Impact of dysplasia at resection margin on oncologic outcome after curative resection of oral tongue squamous cell carcinoma: significance of high-grade dysplastic resection margin.

BACKGROUND: This study aimed to compare the oncologic outcomes among negative, close, positive, and dysplasia resection margins (RMs) with oral tongue squamous cell carcinoma (OSCC) and to investigate the impact of dysplastic RMs. METHODS: The 565 patients were retrospectively analyzed and divided into four groups according to RM. Dysplasia was classified into mild, moderate, and severe subgroups. RESULTS: RMs consisted of negative (62.1%), close (27.1%), positive (2.1%), and dysplastic (8.7%). In multivariate analysis, advanced T/N stages and positive RM were significant risk factors for overall survival, while dysplasia at the RM was not a significant risk factor for locoregional recurrence or overall survival. In subgroup analysis of patients with dysplastic margin, RM with severe dysplasia showed higher recurrence than mild and moderate dysplasia. CONCLUSIONS: Dysplastic RM was not a risk factor for recurrence and survival. Severe dysplasia RM should be carefully observed due to higher recurrence compared to other dysplasia RMs.

Detection of Cancer Recurrence Using Systemic Inflammatory Markers and Machine Learning after Concurrent Chemoradiotherapy for Head and Neck Cancers.

Pretreatment values of the neutrophil-to-lymphocyte ratio (NLR) and the platelet-to-lymphocyte ratio (PLR) are well-established prognosticators in various cancers, including head and neck cancers. However, there are no studies on whether temporal changes in the NLR and PLR values after treatment are related to the development of recurrence. Therefore, in this study, we aimed to develop a deep neural network (DNN) model to discern cancer recurrence from temporal NLR and PLR values during follow-up after concurrent chemoradiotherapy (CCRT) and to evaluate the model's performance compared with conventional machine learning (ML) models. Along with conventional ML models such as logistic regression (LR), random forest (RF), and gradient boosting (GB), the DNN model to discern recurrences was trained using a dataset of 778 consecutive patients with primary head and neck cancers who received CCRT. There were 16 input features used, including 12 laboratory values related to the NLR and the PLR. Along with the original training dataset (N = 778), data were augmented to split the training dataset (N = 900). The model performance was measured using ROC-AUC and PR-AUC values. External validation was performed using a dataset of 173 patients from an unrelated external institution. The ROC-AUC and PR-AUC values of the DNN model were 0.828 ± 0.032 and 0.663 ± 0.069, respectively, in the original training dataset, which were higher than the ROC-AUC and PR-AUC values of the LR, RF, and GB models in the original training dataset. With the recursive feature elimination (RFE) algorithm, five input features were selected. The ROC-AUC and PR-AUC values of the DNN-RFE model were higher than those of the original DNN model (0.883 ± 0.027 and 0.778 ± 0.042, respectively). The ROC-AUC and PR-AUC values of the DNN-RFE model trained with a split dataset were 0.889 ± 0.032 and 0.771 ± 0.044, respectively. In the external validation, the ROC-AUC values of the DNN-RFE model trained with the original dataset and the same model trained with the split dataset were 0.710 and 0.784, respectively. The DNN model with feature selection using the RFE algorithm showed the best performance among the ML models to discern a recurrence after CCRT in patients with head and neck cancers. Data augmentation by splitting training data was helpful for model performance. The performance of the DNN-RFE model was also validated with an external dataset.

Can Definitive Radiation Therapy Substitute Surgical Resection in Locally Advanced T3 or T4 Sinonasal Squamous Cell Carcinoma?

