesions and small-sized or early-stage oral cancer.

Alteration of temporomandibular joint symptoms after orthognathic surgery: Comparison with healthy volunteers

PURPOSE The purpose was to investigate alterations in temporomandibular joint (TMJ) dysfunction after orthognathic surgery. PATIENTS AND METHODS TMJ symptoms of preoperative patients (n = 30) were compared with those of healthy volunteers (n = 30), and changes in the symptoms were evaluated at 3- and 6-month postoperative intervals. RESULTS There was no significant difference in the incidence of TMJ sounds, deviation of mouth opening, and tenderness of TMJ and masticatory muscles between patients and volunteers. Patients did not report TMJ symptoms significantly more often than the control subjects. At both 3 and 6 months after surgery, half or more of the patients showed no change in TMJ sounds, deviation of mouth opening, or tenderness of TMJ and masticatory muscles. At each evaluation, some patients exhibited improvement of TMJ symptoms or showed changes for the worse. Findings of TMJ sounds were observed to be associated with the postoperative reduction of mandibular mobility. CONCLUSION These results suggest that alterations of TMJ symptoms after orthognathic surgery do not always result from the correction of malocclusion.

Heme oxygenase-1 expression in oral squamous cell carcinoma as involved in lymph node metastasis

Thirty-eight oral squamous cell carcinomas (SCCs) were semi-quantitatively analyzed by immunohistochemical staining, and the relation between heme oxygenase-1 (HO-1) expression and the clinical status were correlated. High immunostaining of HO-1 was detected in lymph node metastasis negative groups (P = 0.0018) and in well-differentiated SCCs (P = 0.0016). There were no significant correlations between heme oxygenase-1 expression and other factors, such as size of the tumor, staging, age and sex. These findings further support the proposition that high heme oxygenase-1 expression in oral SCCs can be useful in identifying patients at low risk of lymph node metastasis.

Fluorescence photography as a diagnostic method for oral cancer

This study was carried out to evaluate the diagnostic utility of autofluorescence photography for oral mucosal lesions. The materials consisted of 15 chemically-induced lesions containing carcinomas in 15 hamsters, and 32 oral lesions in 30 patients. In the animal models, orange fluorescence was detected in all squamous cell carcinomas invading the muscle layer, and the intensity of the fluorescence increased with the progress of the lesions. In the clinical application, orange fluorescence was detected in 14 of 16 malignant tumors and in one of 16 benign lesions. These results suggest that fluorescence photography may be useful for the diagnosis of oral cancer, particularly for squamous cell carcinoma.

Heme oxygenase-1 expression predicts cervical lymph node metastasis of tongue squamous cell carcinomas

Heme oxygenase-1 (HO-1) is known as a stress-inducible protein. The present study was designed to investigate the relationship between HO-1 expression levels and clinical features of tongue cancer by using HO-1 responsiveness to stress as a clinical indicator. One-hundred and twelve biopsy samples from tongue squamous cell carcinomas were analyzed semiquantitatively by immunohistochemistry. Correlations between the expression level of HO-1 and the clinical features of tumors were statistically analyzed. Fifty-four cases with surgical confirmation of lymph node metastasis were examined for the association between cervical lymph node metastasis (pN) and other clinical features, including the HO-1 expression level, using logistic regression. The low HO-1 expression group contained significantly more undifferentiated samples (P=0.04) and pN positive cases (P=0.01) by univariate analysis. The low HO-1 expression group (odds ratio=8.49; 95% confidence interval=1.64-44.09, P=0.01) and an endophytic shape (odds ratio=16.79; 95% confidence interval=1.77-159.53, P=0.01) were significantly associated with an increased risk of developing lymph node metastasis by multivariate analysis. Low HO-1 expression was associated with lymph node metastasis. The expression profile suggests HO-1 could be used clinically as a marker for tumors possessing the potential for lymph node metastasis. This method could prove useful as an adjuvant method to detect lymph node metastasis and may help reduce the number of surgeries by indicating when surgery is unnecessary.

Usefulness of fluorescence photography for diagnosis of oral cancer

This study was carried out to evaluate the validity of fluorescence photography as an adjunctive diagnostic method for oral cancer. Fluorescence photography was performed on 130 oral lesions in 130 patients. Lesions showing red, orange or pink fluorescence on the photographs were defined as positive, while all other lesions were considered negative. Seventy-two (91.1%) of 79 carcinomas and 6 (85.7%) of 7 epithelial dysplasias were judged as positive, whereas two (4.5%) of 44 benign lesions that were not dysplasias showed positive fluorescence. Sixty-nine (94.5%) of 73 squamous cell carcinomas showed positive fluorescence. These results suggest that fluorescence photography is useful as an adjunctive diagnostic method for oral squamous cell carcinoma.

Characterization of autofluorescence in oral squamous cell carcinoma

This study was carried out to evaluate the clinical characteristics of autofluorescence in oral squamous cell carcinoma (SCC) and analyze the fluorescent substances using high-performance liquid chromatography (HPLC). Fifty of 55 oral SCCs (91%) emitted orange or red fluorescence, which was recorded by fluorescence photography. The intensity of the fluorescence significantly correlated with the T and N categories of the cancers, but did not show statistical difference for the types of clinical appearance and primary sites. Protoporphyrin and coproporphyrin were identified as the fluorescent substance in the SCC samples, and the elution patterns on HPLC revealed some porphyrin compounds as specific to oral cancer. These results suggest that the autofluorescence in oral SCC correlates with the progression of lesions, and that fluorescent substances such as protoporphyrin are produced in association with the cancerous tissue.

Real-time tissue elastography for the diagnosis of lymph node metastasis in oral squamous cell carcinoma.

We compared conventional ultrasound (US) B-mode, color Doppler and elastographic assessment of lymph node (LN) stiffness against pathological findings from surgical samples, to determine the most useful factors for identifying LN metastases. Seventy-one LNs in 19 patients with oral squamous cell carcinoma (OSCC) were examined. Using our new system, elastography images were scored from 1-5. The score 1-4 were correlated with the blue area of each LN, which indicated increased stiffness: (1) none; (2) < 50%; (3) 50%; or (4) > 50%. A score 5 indicated central necrosis and did not correlate with the blue area. We found significant differences in minimal diameter, shape index, margin, internal structure, hilus presence or absence, elastography score and percentage of blue area between metastatic and nonmetastatic LNs. Stepwise regression analysis identified elastography score 3-5 as an independent significant LN metastatic factor, suggesting that our scoring system may be useful for accurately diagnosing metastatic LNs.

Analysis of fluorescence in oral squamous cell carcinoma

This study was carried out to examine the spectral properties of the red fluorescence emitted from oral squamous cell carcinoma (SCC). Fluorescent samples obtained from oral cancers induced in hamsters, human oral SCCs, and the medium from cultured oral cancer cell lines were analyzed with a spectrofluorometer with excitation at 404 nm. The spectral profile of the experimentally induced cancers changed with increasing malignancy: peaks at 634 and 672 nm increased and peaks at 520 and 582 nm decreased. A reduction in fluorescence intensity at 582 nm and a rise of intensity at 634 nm were commonly observed in the experimental, clinical, and cell line samples, and the ratio of the fluorescence intensity at 582 nm over that at 634 nm was consistent in all samples. These results suggested that the red fluorescence was emitted by porphyrin, which we believe to be produced by oral SCCs and to accumulate inside or on the surface of cancer tissues in greater amounts with progressing malignancy.