Isoliquiritigenin diminishes invasiveness of human nasopharyngeal carcinoma cells associating with inhibition of MMP-2 expression and STAT3 signalling.

Nasopharyngeal carcinoma (NPC) is prevalent in Asia and exhibits highly metastatic characteristics, leading to uncontrolled disease progression. Isoliquiritigenin (ISL) have attracted attention due to their diverse biological and pharmacological properties, including anticancer activities. However, the impact of ISL on the invasive and migratory ability of NPC remains poorly understood. Hence, this study aimed to investigate the in vitro anti-metastatic effects of ISL on NPC cells and elucidate the underlying signalling pathways. Human NPC cell NPC-39 and NPC-BM were utilized as cell models. Migratory and invasive capabilities were evaluated through wound healing and invasion assays, respectively. Gelatin zymography was employed to demonstrate matrix metalloproteinase-2 (MMP-2) activity, while western blotting was conducted to analyse protein expression levels and explore signalling cascades. Overexpression of signal transducer and activator of transcription 3 (STAT3) was carried out by transduction of STAT3-expressing vector. Our findings revealed that ISL effectively suppressed the migration and invasion of NPC cells. Gelatin zymography and Western blotting assays demonstrated that ISL treatment led to a reduction in MMP-2 enzyme activity and protein expression. Investigation of signalling cascades revealed that ISL treatment resulted in the inhibition of STAT3 phosphorylation. Moreover, overexpression of STAT3 restored the migratory ability of NPC cells in the presence of ISL. Collectively, these findings indicate that ISL inhibits the migration and invasion of NPC cells associating with MMP-2 downregulation through suppressing STAT3 activation. This suggests that ISL has an anti-metastatic effect on NPC cells and has potential therapeutic benefit for NPC treatment.

Post-irradiation dysbiosis in patients with nasopharyngeal carcinoma having received radiotherapy - A pilot study.

OBJECTIVE: To compare the changes in the sinonasal mucosa microbiome in patients with nasopharyngeal carcinoma (NPC) before and after radiotherapy (RT), and to explore the pathogenesis of post-irradiation chronic rhinosinusitis (PI-CRS) and its association with dysbiosis. STUDY DESIGN: Prospective cohort study. SETTING: Unicenter, Tertiary referral hospital. METHODS: Included patients newly diagnosed with NPC. Samples of ostiomeatal complex mucosa were collected before and after RT. Microbiome analysis was conducted using 16S rRNA sequencing, and statistical analysis was performed. Subgroup analyses based on RT modality (proton therapy or photon therapy) RESULTS: Total of 18 patients were enrolled in the study, with 62.1% receiving intensity-modulated proton therapy (IMPT). Corynebacterium was the most dominant genus identified in both the pre- and post-RT groups, with a visible increase in Staphylococcus and a decrease in Fusobacterium genus in post-RT group. Alpha-diversity did not significantly differ between groups, although the beta-diversity analysis revealed a dispersed microbiota in the post-RT group. The functional prediction indicated a higher relative abundance of taxonomies associated with biofilm formation in the post-RT group. The subgroup analysis revealed the above changes to be more significant in patients who received photon therapy (Intensity modulated radiation therapy, IMRT). CONCLUSIONS: This is the first study to analyze the microbiome of patients with NPC after IMPT. We identified similarities between the post-RT microenvironment and that reported in patients with CRS, with a more apparent change noted in patients treated with IMRT. Further investigation is required to further elucidate the pathogenesis of PI-CRS and its relationship to post-RT dysbiosis, particularly IMPT.

Impact of LINC00312 gene polymorphism coupled with habitual risks on buccal mucosa cancer.

Oral squamous cell carcinoma (OSCC) is a prevalent and lethal malignancy with a diverse etiology. LINC00312 is a long intergenic non-coding RNA that functions as a signal hub to regulate the progression and treatment of head and neck cancer. The aim of this study was to evaluate the effect of LINC00312 single nucleotide polymorphisms (SNPs) on the development of oral cancer. Two LINC00312 SNPs, namely rs12497104 and rs164966, were investigated among 469 male patients with cancer of buccal mucosa and 1194 gender- and age-matched controls. No significant correlation was observed between these two SNPs and the occurrence of OSCC in the case and control groups. While assessing the clinicopathological features, carriers of at least one minor allele of rs164966 (GA and GG) were less prone to develop lymph node metastasis (adjusted odds ratio [AOR], 0.666; 95% confidence interval [CI], 0.447-0.991; p=0.045) in comparison with homozygous carriers of the major allele (AA). Subsequent stratifying surveys revealed that this genetic association with nodal spread was seen only in cases who habitually chewed betel quid (AOR, 0.616; 95% CI, 0.386-0.985; p=0.042) or smoked cigarettes (AOR, 0.612; 95% CI, 0.393-0.953; p=0.029), but undetected in cases free of these main behavioral risks. Our results indicate an interactivity of LINC00312 rs164966 with lifestyle-related risks on modulating OSCC progression.