PURPOSE: This study aimed to compare oncologic outcomes between definitive radiation therapy (RT) and upfront surgical resection in patients with sinonasal squamous cell carcinoma (SCC). METHODS AND MATERIALS: Between 2008 and 2021, 155 patients with T1-4b, N0-3 sinonasal SCC were analyzed. The 3-year overall survival (OS), local progression-free survival (LPFS), and overall progression-free survival (PFS) were evaluated using the Kaplan Meier method and compared using a log-rank test. A pattern of regional neck lymph node (LN) failure and treatment-related toxicity profiles were investigated. RESULTS: A total of 63 and 92 patients underwent upfront RT (RT group) and surgical resection (Surgery group), respectively. The RT group included significantly more patients with T3-4 disease than the Surgery group (90.5% vs 39.1%, P < .001). The rates of 3-year OS, LPFS, and PFS in the RT and Surgery groups were 68.6% versus 81.7% (P = .073), 62.3% versus 73.8% (P = .187), and 47.4% versus 66.1% (P = .005), respectively. However, the corresponding rates in patients with T3-4 disease were 65.1% versus 64.8% (P = .794), 57.4% versus 56.8% (P = .351), and 43.2% versus 46.5% (P = .638), respectively, demonstrating no statistically significant differences between the 2 treatment modalities. Among the 133 N0 patients, regional neck LN progression was observed in 17 patients, and the most common sites of regional neck LN failure were ipsilateral levels Ib (9 patients) and II (7 patients). The 3-year neck node recurrence-free rate in cT1-3N0 patients was 93.5%, while that in cT4N0 patients was 81.1% (P = .025). CONCLUSIONS: Upfront RT may be considered in selected patients with locally advanced sinonasal SCC, as we have demonstrated similar oncologic outcomes to those of surgery. Prophylactic neck treatment in T4 disease requires further investigation to evaluate its efficacy.

Outcomes of Salvage Therapy for Oropharyngeal Cancer Recurrence Following Upfront Radiation Therapy and Prognostic Factors.

PURPOSE: This study aimed to investigate the oncologic outcomes and prognostic factors of salvage treatments in patients with recurrent oropharyngeal squamous cell carcinoma (OPSCC) after radiotherapy (RT)-based treatment. MATERIALS AND METHODS: A cancer registry was used to retrieve the records of 337 patients treated with definitive RT or concurrent chemoradiotherapy (CRT) from 2008 to 2018 at a single institution. The poor-responder group (PRG) was defined as patients with residual or recurrent disease after primary treatment, and the oncologic outcomes for each salvage treatment method were analyzed. In addition, prognostic indicators of recurrence-free survival (RFS) and overall survival (OS) were identified in patients who underwent salvage treatment. RESULTS: After initial (C)RT, the PRG comprised 71 of the 337 patients (21.1%): 18 patients had residual disease, and 53 had recurrence after primary treatment (mean time to recurrence 19.5 months). Of these, 63 patients received salvage treatment (surgery 57.2%, re-(C)RT 23.8%, and chemotherapy 19.0%), and the salvage success rate was 47.6% at the last follow-up. The overall 2-year OS for salvage treatments was 56.4% (60.8% for the salvage surgery group and 46.2% for the salvage re-(C)RT). Salvage surgery patients with negative resection margins had better oncologic outcomes than those with close/positive resection margins. Using multivariate analyses, locoregional recurrence and residual disease after primary surgery were associated with poor outcome after salvage treatment. In Kaplan-Meier analyses, p16 status was significantly associated with OS in the initial treatment setting but not in the salvage setting. CONCLUSION: In recurrent OPSCC after RT-based treatment, successful salvage was achieved in 56.4% patients who had undergone salvage surgery and radiation treatment. Salvage treatment methods should be selected carefully, given recurrence site as a prognostic factor for RFS.

Improved Early Detection Models of Pharyngocutaneous Fistula after Total Laryngectomy.

Early detection of pharyngocutaneous fistula (PCF) after total laryngectomy (TL) could prevent severe complications such as major vessel rupture. We aimed to develop prediction models for detecting PCF in the early postoperative period. We retrospectively analyzed patients (N = 263) who received TL between 2004 and 2021. We collected clinical data for fever (>38.0 °C) and blood tests (WBC, CRP, albumin, Hb, neutrophils, lymphocytes) on postoperative days (POD) 3 and 7, and fistulography on POD 7. Clinical data were compared between fistula and no fistula groups, and significant factors were selected using machine learning. Using these clinical factors, we developed improved prediction models for PCF detection. Fistula occurred in 86 (32.7%) patients. Fever was significantly (p < 0.001) more common in the fistula group, and ratios (POD 7 to 3) of WBC, CRP, neutrophils, and neutrophils-to-lymphocytes (NLR) were significantly higher (all p ≤ 0.001) in the fistula group than in the no fistula group. Leakage on fistulography was more common in the fistula group (38.2%) than in the no fistula group (3.0%). The area under curve (AUC) of fistulography alone was 0.68, but predictive models using a combination of fistulography, WBC at POD 7, and neutrophil ratio (POD 7/POD 3) showed better diagnostic performance (AUC of 0.83). Our predictive models may detect PCF early and accurately, which could reduce fatal complications following PCF.

