Seiichi Yoshimoto

SOX10 is a novel marker of acinus and intercalated duct differentiation in salivary gland tumors: a clue to the histogenesis for tumor diagnosis.

Salivary gland tumors are relatively rare and morphologically diverse and heterogeneous tumors; therefore, histogenesis-based tumor markers are sorely needed to aid in diagnosing and determining the cell type of origin. SRY-related HMG-box 10 (SOX10) protein is a transcription factor known to be crucial in the specification of the neural crest and maintenance of Schwann cells and melanocytes. In addition, positive expression has also been implicated in the major salivary gland. Here, we examined SOX10 expression in various salivary gland tumors to correlate this expression with myoepithelial markers. Overall, 76 malignant and 14 benign tumors were examined. SOX10 expression clearly delineated two distinct subtypes of human salivary gland tumors; acinic cell carcinomas, adenoid cystic carcinomas, epithelial-myoepithelial carcinomas, myoepithelial carcinomas, and pleomorphic adenomas, including the pleomorphic adenoma component of carcinoma, were SOX10 positive, while salivary duct carcinomas, mucoepidermoid carcinomas, an oncocytic carcinoma, Oncocytomas, and Warthin tumors were SOX10 negative. Also, SOX10 was expressed in solid-type or non-specific morphology salivary gland tumors, but was not expressed in poorly differentiated squamous cell carcinomas. In normal human salivary gland tissue, SOX10 expression was specific to the nuclei of acini and both luminal and abluminal cells of intercalated ducts but not in other sites. Moreover, the murine model suggested that SOX10 continued to be expressed from the developmental stage to adulthood in the acinar and both luminal and abluminal intercalated ducts in the major salivary gland. Thus, SOX10 is a novel marker for diagnosing and understanding the histogenesis of salivary gland tumors.

CIC-rearranged Sarcomas: A Study of 20 Cases and Comparisons With Ewing Sarcomas.

The CIC gene rearrangement exists in a subset of small round cell sarcomas. As the nosologic relationship of these sarcomas to Ewing sarcomas remains undetermined, we examined 20 CIC-rearranged sarcomas to compare their clinicopathologic features with those of Ewing sarcomas. The CIC-rearranged sarcomas were from a group of 14 men and 6 women with a median age of 24.5 years. The primary tumor sites included the limbs, trunk wall, internal trunk, lung, cerebrum, and pharynx. A comparison of the demographic and clinical characteristics of the 20 patients with CIC-rearranged sarcomas with those of the 53 near-consecutive patients with EWSR1-rarranged Ewing sarcomas showed that there were no differences with respect to their ages and sexes. Although none of the CIC-rearranged sarcomas arose in the bone, 40% of the Ewing sarcomas primarily affected the skeleton. The overall survival of patients with Ewing sarcomas was significantly better than that for patients with CIC-rearranged sarcomas. A histologic comparison of the CIC-rearranged sarcomas with 20 EWSR1-rearranged Ewing sarcomas showed significantly higher degrees of lobulation, nuclear pleomorphism, the prominence of the nucleoli, spindle cell elements, and myxoid changes in the CIC-rearranged sarcomas. Distinguishing immunohistochemical features included heterogenous CD99 reactivity, nuclear WT1 expression, and calretinin expression in the CIC-rearranged sarcomas and NKX2.2 expression in the Ewing sarcomas. CIC-rearranged sarcomas are distinct from Ewing sarcomas clinically, morphologically, and immunohistochemically, and they should be considered a separate entity rather than being grouped within the same family of tumors.The CIC gene rearrangement exists in a subset of small round cell sarcomas. As the nosologic relationship of these sarcomas to Ewing sarcomas remains undetermined, we examined 20 CIC-rearranged sarcomas to compare their clinicopathologic features with those of Ewing sarcomas. The CIC-rearranged sarcomas were from a group of 14 men and 6 women with a median age of 24.5 years. The primary tumor sites included the limbs, trunk wall, internal trunk, lung, cerebrum, and pharynx. A comparison of the demographic and clinical characteristics of the 20 patients with CIC-rearranged sarcomas with those of the 53 near-consecutive patients with EWSR1-rarranged Ewing sarcomas showed that there were no differences with respect to their ages and sexes. Although none of the CIC-rearranged sarcomas arose in the bone, 40% of the Ewing sarcomas primarily affected the skeleton. The overall survival of patients with Ewing sarcomas was significantly better than that for patients with CIC-rearranged sarcomas. A histologic comparison of the CIC-rearranged sarcomas with 20 EWSR1-rearranged Ewing sarcomas showed significantly higher degrees of lobulation, nuclear pleomorphism, the prominence of the nucleoli, spindle cell elements, and myxoid changes in the CIC-rearranged sarcomas. Distinguishing immunohistochemical features included heterogenous CD99 reactivity, nuclear WT1 expression, and calretinin expression in the CIC-rearranged sarcomas and NKX2.2 expression in the Ewing sarcomas. CIC-rearranged sarcomas are distinct from Ewing sarcomas clinically, morphologically, and immunohistochemically, and they should be considered a separate entity rather than being grouped within the same family of tumors.