Correlation between coronary heart disease severity and subsequent chronic rhinosinusitis severity: A retrospective cohort study.

Coronary heart disease (CHD) is associated with the development of several diseases. This retrospective population-based cohort study investigated the association between CHD severity and subsequent chronic rhinosinusitis (CRS) of varying severity. We used data from Taiwan's National Health Insurance Research Database. CHD was categorized as severe if treated using a coronary artery bypass graft (CABG) and as mild if treated with percutaneous coronary intervention (PCI). The primary outcome of this study was the development of CRS or severe CRS treated using functional endoscopic sinus surgery. Cox proportional hazards regression was used to calculate adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) for CRS and severe CRS in different patient groups. We included 31,784 patients who received PCI surgery (the CHD-PCI group) and 15,892 patients who received CABG surgery (the CHD-CABG group). A total of 813 and 482 episodes of CRS occurred in the CHD-PCI and CHD-CABG groups, respectively, and 45 and 16 severe CRS events occurred in the CHD-PCI and CHD-CABG groups, respectively. Our multivariable analysis demonstrated that the incidence of CRS in the CHD-CABG group was significantly higher than that in the CHD-PCI group (aHR: 1.196, 95% CI: 1.064-1.280, P = 0.0402), but the two groups had similar incidence rates of severe CRS (aHR: 0.795, 95% CI: 0.456-1.388, P = 0.5534). Subgroup analyses revealed that the association between CHD severity and CRS development was more significant among men (P = 0.0016). In conclusion, we determined that severe CHD treated with CABG was associated with a higher incidence of subsequent CRS, and this association was more prominent among men.

EF-24, a Curcumin Analog, Inhibits Cancer Cell Invasion in Human Nasopharyngeal Carcinoma through Transcriptional Suppression of Matrix Metalloproteinase-9 Gene Expression.

Cancer metastasis is a main cause of failure in treating subjects with nasopharyngeal carcinoma (NPC) and is frequently linked to high death rates. EF-24, an analog of curcumin, has exhibited many anti-cancer properties and enhanced bioavailability over curcumin. Nevertheless, the effects of EF-24 on the invasiveness of NPC are poorly understood. In this study, we demonstrated that EF-24 effectively inhibited TPA-induced motility and invasion responses of human NPC cells but elicited very limited cytotoxicity. In addition, the TPA-induced activity and expression of matrix metalloproteinase-9 (MMP-9), a crucial mediator of cancer dissemination, were found to be reduced in EF-24-treated cells. Our reporter assays revealed that such a reduction in MMP-9 expression by EF-24 was transcriptionally mediated by NF-κB via impeding its nuclear translocation. Further chromatin immunoprecipitation assays displayed that the EF-24 treatment decreased the TPA-induced interaction of NF-κB with the MMP-9 promoter in NPC cells. Moreover, EF-24 inhibited the activation of JNK in TPA-treated NPC cells, and the treatment of EF-24 together with a JNK inhibitor showed a synergistic effect on suppressing TPA-induced invasion responses and MMP-9 activities in NPC cells. Taken together, our data demonstrated that EF-24 restrained the invasiveness of NPC cells through the transcriptional suppression of MMP-9 gene expression, implicating the usefulness of curcumin or its analogs in controlling the spread of NPC.

Lipocalin 2 Reduces MET Levels by Inhibiting MEK/ERK Signaling to Inhibit Nasopharyngeal Carcinoma Cell Migration.