Prognostic Significance of the Post-Treatment Neutrophil-to-Lymphocyte Ratio in Pharyngeal Cancers Treated with Concurrent Chemoradiotherapy.

BACKGROUND: Even though the pre-treatment neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) are well-established prognosticators in various cancers including head and neck cancers, there have been relatively few studies on the clinical significance of the post-treatment values. This study aimed to investigate the changes in NLR and PLR after concurrent chemoradiotherapy (CCRT) and to evaluate their prognostic significance in pharyngeal cancers. METHODS: This study was retrospectively conducted on 461 consecutive patients with primary pharyngeal cancer who had received definitive CCRT. Blood test results before and after CCRT were obtained, and the pre- and post-treatment NLR and PLR were calculated. Patient prognosis was evaluated based on overall survival (OS) and relapse-free survival (RFS). RESULTS: After CCRT, the NLR increased from 2.01 (interquartile range (IQR), 1.53-2.62) to 2.69 (IQR, 1.93-3.81), and the PLR increased from 118.84 (IQR, 92.61-151.63) to 193.19 (IQR, 146.28-262.46). Along with high pre-treatment NLR and high pre-treatment PLR, high post-treatment NLR was also significantly associated with worse OS and RFS (p = 0.013 and p = 0.026). In addition, patients with a high ΔNLR (i.e., the difference between pre- and post-treatment NLRs) had significantly worse OS and RFS (p = 0.013 and p = 0.026). However, only a high pre-treatment NLR (hazard ratio (HR), 2.19; 95% confidence interval (CI), 1.17-4.08; p = 0.014), age (HR, 2.16; 95% CI, 1.14-4.08; p = 0.018), and stage IV (HR, 2.11; 95% CI, 1.15-3.89; p = 0.017) were independent prognostic factors for OS in the multivariate analysis. CONCLUSIONS: In patients with pharyngeal cancers, following CCRT, the NLR and PLR increased significantly from pre-treatment values. Like the pre-treatment NLR and PLR, a high post-treatment NLR and a significant increase in NLR were also associated with poor prognosis. Further prospective studies are required to prove the independent significance of the post-treatment NLR and PLR.

Vascularized osseous flaps for head and neck reconstruction: Comparative analysis focused on complications and salvage options.

OBJECTIVES: This study aimed to compare the clinical outcomes of fibular (FFF group) and scapular (SFF group) osseous free flaps for reconstructing head and neck defects for primary surgery and salvage options. METHODS: We analyzed 156 cases of osseous free flaps in 138 patients from a retrospective review of a single institutional database between January 1996 and January 2020 (FFF, 114 cases in 99 patients; SFF, 42 cases in 39 patients). Clinical profiles such as age, sex, primary tumor site, and defect type were investigated in the two groups. In addition, the incidences and types of perioperative complications, flap compromise, and salvage management were compared between the two groups. RESULTS: FFF was used mostly for oromandibular defects, whereas SFF was preferred for maxillary defect reconstruction. The length of hospital stay was longer in the FFF group than in the SFF group. The flap compromise rate was not significantly different between the two groups; however, donor-site complications were not observed in the SFF group as compared to 7.9% in the FFF group. A regional or free (musculo) cutaneous flap was used as a salvage procedure in partial flap compromise. Contralateral SFF was available to replace a completely compromised SFF, whereas it was not feasible in a completely compromised FFF. Cox proportional hazards analysis showed no significant prognostic factors for flap-related complications. CONCLUSION: The two osseous free flaps showed differences in defect type, flap donor complications, and options for compromised flap salvage. These findings must be considered carefully in the preoperative planning stage to guarantee early recovery and timely administration of postoperative adjuvant treatment if necessary.

Endoscopic Debridement of Post-Radiation Nasopharyngeal Necrosis: The Effects of Resurfacing With a Vascularized Flap.