Sentinel node biopsy for oral and laryngopharyngeal squamous cell carcinoma: a retrospective study of 177 patients in Japan.

OBJECTIVE Sentinel node (SN) biopsy in the head and neck region has not been widely used in Japan, except at a few facilities. However, almost all these facilities perform preoperative localization and intraoperative diagnosis by frozen section analysis of SN to select patients who must undergo neck dissection in a one-stage procedure. The objective of this study was to determine the actual status of SN biopsy at those facilities in Japan that have actively conducted this procedure, and to elucidate the usefulness and drawbacks of this technique in head and neck cancer. METHODS We retrospectively reviewed 177 patients who had undergone SN biopsy at 7 facilities. The underlying pathology was laryngeal or hypopharyngeal cancer in 20 patients from one hospital, while the remaining 157 patients had oral cancer. Preoperative localization of SN was determined using conventional lymphoscintigraphy with or without single photon emission computed tomography with CT (SPECT-CT). Intraoperative localization and diagnosis of SN were performed by gamma probe and frozen section analysis. RESULTS Conventional lymphoscintigraphy detected a mean of 2.6 SNs per patient in 137 patients with oral cancer, compared to 2.7 in 71 patients using SPECT-CT and 2.9 in 154 patients using the gamma probe. No significant differences were apparent between techniques. Forty of the 520 SNs (7.7%; 33 in oral cancer and 7 in laryngeal or hypopharyngeal cancer) were pathologically positive in the final diagnosis. Of these, 3 were not processed for frozen sectioning and were diagnosed only with hematoxylin and eosin staining. Among the others, 32 (86.5%) were diagnosed intraoperatively as showing metastasis. In terms of the false-negative rate, 144 patients were determined by SN biopsy to have no positive SNs. Of these, 2 patients had non-SN metastases found in their dissected neck and 8 patients without neck dissection showed late nodal recurrence. The false-negative rate was thus 6.9%. CONCLUSION Frozen section analysis, particularly multislice sectioning, offers a relatively reliable intraoperative diagnostic method. We were able to perform immediate neck dissection based on the results of multislice sectioning as a single-stage procedure.

Stem cell self-renewal factors Bmi1 and HMGA2 in head and neck squamous cell carcinoma: clues for diagnosis

Head and neck squamous cell carcinoma (HNSCC) includes both morphological and functional cellular heterogeneity, as would be expected if it arose from dysregulated stem or progenitor cells as opposed to the simple clonal expansion of a mutated cell; however, stemness molecule expression levels and distribution in HNSCC remain unclear. To clarify this, stemness molecule expressions were determined in HNSCC, as well as their properties and prognosis. Two proto-oncogenic chromatin regulators, Bmi-1 and high-mobility-group A2 (Hmga2), were identified in 12 pair cases of HNSCC tumor regions by comparison with their non-cancerous background tissues using cDNA microarray. Both Bmi-1 and Hmga2 are known to promote stem cell self-renewal by negatively regulating the expressions of Ink4a and Arf tumor suppressors. Despite similar targets, Bmi-1 protein was expressed in an early cancerous region and HMGA2 protein was expressed in a region showing more progression. Similarly, Bmi1 expression had no significance with regard to overall survival (P=0.67), whereas HMGA2 expression was associated with decreased overall survival (P=0.05). Quantitative real-time reverse transcription polymerase chain reaction analyses also correlated with protein levels. These findings suggest that Bmi-1 is an early detection marker to distinguish cancerous from non-cancerous regions, whereas HMGA2 is presumed to be a tumor prognosis marker. Among our HNSCC analyses, these stemness molecules expressed fewer primitive rare cells in the tumor than all other cells in the tumor. HNSCC cells with high expression of stemness molecules partly behave like stem cells.