Nasopharyngeal carcinoma (NPC) is the most common cancer that occurs in the nasopharynx, and it is difficult to detect early. The main cause of death of NPC patients is cancer metastasis. Lipocalin 2 (LCN2) has been shown to be involved in a variety of carcinogenesis processes. Here, we aimed to study the role of LCN2 in NPC cells and determine its underlying mechanism. We found that LCN2 was expressed differently in NPC cell lines, namely HONE-1, NPC-39, and NPC-BM. The down-regulation of LCN2 levels by siRNA targeting LCN2 (siLCN2) increased cell migration and invasion in HONE-1 cells, while the up-regulation of LCN2 levels by transfection with the LCN2 expression plasmid decreased cell migration and invasion in NPC-BM cells. Furthermore, LCN2 levels negatively regulated the phosphorylation of MEK/ERK pathways. The treatment of the specific MEK/ERK inhibitor, U0126, reduced cell migration in HONE-1 cells, whereas the treatment of tBHQ, an ERK activator, enhanced cell migration in NPC-BM cells. Based on the bioinformatics data, there was a moderately negative correlation between LCN2 and MET in metastatic NPC tissues (r = -0.5946, p = 0.0022). Indeed, the manipulation of LCN2 levels negatively regulated MET levels in these NPC cells. The treatment of U0126 reduced siLCN2-increased MET levels, while the treatment of tBHQ enhanced LCN2-enhanced MET levels. Interestingly, the down-regulation of MET levels by siMET further decreased siLCN2-enhanced MET levels and cell migration. Therefore, LCN2 inhibits NPC cell migration by reducing MET levels through MEK/ERK signaling.

Risk of Infertility in Males with Obstructive Sleep Apnea: A Nationwide, Population-Based, Nested Case-Control Study.

Obstructive sleep apnea (OSA) yields intermittent hypoxia, hypercapnia, and sleep fragmentation. OSA is associated with chronic medical conditions such as cardiovascular diseases, metabolic syndrome, and neurocognitive dysfunction. However, the risk of infertility in OSA remains unclear due to limited data and lack of long-term population-based studies. The study aims to assess the risk of infertility in obstructive sleep apnea (OSA) by means of a population-based cohort study. The data was utilized from the Taiwan National Health Insurance Research Database (NHIRD) to conduct a population-based cohort study (1997-2013). Compared with the Non-OSA group, the male with OSA and surgery group has the OR (odds ratio) of infertility of 2.70 (95% CI, 1.46-4.98, p = 0.0015), but no significance exists in females with OSA. When the data was stratified according to age and gender, some associations in the specific subgroups were significant. Respectively, males aged 20-35 years old and aged 35-50 years old with a history of OSA and surgery both had a positive association with infertility. (aOR: 3.19; 95% CI, 1.18-8.66, p = 0.0227; aOR: 2.57; 95% CI, 1.18-5.62 p = 0.0176). Male patients with OSA suffer from reduced fertility, but no significant difference was noted in females with OSA. The identification of OSA as a risk factor for male infertility will aid clinicians to optimize long-term medical care. Furthermore, more studies will be encouraged to clarify the effect of OSA on female fertility.

Dihydromyricetin inhibits cancer cell migration and matrix metalloproteinases-2 expression in human nasopharyngeal carcinoma through extracellular signal-regulated kinase signaling pathway.

Nasopharyngeal carcinoma (NPC) is endemic in Southeast Asia and the main cause of treatment failure is metastasis. A lot of biological and pharmacological actions of dihydromyricetin (DHM) have been reported such as regulating glucose and anti-cancer effects. The effects of DHM on the cancer invasion and migration of NPC, however, are still unclear. We therefore investigated the in vitro anti-metastatic properties of DHM on three human NPC cell lines (HONE-1, NPC-39, and NPC-BM), as well as the underlying signaling pathways. Our study revealed that DHM could suppress the migration and invasion in NPC cells. Gelatin zymography assay and western blotting assays demonstrated that DHM suppressed the enzyme activity and protein expression of matrix metalloproteinases-2 (MMP-2). Mitogen-activated protein kinases were also investigated to elucidate the signaling pathway, which showed that phosphorylation of extracellular signal-regulated kinase 1 and 2 (ERK1/2) was inhibited after the treatment of DHM. In conclusion, our data revealed that DHM inhibited the migration and invasion of NPC cells by suppressing the expression of MMP-2 via down regulating the ERK1/2 signaling pathway.

Risk of head and neck cancer in patients with peptic ulcers and the effect of Helicobacter pylori treatment.