OBJECTIVES: Post-radiation nasopharyngeal necrosis (PRNN) is a serious complication that severely impacts the quality of life and survival of nasopharyngeal carcinoma patients. Endoscopic debridement is considered the first-line treatment for PRNN. This study aimed to analyze clinical outcomes, focusing on the mucosal resurfacing status and the effectiveness of salvage operations. METHODS: Twenty-seven patients who underwent endoscopic debridement were retrospectively analyzed. The patients were divided into two groups according to the initial surgical modality: debridement with a nasoseptal flap (NSF; n=21) and debridement only (no NSF; n=6). Clinical features, postoperative mucosal status, internal carotid artery (ICA) rupture, survival, and final mucosal status were evaluated. The NSF group was categorized according to flap viability to analyze risk factors for flap failure. RESULTS: Regardless of the initial modality, most patients experienced symptom improvement (96.0% for headache and 100% for foul odor); however, complete cranial nerve palsy did not improve in any patients. In the NSF group, complete healing was observed in 66.7%, while all patients in the no-NSF group underwent salvage surgery because none maintained complete healing. In the NSF group, 19.0% of patients required salvage surgery. After the last operation, favorable symptom improvement was noted (100% for headache and 90.0% for foul odor), and 77.8% had completely healed mucosa, whereas only 14.8% and 7.4% had partial healing and persistent necrotic mucosal status. The necrotic or uncovered NSF subgroup showed statistically non-significant tendencies for old age, advanced necrosis stage, advanced T stage, ICA involvement, high frequency and dose of radiation therapy, diabetes mellitus, and underlying comorbidities. Two ICA ruptures and three deaths occurred. CONCLUSION: Resurfacing the nasopharynx with NSF after endoscopic debridement showed better outcomes than debridement only for PRNN treatment. Despite initial NSF failure, additional resurfacing reconstructive surgery offers advantages in symptom mitigation, quality of life, and survival.

Histological features of differentiated dysplasia in the oral mucosa: a review of oral invasive squamous cell carcinoma cases diagnosed with benign or low-grade dysplasia on previous biopsies.

The diagnosis of oral squamous cell carcinoma is sometimes delayed. Recently, the concept of differentiated dysplasia in the oral mucosa was proposed, and we attempted to elucidate the histologic features of differentiated dysplasia in the oral mucosa. Two pathologists reviewed 38 small biopsy cases of patients diagnosed with benign to low-grade dysplasia in the first biopsy, but were diagnosed with invasive carcinoma after excisional biopsy within 2 years. Of these, 29 cases were suspected of having differentiated dysplasia, which histologically showed "abnormal variation in nuclear size and shape," "increased number and size of nucleoli," and "loss of polarity of basal cells." In addition to the features observed in classic dysplasia, "premature keratinization in single cells" and "loss of epithelial cell cohesion" were characteristically observed. These 2 findings were often observed only in the lower half of the epithelium, but not in the full layer of the epithelium. Histological findings of oral differentiated dysplasia were very similar to those of differentiated vulvar intraepithelial neoplasia. "Premature keratinization in single cells" and "loss of epithelial cell cohesion" are specific pathological findings of oral differentiated dysplasia. Oral differentiated dysplasia is considered as a part of the broad spectrum of oral dysplasia that exhibits morphological characteristics different from classic dysplasia rather than being a separate entity. The diagnosis of oral differentiated dysplasia is expected to reduce the delayed diagnosis and improve the prognosis and post-treatment quality of life of patients with oral cavity cancer.

Sentinel Lymph Node Biopsy Versus Elective Neck Dissection: Long-Term Oncologic Outcomes in Clinically Node-Negative Tongue Cancer.

OBJECTIVES: The aim of this study was to compare the long-term oncologic outcomes of sentinel lymph node biopsy (SLNB) versus elective neck dissection (END) in clinically node-negative (cN0) tongue cancer. METHODS: This was a retrospective cohort study of patients with cN0 tongue cancer from a single institution, including 91 patients in the SLNB group and 120 patients in the END group. RESULTS: The overall recurrence rate showed no significant difference between the two groups. The regional control rate was also comparable between the two groups (P=0.490). The 5-year recurrence-free survival (RFS) was slightly better in the SLNB group than in the END group (P=0.427). The 5-year overall survival (OS) rate was 89.9% in the SLNB group versus 91.9% in the END group (P=0.737). In a propensity-matched subgroup analysis, the type of neck management did not affect RFS or OS. CONCLUSION: SLNB showed non-inferior oncologic outcomes compared to END in patients with cN0 tongue squamous cell carcinoma.

Clinical outcomes of bulky parotid gland cancers: need for self-examination and screening program for early diagnosis of parotid tumors.

