Kosuke Sagawa

The threshold of hypothyroidism after radiation therapy for head and neck cancer: a retrospective analysis of 116 cases

The purpose of the present study was to determine the risk factors for developing thyroid disorders based on a dose–volume histograms (DVHs) analysis. Data from a total of 116 consecutive patients undergoing 3D conformal radiation therapy for head and neck cancers was retrospectively evaluated. Radiation therapy was performed between April 2007 and December 2010. There were 108 males and 8 females included in the study. The median follow-up term was 24 months (range, 1–62 months). The thyroid function was evaluated by measuring thyroid-stimulating hormone (TSH) and free thyroxine (FT4) levels. The mean thyroid dose, and the volume of thyroid gland spared from doses ≥10, 20, 30 and 40 Gy (VS10, VS20, VS30 and VS40) were calculated for all patients. The thyroid dose and volume were calculated by the radiotherapy planning system (RTPS). The cumulative incidences of hypothyroidism were 21.1% and 36.4% at one year and two years, respectively, after the end of radiation therapy. In the DVH analyses, the patients who received a mean thyroid dose <30 Gy had a significantly lower incidence of hypothyroidism. The univariate analyses showed that the VS10, VS20, VS30 and VS40 were associated with the risk of hypothyroidism. Hypothyroidism was a relatively common type of late radiation-induced toxicity. A mean thyroid dose of 30 Gy may be a useful threshold for predicting the development of hypothyroidism after radiation therapy for head and neck cancers.

Arterial chemoradiotherapy for carcinomas of the external auditory canal and middle ear

The purpose of this study was to estimate the efficacy of superselective arterial chemoradiotherapy for locally advanced carcinomas of the external auditory canal and middle ear.

Utility of real-time diagnosis using contact endoscopy for oral and lingual diseases.

OBJECTIVE In this study, we prospectively investigated the diagnostic accuracy of CE findings in oral and lingual diseases. METHODS Between January 2004 and December 2009, CE was used to examine 66 patients with oral and lingual diseases at Hyogo College of Medicine Hospital. Blood vessel networks and superficial cell layers in the mucosal epithelium of normal and lesion sites were observed after staining with 1% methylene blue. Endoscopic diagnoses (CE diagnosis) were compared with subsequent definitive diagnoses based on pathological findings. The sensitivity and specificity for CE diagnosis were calculated. RESULTS On CE findings, SCC showed the characteristics of absent and tortuous blood vessels, heterogeneous distribution, and increased nucleus/cytoplasm (N/C) ratio. Leukoplakia showed no atypical cells, abundant cornified layers, or cytoplasm without nuclei. Lesions were pathologically classified into three groups: 46 squamous cell carcinomas (SCC), 10 leukoplakias, and 10 other benign lesions (n=66). In 4 patients with SCC, malignancy was underestimated by CE findings. The overall diagnostic rate of the CE was 93.9% (62/66 patients). The sensitivity and specificity of SCC were 0.913 (42/46 patients) and 1.0 (20/20 patients), respectively. CONCLUSION The usefulness of contact endoscopy (CE) as an in vivo real-time diagnostic instrument that can deliver results prior to pathological confirmation was suggested.

Clinical Study of Surgical Resection for Pulmonary Metastasis of Head and Neck Cancer

Objectives: Although chemotherapy is a common treatment for pulmonary metastasis of head and neck cancer, the prognosis is still poor. This study aimed to examine and evaluate the efficacy of surgical resection for pulmonary metastasis of head and neck cancer. Methods: A total of 15 patients who had undergone 19 resections were examined at our hospital between 2005 and 2012. The patients were followed up for at least 22 months after the surgery, or until their death, with a median period of 36 months. Among the 15 patients, 11 had squamous cell carcinoma, 3 had adenoid cystic carcinoma, and one had malignant melanoma. Results: Of the 19 resections, partial lung resection was performed in 13 cases, lobectomy in 4, and segmentectomy in 2. Video-assisted thoracic surgery was performed in all cases. The mean surgical time, operative blood loss, and length of postoperative hospital stay were 104 minutes, 64 mL, and 7.8 days, respectively. Only 1 patient showed deterioration of the postoperative performance status. For patients with squamous cell carcinoma, the number of pulmonary metastases was 2 or less at the preoperative evaluation. The 3- and 5-year disease-specific survival rates after surgical resection in patients with squamous cell carcinoma were 54.6% and 20.5%, respectively. All patients with adenoid cystic carcinoma and malignant melanoma have survived to date. Conclusions: Lung surgical resection can be considered as one of the effective treatments for pulmonary metastasis of head and neck cancer to improve patient prognosis, with minimal invasion and complications.

Risk Factors for Cervical Lymph Node Metastasis of Tongue Carcinoma to the Unaffected Side

Objectives: Investigate the relationship between cervical lymph node metastasis of tongue carcinoma in unaffected and affected sides and factors related to the primary site. Methods: Between January 2000 and December 2009, 248 patients with primary N0 tongue carcinoma in the unaffected side were treated radically at the Department of Otolaryngology, Osaka Medical Center for Cancer and Cardiovascular Diseases. We evaluated clinical T stage, tumor size, tumor extension (oral floor, anterior part of the tongue, root of the tongue, depth into the tongue) and clinical N stage for risk factors influencing cervical lymph node metastasis to the unaffected side. Results: Fourteen of 248 patients (5.6%) showed cervical node metastasis in the unaffected side. The rate of metastasis to the unaffected side was 17% in patients with primary site extending to the anterior part of the back of the tongue (P < 0.01). The rate was 16% in patients with primary site extending to more than half of the tongue depth (P < 0.05). The rate was 14% in patients with cN+ in the affected side (P < 0.01). Other factors were not associated a significant difference. Conclusions: Extending to the anterior part of the back of the tongue, more than half of the tongue depth and cN+ in the affected side were high risk factors of cervical lymph node metastasis to the unaffected side.

CD44 Expression in Biopsy Specimens of Patients with Nasopharyngeal Carcinoma Is Associated with Prognosis

Objectives: CD44 is a major cancer stem cell marker, and it has been reported to be associated with biological malignancy in several cancers. However, the potential oncogenic role of CD44 and its clinical/prognostic significance in nasopharyngeal carcinoma (NPC) are unclear. In this study, we evaluated the association of CD44, especially its variant isoforms V3 and V6, with prognostic factors in NPC patients. We examined CD44 expression by immunohistochemical analysis of biopsy specimens obtained from 42 NPC patients who underwent treatment. Methods: The subjects were 42 patients (35 men and 7 women; average age, 56.3 years) who received concurrent chemoradiotherapy (CCRT) consisting of chemotherapy (CBDCA or CDGP or DOC) and radiation therapy (60-66 Gy) as an initial treatment. Thereafter, the biopsy specimens from these patients were examined immunohistochemically to study the association between CD44 expression (V3, V6) and prognosis of NPC. Results: High CD44 (V3, V6) expression was significantly correlated with increased clinical incomplete response to CCRT at the primary site (P = 0.008 in V3 and V6 by χ2-test) and poor disease-specific survival (P = 0.0003 in V3 and P = 0.0029 in V6 by log-rank test). However, distant metastasis showed no association with CD44 expression. Conclusions: High expression of CD44 (V3, V6) is associated with poor prognosis in patients with NPC. Evaluation of CD44, especially the variant isoforms V3 and V6, may be useful for predicting tumor response to CCRT and prognosis of patients with NPC.