It remained inconclusive whether patients with peptic ulcer disease had a higher risk of head and neck cancer (HNC). Therefore, we enrolled 109,360 patients with peptic ulcer disease and matched for age and sex with 218,720 controls from the Taiwan National Health Insurance Research Database between January 1, 1997 and December 31, 2013.The HNC incidence rate was 1.33-fold higher in the peptic ulcer group than in the control group (7.52 vs. 5.68 per 100,00 person-years; crude relative risk: 1.33; 95% confidence interval [CI]: 1.08-1.63) after > 6 years of follow-up. However, in the peptic ulcer subgroup with H. pylori treatment, HNC risk was not significantly different from that of the control group (crude relative risk: 1.12; 95% CI: 0.86-1.46). Moreover, the population with peptic ulcers had the highest risk of laryngeal and hypopharyngeal cancer (adjusted HR: 2.27 [95% CI: 1.16-4.44] and 2.00 [95% CI, 1.13-3.55]), respectively. This observational study suggested that peptic ulcer disease is associated with an increased incidence of laryngeal and hypopharyngeal cancer and H. pylori treatment may have a role in preventing HNC in patients with peptic ulcer disease.

Morusin Suppresses Cancer Cell Invasion and MMP-2 Expression through ERK Signaling in Human Nasopharyngeal Carcinoma.

The most important cause of treatment failure of nasopharyngeal carcinoma (NPC) patients is metastasis, including regional lymph nodes or distant metastasis, resulting in a poor prognosis and challenges for treatment. In the present study, we investigated the in vitro anti- tumoral properties of morusin on human nasopharyngeal carcinoma HONE-1, NPC-39, and NPC-BM cells. Our study revealed that morusin suppressed the migration and invasion abilities of the three NPC cells. Gelatin zymography assay and Western blotting demonstrated that the enzyme activity and the level of matrix metalloproteinases-2 (MMP-2) protein were downregulated by the treatment of morusin. Mitogen-activated protein kinase proteins were examined to identify the signaling pathway, which showed that phosphorylation of ERK1/2 was inhibited after the treatment of morusin. In summary, our data showed that morusin inhibited the migration and invasion of NPC cells by suppressing the expression of MMP-2 by downregulating the ERK1/2 signaling pathway, suggesting that morusin may be a potential candidate for chemoprevention or adjuvant therapy of NPC.

Chronic rhinosinusitis after radiotherapy in patients with head and neck cancer: a population-based cohort study in Taiwan.

BACKGROUND: Chronic rhinosinusitis (CRS) is a common post-radiotherapy (RT) side effect in patients with nasopharyngeal cancer (NPC). However, whether RT is a risk factor for CRS in patients with other types of head and neck cancer remains unclear. This study investigated the association, if any, between CRS and RT in patients with head and neck cancer. METHODS: This retrospective cohort study included the data of patients newly diagnosed as having head and neck cancer between January 1, 2005, and December 31, 2008, from the 2005 Longitudinal Health Insurance Database. Patients were categorized into the following groups according to the treatment regimens received: RT alone (RT-alone), RT combined with other treatments (any-RT), and treatments without RT (no-RT). The outcome was the occurrence of CRS after treatment. RESULTS: Of the 701 patients, 7% experienced CRS within 5 years after initial treatment. Patients were divided into subgroups according to different treatment policies, and the RT-alone group, any-RT group, and no-RT group had 5-year incidence of CRS of 12%, 9.3%, and 4.5%, respectively. Patients in the RT-alone and any-RT groups exhibited an increased risk of CRS compared with patients in the no-RT group (hazard ratio: 6.76 and 2.91; 95% confidence interval: 2.60 to 17.5 and 1.60 to 5.31, respectively). CONCLUSION: This is the first nationwide population-based cohort study to evaluate the risk of posttreatment CRS in patients with head and neck cancer. Our findings indicate that RT is a major risk factor for CRS. Thus, physicians should consider this potential risk in patients with head and neck cancer after RT.

Epigallocatechin-3-gallate inhibits migration of human nasopharyngeal carcinoma cells by repressing MMP-2 expression.