BACKGROUND: Early detection and diagnosis of parotid gland cancer (PGC) are essential to improve clinical outcomes, because Tumor-Node-Metastasis stage at diagnosis is a very strong indicator of prognosis in PGC. Nevertheless, some patients still present with large parotid mass, maybe due to the unawareness or ignorance of their disease. In this study, we aimed to present the clinical outcomes of bulky PGC (defined by a 4 cm cutoff point for T3-4 versus T1-2 tumors), to emphasize the necessity of a self-examination tool for parotid gland tumor. METHODS: We retrospectively reviewed 60 consecutive cases with bulky (equal to and greater than 4 cm in the longest diameter, determined radiologically) malignant tumors arising from the parotid gland from 1995 to 2016. The clinical and pathological factors were analyzed to identify risk factors for poor outcomes using Cox proportional hazard models. In addition, we designed a self-examination tool for parotid gland tumors, similar to breast self-examination for breast cancer detection. RESULTS: Patients with bulky parotid cancer showed 48.9% 5-year and 24.5% 10-year overall survival rates and a 47.9% risk of high-grade malignancy. The common pathological diagnoses were carcinoma ex pleomorphic adenoma (18.3%), adenocarcinoma (16.7%), mucoepidermoid carcinoma (16.7%), salivary duct carcinoma (16.7%), and adenoid cystic carcinoma (11.7%). Survival analyses revealed that tumor size (hazard ratio, HR = 1.262 upon increase of 1 cm, 95% confidence interval, 95%CI 1.059-1.502), lymph node metastasis (HR = 2.999, 95%CI 1.048-8.583), and high tumor grade (HR = 4.148, 95%CI 1.215-14.154) were independent prognostic factors in multivariable analysis. Functional preservation of the facial nerve was possible only in less than half of patients. CONCLUSION: In bulky PGC, lymph node metastasis at diagnosis and high tumor grade indicated poor survival outcomes, and functional outcomes of the facial nerve were suboptimal. Thus, a public effort seems to be necessary to decrease these patients with bulky PGC, and to increase patients' self-awareness of their disease. As a way of early detection, we proposed a parotid self-examination tool to detect parotid gland tumors at an early stage, which is similar to breast self-examination.

Adenocarcinoma of the minor salivary gland with concurrent MAML2 and EWSR1 alterations.

Salivary gland tumors are histologically diverse, and each entity has distinctive histopathological and molecular features. We report two cases of salivary gland tumors with unique histological and molecular findings, which have not been documented previously. The tumors were located in the base of the tongue in both patients. Most tumor cells were arranged in cords and nests, giving a trabecularlike appearance. Focally, glandular structures with intraluminal mucin and perivascular pseudorosette-like configurations were identified. Tumor cells had eosinophilic to clear cytoplasm, and showed mild nuclear atypia. They were positive for pancytokeratin and negative for S-100, p63, c-KIT, androgen receptor, and neuroendocrine markers. Multiple foci of capsular or lymphovascular invasion were identified, but the Ki-67 labeling index was low (< 5%). Fluorescence in situ hybridization revealed concurrent alterations of MAML2 and EWSR1 gene. Further investigations with a larger number of cases with similar histological and molecular features will accurately classify this tumor.

Induction chemotherapy followed by concurrent chemoradiotherapy versus CCRT for locally advanced hypopharynx and base of tongue cancer.

BACKGROUND/AIMS: Clinical trials have not consistently supported the use of induction chemotherapy (IC) for locally advanced head and neck squamous cell cancer. Hypopharynx and base of tongue (BOT) cancer has shown relatively poor survival. We investigated the role of IC in improving outcome over current chemoradiotherapy (CRT) in patients with hypopharynx and BOT cancer. METHODS: Treatment-naïve patients with stage III/IV (M0) hypopharynx or BOT cancer were randomly assigned to receive CRT alone (CRT arm: cisplatin 100 mg/m2 on D1 3-weekly, two times plus radiotherapy 68.4 Gy/30 fractions on weekdays) versus two 21-day cycles of IC with TPF (docetaxel & cisplatin 75 mg/m2 on D1, and fluorouracil 75 mg/m2 on D1-4) followed by the same CRT regimen (IC arm). The primary endpoint was progression-free survival (PFS). RESULTS: This study closed early after enrollment of 36 patients (19 in the CRT arm, 17 in the IC arm). After a median follow-up of 47.2 months, there was no significant difference in PFS: the median PFS was 26.8 months for the CRT arm and was not reached for the IC arm (p = 0.13). However, the survival curves were widely separated with a plateau after 3 years, suggesting a potential survival benefit from IC: 3-year PFS rates were 45% and 68%, and 3-year overall survival rates were 56% and 86%, in the CRT and IC arms, respectively. CONCLUSION: This study failed to demonstrate that induction TPF chemotherapy improves survival in patients with BOT and hypopharynx cancer. However, it suggested a favorable outcome with IC to this population.