Copy number increase of ACTN4 is a prognostic indicator in salivary gland carcinoma

Copy number increase (CNI) of ACTN4 has been associated with poor prognosis and metastatic phenotypes in various human carcinomas. To identify a novel prognostic factor for salivary gland carcinoma, we investigated the copy number of ACTN4. We evaluated DNA copy number of ACTN4 in 58 patients with salivary gland carcinoma by using fluorescent in situ hybridization (FISH). CNI of ACTN4 was recognized in 14 of 58 patients (24.1%) with salivary gland carcinoma. The cases with CNI of ACTN4 were closely associated with histological grade (P = 0.047) and vascular invasion (P = 0.033). The patients with CNI of ACTN4 had a significantly worse prognosis than the patients with normal copy number of ACTN4 (P = 0.0005 log‐rank test). Univariate analysis by the Cox proportional hazards model showed that histological grade, vascular invasion, and CNI of ACTN4 were independent risk factors for cancer death. Vascular invasion (hazard ratio [HR]: 7.46; 95% confidence interval [CI]: 1.98–28.06) and CNI of ACTN4 (HR: 3.23; 95% CI: 1.08–9.68) remained as risk factors for cancer death in multivariate analysis. Thus, CNI of ACTN4 is a novel indicator for an unfavorable outcome in patients with salivary gland carcinoma.

Analysis of 59 cases with free flap thrombosis after reconstructive surgery for head and neck cancer

OBJECTIVE There have been few reports addressing methods of dealing with free flap thrombosis after reconstructive surgery for head and neck cancer. The present study, through a detailed analysis of the subsequent course of patients who developed postoperative flap thrombosis, aims to clarify possible methods of salvage surgery in the event of vascular occlusion despite rigorous postoperative follow-up. METHODS We analyzed 59 cases of postoperative thrombosis in 1031 patients who underwent free flap transfer and considered the most appropriate salvage surgery in the event of total flap necrosis. RESULTS The flap salvage rate through vascular reanastomosis was highest for radial forearm flaps, with salvage of jejunal flaps being problematic if postoperative thrombosis occurred. For cases of postoperative thrombosis among patients who underwent reconstruction using a jejunal flap, the period of hospitalization was significantly extended for those patients in whom a second jejunal flap grafting was impossible. For cases of postoperative thrombosis among patients who underwent reconstruction using a radial forearm flap (FA), rectus abdominis flap (RA), or anterior lateral thigh flap (ALT), no significant difference was observed between those undergoing re-grafting with a free flap and those with a pedicled flap. CONCLUSION We concluded that, among patients who undergo reconstruction using a jejunal flap, thrombosis should be discovered at an early stage to enable another jejunal flap re-grafting. For patients who undergo reconstruction using a FA, RA, or ALT, if thrombosis can be discovered at an early stage, there is a possibility of salvaging the flap by means of vascular reanastomosis. If it should prove impossible to salvage the flap, however, primary suture of the defect or reconstruction with a pedicled flap may also be considered.

Primary Tumor-Secreted Lymphangiogenic Factors Induce Pre-Metastatic Lymphvascular Niche Formation at Sentinel Lymph Nodes in Oral Squamous Cell Carcinoma

Objectives The objectives of this study were to evaluate the formation of lymphvascular niches in lymph nodes of patients with oral squamous cell carcinoma (OSCC), and investigate the roles of lymphangiogenic and angiogenic factors, such as vascular endothelial growth factor (VEGF)-A, VEGF-C, and VEGF-D, expressed in the primary tumors. Materials and Methods Forty-four patients with previously untreated clinically late T2 or T3 OSCC of cN0 were evaluated for primary tumors and 166 sentinel lymph nodes (SLNs). Primary tumors were immunohistochemically analyzed for expressions of VEGFs. Densities of lymphatic vessels (LVDpodoplanin) and high endothelial venules (HEVD) in the SLNs were also calculated using antibodies for each marker, podoplanin and MECA-79, respectively. Results In 25 patients, all lymph nodes were metastasis-negative, whereas, in 19 patients, metastasis was positive for at least one lymph node (either at SLN, non-SLN, or nodal recurrence). From the analyses of 140 SLNs without metastasis, LVDpodoplanin in 50 SLNs of metastasis-positive cases was significantly higher than that in 90 SLNs of metastasis-negative cases (p = 0.0025). HEVD was not associated with lymph node metastasis. The patients with VEGF-A-High or VEGF-D-High tumors had significantly higher LVDpodoplanin than patients with their Low counterparts (p = 0.0233 and p = 0.0209, respectively). In cases with lymph node metastasis, the VEGF-D-expression score was significantly higher than in those without lymph node metastasis (p = 0.0006). Conclusions These results suggest that lymph node lymphangiogenesis occurs before metastasis in OSCC. VEGF-A and VEGF-D play critical roles in this process. VEGF-D is a potential predictive marker of positive lymph node metastasis in cN0 patients.