Metastasis of the cancer cells to the regional lymph nodes parts of the body remains an important cause of treatment failure in nasopharyngeal carcinoma (NPC) patients. Epigallocatechin-3-gallate (EGCG), the most important ingredient in the green tea, has been reported to possess antioxidant and anticancer activities. However, the effects of EGCG on NPC cell metastasis are still unclear. In the present study, we examined the in vitro antimetastatic properties of EGCG on human NPC cells, NPC-39, HONE-1 and NPC-BM. The results revealed that EGCG considerably inhibited the migration abilities of three NPC cells. The matrix metalloproteinases-2 (MMP-2) activity and expression were also significantly inhibited by EGCG treatment. Furthermore, EGCG suppressed the phosphorylation of the Src signaling pathway. Moreover, blocking the Src pathway also inhibits MMP-2 expression and migration in the NPC cells. In conclusion, this study revealed that EGCG could inhibit the metastatic activity of human NPC cells by downregulating the protein expression of MMP-2 through modulation of the Src signaling pathway, suggesting that EGCG may be a potential candidate for chemoprevention of NPC.

Factors associated with the true location of ingested fishbones.

OBJECTIVES: Fishbone ingestion is a common problem worldwide, and the first step for managing this condition is to locate the fishbone precisely. However, until now, no study has analysed the true location of fishbone and its associated factors. Thus, this study identified the factors predicting the true location of fishbone and subsequently attempted to provide a management algorithm for fishbone ingestion. PATIENTS AND METHODS: This retrospective study was carried out at St Martin De Porres Hospital, Taiwan, between January 2015 and January 2016. All patients were diagnosed as having fishbone ingestion within the pharynx and underwent fishbone removal. RESULTS: This study included 198 consecutive patients with a mean age of 43.1 years (range: 1-84 years). The sensitivity of lateral neck radiography in the diagnosis of fishbone in the pharynx was only 22%. The fishbone locations were as follows: the tonsil in 72 (36.4%) patients, the tongue base / vallecula in 112 (56.6%) and the hypopharynx in 14 (7.0%). Multiple logistic regression analysis showed that patient age and fishbone length were significant independent risk factors associated with the true location of fishbone ingestion. Among all patients, fishbone was removed transorally under direct vision in 73 (36.9%) patients and using flexible nasopharyngoscopy in 125 (63.1%) patients. CONCLUSION: Patient age and fishbone length are important independent factors associated with the location of ingested fishbone. Lateral neck radiography is not beneficial for diagnosing fishbone ingestion within the pharynx. Flexible nasopharyngoscopy, by contrast, is an important method for the diagnosis and treatment of fishbone ingestion within this location.

Pterygomandibular suspension suture: a simple modification of uvulopalatopharyngoplasty for severe obstructive sleep apnea.

BACKGROUNDS: The aim of this study is to introduce pterygomandibular suspension suture as a simple modification of uvulopalatopharyngoplasty for severe obstructive sleep apnea in dealing with lateral pharyngeal wall and retropalatal space collapse. METHODS: This retrospective study was conducted at Taipei Veterans General Hospital, Taiwan. Ten adult patients underwent modified uvulopalatopharyngoplasty with pterygomandibular suspension suture according to following inclusion criteria: severe obstructive sleep apnea (apnea-hypopnea index [AHI] > 30 events/h), type I Fujita with lateral pharyngeal wall collapse, and failure for continuous positive airway pressure (CPAP) therapy. The philosophy of this modification technique is to create a firm anterolateral suspension of the lateral pharyngeal wall and soft palate by sutures. RESULTS: The mean operative time of modified uvulopalatopharyngoplasty with pterygomandibular suspension suture was 60 min. The mean AHI decreased significantly from 77.2 ± 25.0 preoperatively to 28.7 ± 18.8 postoperatively (P = 0.005) and the lowest oxygen saturation increased from 69.9 ± 11.4 to 81.1 ± 7.19% (P = 0.005). No major perioperative complication such as massive bleeding or respiratory distress was noted. No patient experienced a swallowing disturbance, taste change, or voice change 6 months postoperatively. The mean period for resuming a normal diet was 15 days. CONCLUSION: Modified uvulopalatopharyngoplasty with pterygomandibular suspension suture is a simplified and effective surgical approach with satisfactory functional recovery for selective patients with severe obstructive sleep apnea.

Phytoplasma SAP11 alters 3-isobutyl-2-methoxypyrazine biosynthesis in Nicotiana benthamiana by suppressing NbOMT1.