Clinical Outcome of Minor Salivary Gland Cancers in the Oral Cavity: A Comparative Analysis With Squamous Cell Carcinomas of the Oral Cavity.

Purpose: Salivary gland cancer (SGC) in the oral cavity is not common and has been less studied in comparison with oral squamous cell carcinoma (SCC). This study aimed to identify the clinical characteristics and outcomes of SGC in the oral cavity compared with oral SCC. Methods: The medical charts of the patients with SGC (N = 68) arising from minor salivary glands and SCC (N = 750) in the oral cavity between 1995 and 2017 were reviewed retrospectively. The clinical and pathological factors and treatment outcomes were compared to identify clinical differences between oral SGC and SCC in total cases and in tumor size and subsite (propensity score)-matched pairs (N = 68 in each group). In addition, pattern of local invasion was pathologically assessed in a subset of SGC and SCC tumors. Results: Patients with SGC in the oral cavity showed >90% survival at 5 years. Most common pathologies of SGC were mucoepidermoid carcinoma (39.7%) and adenoid cystic carcinoma (35.3%), where high-grade tumors (including adenoid cystic carcinomas having solid components, grade 2 or 3) represented only 36.8%. Compared with oral SCC, surgery for SGC had narrow surgical safety margin. However, local control was very successful in SGC even with <5 mm or positive resection margin through surgery plus adjuvant radiation treatments or surgery alone for small low-grade tumors. Pathologic analysis revealed that the frequency of oral SGC with infiltrative tumor border was significantly lower than that of oral SCC (46.4 vs. 87.2%, P < 0.001). Conclusions: SGC in the oral cavity represents relatively good prognosis and has a locally less aggressive pathology compared with oral SCC. Adjuvant radiation can be very effective to control minimal residual disease in oral SGC. Our study proposed that a different treatment strategy for oral SGC would be reasonable in comparison with oral SCC.

Update on oral and oropharyngeal cancer staging - International perspectives.

Squamous cell carcinoma of the oral cavity and oropharynx have been used synonymously and interchangeably in the world literature in the context of head and neck cancers. As the 21st century progresses, divergence between the two have become more evident, particularly due to evidence related to human papillomavirus-associated oropharyngeal squamous cell carcinoma. As such, the American Joint Committee on Cancer recently published the 8th edition Cancer Staging Manual, serving as a continued global resource to clinicians and researchers. Through changes in staging related to T and N clinical and pathologic classifications, the new system is expected to influence current management guidelines of these cancers that have distinct anatomic and etiopathogenic characteristics. This article aims to review such impactful changes in a time of critical transition of the staging of head and neck cancer and how these changes may affect clinicians and researchers worldwide.

Prevalence of NUT carcinoma in head and neck: Analysis of 362 cases with literature review.

BACKGROUND: Nuclear protein in testis (NUT) carcinoma is a poorly differentiated carcinoma defined by the presence of NUT gene rearrangement. In the head and neck, the true prevalence of NUT carcinoma is unknown. METHODS: We retrospectively investigated NUT expression with clinicopathologic features in 362 patients of poorly differentiated or undifferentiated carcinomas in the head and neck, and reviewed the literature reports. RESULTS: Four (4/362, 1.1%) cases showed strong nuclear expression for NUT-specific monoclonal antibody, and all these tumors were in the sinonasal tract (4/40, 10%). The clinical outcome and histology were diverse unlike previously described. Although previous studies reported different frequency results according to study subjects, frequencies in sinonasal tract are relatively constant (10/80, 12.5%). CONCLUSIONS: This is the largest study on the prevalence of NUT carcinoma in head and neck areas. It is important to include in the differential diagnosis of poorly differentiated carcinoma, particularly in the sinonasal tract.