Factors involved in free flap thrombosis after reconstructive surgery for head and neck cancer.

OBJECTIVE Reconstructive surgery in which a free flap is used following extended resection for head and neck cancer has been popular for more than a quarter of a century. However, postoperative total flap necrosis has not been completely resolved, and few studies have analyzed the specific risk factors for this complication. METHODS Over a three-year period from 2005 to 2007, 388 flaps were used for reconstructive surgery on 384 patients at Department of Head and Neck of the Cancer Institute Hospital of Japanese Foundation for Cancer Research, and the results for 22 flaps with thrombosis were analyzed. RESULTS The only statistically significant risk factor for free flap thrombosis was the history of radical concurrent chemoradiotherapy. CONCLUSIONS It will be necessary to keep this observation in mind when performing salvage surgery following chemoradiotherapy, which is expected to be performed more often in the future.

Treatment results for 84 patients with base of tongue cancer.

Conclusions. For T2 tumors, surgery was indicated if functional preservation was possible. For T3/T4 tumors, the rate of primary disease control was not high and surgery frequently involved total laryngectomy. Points that surgeons must heed when performing such surgery were delineated. Objectives. Because tumors originating from the base of the tongue are rare, few large-scale studies of such tumors have been performed. We reviewed treatments and outcomes at our department to establish effective future therapeutic plans. Patients and methods. From 1971 to 2000, 84 patients with previously untreated and resectable squamous cell carcinoma of the base of the tongue were treated at the Head and Neck Department of the Cancer Institute Hospital, Tokyo. Treatment selection and results were investigated. Results. The main treatment options were radiotherapy for primary lesions ≤ T2 and surgery for primary lesions ≥ T3. Overall disease-specific 5-year cumulative survival rate was 59.8%, but there was no significant difference in survival rate at each stage between the two treatments. Among patients who died of the primary disease, the area that was most difficult to control was the superior margin of the lateral wall of the oropharynx (n=7). The incidence of contralateral or retropharyngeal lymph node metastasis was low if tumors neither crossed the midline nor infiltrated the lateral wall. While total laryngectomy was performed on 48 patients, the larynx was operatively preserved in 5 T3 patients and one T4 patient.

Carcinoid tumor of the larynx: clinical analysis of 33 cases in Japan

Conclusion. In regard to the treatment of carcinoid tumor of the larynx, irradiation is not effective and tumor excision with a minimum surgical margin is associated with a high risk of local recurrence. Lymph node metastases to the neck are associated with worsening of the prognosis. To improve the survival rate, primary resection with a sufficient surgical margin (e.g. partial laryngectomy) and (elective) neck dissection is recommended, even for patients with early stage carcinoid tumors of the larynx. Objective. The objective of this study was to clarify the prognostic factors, modalities of treatment for the primary lesions, and importance of neck dissection in the treatment of carcinoid tumors of the larynx. Patients and methods. The data of 33 cases of carcinoid of the larynx reported from Japan (including 2 of our cases) were analyzed. Results. The distributions of the T and N classifications of the lesions were as follows T1, 50.0%; T2, 32.2%; T3, 14.3%; T4, 3.6%; N0, 57.1%; N1, 17.9%; N2, 25.0%; and N3, 0%. Fifteen patients underwent radiation therapy, of whom five underwent curative radiotherapy. While complete remission (CR) was maintained in one of these patients (T1N0), the remaining four patients developed recurrence. Five patients underwent preoperative radiation therapy. The response to the treatment was rated as no change in four patients and as progressive disease in the remaining one patient. Among the patients with N0 disease, seven patients (43.8%) developed lymph node metastases in the neck postoperatively. Distant metastases were the most frequent cause of death in the patients. The 3-year, 5-year, and 10-year survival rates of the patients were 58.5%, 36.5%, and 12.2%, respectively. Significant differences were recognized in the survival rates between patients with and without neck lymph node involvement at the first treatment (p=0.008), and between patients with and without postoperative lymph node recurrence in the neck (p=0.037).