Phytoplasmas are bacterial phytopathogens that release virulence effectors into sieve cells and act systemically to affect the physiological and morphological state of host plants to promote successful pathogenesis. We show here that transgenic Nicotiana benthamiana lines expressing the secreted effector SAP11 from Candidatus Phytoplasma mali exhibit an altered aroma phenotype. This phenomenon is correlated with defects in the development of glandular trichomes and the biosynthesis of 3-isobutyl-2-methoxypyrazine (IBMP). IBMP is a volatile organic compound (VOC) synthesized by an O-methyltransferase, via a methylation step, from a non-volatile precursor, 3-isobutyl-2-hydroxypyrazine (IBHP). Based on comparative and functional genomics analyses, NbOMT1, which encodes an O-methyltransferase, was found to be highly suppressed in SAP11-transgenic plants. We further silenced NbOMT1 through virus-induced gene silencing and demonstrated that this enzyme influenced the accumulation of IBMP in N. benthamiana In vitro biochemical analyses also showed that NbOMT1 can catalyse IBHP O-methylation in the presence of S-adenosyl-L-methionine. Our study suggests that the phytoplasma effector SAP11 has the ability to modulate host VOC emissions. In addition, we also demonstrated that SAP11 destabilized TCP transcription factors and suppressed jasmonic acid responses in N. benthamiana These findings provide valuable insights into understanding how phytoplasma effectors influence plant volatiles.

Thyroid carcinoma with rhabdoid phenotype: Case report with review of the literature.

OBJECTIVE: This paper aims to comprehensively document a rare case of thyroid carcinoma with rhabdoid phenotype and literature review of this disease. METHODS: A 59-year-old man presented with a rapidly enlarging, painful left lateral cervical mass. CT scan revealed a tumor over the left the thyroid gland with multiple left cervical lymphadenopathy over left level II-IV and level VI. Fine-needle aspiration cytology reported carcinoma, type undetermined. Total thyroidectomy with central compartment and left neck dissection was performed. RESULTS: Pathology report showed rhabdoid phenotype of thyroid carcinoma. Final staging was pT4N1M1. CONCLUSIONS: Although WHO classification of thyroid tumor histology does not define this disease entity, few cases were reported. In the last 20 years, English literature review revealed only 12 cases about thyroid carcinoma with rhabdoid phenotype. Major treatment of thyroid carcinoma with rhabdoid phenotype is surgery, and the benefit of adjuvant therapies as radiotherapy or systemic chemotherapy is not clear. The prognosis of thyroid carcinoma with rhabdoid phenotype is extremely poor, with mean survival of only 6 months.

Neck observation is appropriate in T1-2, cN0 oral squamous cell carcinoma without perineural invasion or lymphovascular invasion.

OBJECTIVES: Management of cN0 neck, elective neck dissection (END) or observation, remains controversial for T1-2 oral squamous cell carcinoma (OSCC). To allow for the safe observation of cN0 neck, it is mandatory to define predictors with high negative predictive value (NPV) for cervical lymph node (LN) status. MATERIALS AND METHODS: Pathologic re-evaluation was performed in tumors of 253 consecutive patients with T1-2, cN0 OSCC. The predictive roles of pathologic parameters for cervical LN status in guiding neck management were investigated. RESULTS: Cervical LN metastasis (LN+) occurred at a similar rate between observation and END groups (20.8% vs. 22.2%, p=0.807), indicating poor discriminatory value for cervical LN status by clinical judgment. Compared with T classification, tumor thickness and differentiation, PNI/LVI (perineural invasion/lymphovascular invasion) demonstrated the highest NPV (85.5%). Hypothetically using PNI/LVI status to guide neck management, a dramatic reduction in overtreatment rate could be achieved (54.2% to 20.2%), with a minimal increase in undertreatment rate (6.3% to 9.9%). In patients without PNI or LVI (PNI/LVI-), the ultimate neck control rate (96.9% vs. 96.3%, p=1.000) and 5-year disease-specific survival rate (91.1% vs. 92.8%, p=0.863) were equivalent between observation and END. However, a significantly higher incidence of neck recurrence was found with observation (16.9% vs. 6.5%, p=0.031), with 93.8% occurring within one year and 73.3% being successfully salvaged. CONCLUSION: Observation under close follow-up for the first year is appropriate in T1-2, cN0 OSCC without PNI or LVI, for the achievement of equivalent ultimate neck control and 5-year disease-specific survival rates compared with END.