Incidence of postoperative facial weakness in parotid tumor surgery: a tumor subsite analysis of 794 parotidectomies.

BACKGROUND: The reported incidence of facial weakness immediately after parotid tumor surgery ranges from 14 to 65%. The purpose of this study was to evaluate the incidence of postoperative facial weakness related to parotidectomy with use of preoperative computed tomography (CT), intraoperative facial nerve monitoring, and surgical magnification. Also, we sought to elucidate additional information about risk factors for postoperative facial weakness in parotid tumor surgery, particularly focusing on the tumor subsites. METHODS: We retrospectively reviewed 794 cases with parotidectomy for benign and malignant tumors arising from the parotid gland (2009-2016). Patients with pretreatment facial palsy were excluded from the analyses. Tumor subsites were stratified based on their anatomical relations to the facial nerve as superficial, deep, or both. Multivariable logistic regression analyses were conducted to identify risk factors for postoperative facial weakness. RESULTS: The overall incidences of temporary and permanent (more than 6 months) facial weakness were 9.2 and 5.2% in our series utilizing preoperative CT, intraoperative facial nerve monitoring, and surgical magnification. Multivariable analysis revealed that old age, malignancy, and recurrent tumors (revision surgery) were common independent risk factors for both temporary and permanent postoperative facial weakness. In addition, tumor subsite (tumors involving superficial and deep lobe) was associated with postoperative facial weakness, but not tumor size. Extent of surgery was strongly correlated with tumor pathology (malignant tumors) and tumor subsite (tumors involving deep lobe). CONCLUSION: Aside from risk factors for facial weakness in parotid tumor surgery such as old age, malignant, or recurrent tumors, the location of tumors was found to be related to postoperative facial weakness. This study result may provide background data in a future prospective study and up-to-date information for patient counseling.

Comparison of prognostic implications between the 7th and 8th edition of AJCC TNM staging system for head and neck soft-tissue sarcoma in adult patients.

PURPOSE: This study aimed to investigate the prognostic factors for head and neck soft-tissue sarcoma (HNSTS) in adults, with the comparisons between the 7th and 8th edition of AJCC TNM staging system. METHODS: From a cancer registry of a single, tertiary referral medical center, the medical records of 67 patients treated from February 2005 to December 2017 were reviewed. RESULTS: T1b stage by AJCC 7th edition showed most diverse stage migration by AJCC 8th edition, and T1a or T2b stage by 7th edition remained in T1-3 or T3-4 by 8th edition. T2 stage by 7th edition showed a significantly higher death rate than the T1 stage, with fair discrimination in overall survival. Higher histologic grade and angiosarcoma were significant prognostic factors for recurrence as well as overall survival. Also, nodal and distant metastasis worsen overall survival. CONCLUSIONS: In our series of patients with HNSTS, higher histologic grade, angiosarcoma, N1, and M1 stage significantly increased the risk of recurrence and worse overall survival, which was not evident in revised T stage by AJCC 8th edition.

Rabbit palatum-derived mesenchymal progenitor cells tri-lineage differentiation on 2D substrates and 3D printed constructs.

Hard palate, developed by embryo neural crest stem cells, is a tissue with strong regenerative abilities. It is considered an abundant source of progenitor cells, forming various mesenchymal tissues. Rabbits are more suitable models than murine animals for regenerative preclinical study of the head and neck, owing to their larger size. However, there are no reports of the existence or characteristics of neural crest stem cells in the hard palate of rabbits. In this study, we demonstrate for the first time the presence of nestin-, Sox2-, and p75-positive neural crest stem cells obtained from the hard palate of rabbits and the properties of these cells. Flow cytometry analysis revealed that CD29, CD44, and CD81 were positive; and CD11b, CD34, and CD90 were negative on the ex vivo expanded palatal progenitor cells. Finally, we differentiated them into cells of mesenchymal lineages (bone, cartilage, and fat) in vitro, and in three-dimensional fabricated polycaprolactone and polycaprolactone-tricalcium phosphate scaffolds. Taken together, our data showed the existence of rabbit palatum-derived mesenchymal progenitor cells, and successful fabrication of progenitor cell-loaded biodegradable scaffold using three-dimensional printing. This study will open avenues for new tissue engineering strategies for cell therapy using three-dimensional printing with scaffolds for reconstruction of head and neck defects.