A novel histopathological feature of spatial tumor-stroma distribution predicts lung squamous cell carcinoma prognosis.

We used a mathematical approach to investigate the quantitative spatial profile of cancer cells and stroma in lung squamous cell carcinoma tissues and its clinical relevance. The study enrolled 132 patients with 3-5 cm peripheral lung squamous cell carcinoma, resected at the National Cancer Center Hospital East. We utilized machine learning to segment cancer cells and stroma on cytokeratin AE1/3 immunohistochemistry images. Subsequently, a spatial form of Shannon's entropy was employed to precisely quantify the spatial distribution of cancer cells and stroma. This quantification index was defined as the spatial tumor-stroma distribution index (STSDI). The patients were classified as STSDI-low and -high groups for clinicopathological comparison. The STSDI showed no significant association with baseline clinicopathological features, including sex, age, pathological stage, and lymphovascular invasion. However, the STSDI-low group had significantly shorter recurrence-free survival (5-years RFS: 49.5% vs. 76.2%, p < 0.001) and disease-specific survival (5-years DSS: 53.6% vs. 81.5%, p < 0.001) than the STSDI-high group. In contrast, the application of Shannon's entropy without spatial consideration showed no correlation with patient outcomes. Moreover, low STSDI was an independent unfavorable predictor of tumor recurrence and disease-specific death (RFS; HR = 2.668, p < 0.005; DSS; HR = 3.057, p < 0.005), alongside the pathological stage. Further analysis showed a correlation between low STSDI and destructive growth patterns of cancer cells within tumors, potentially explaining the aggressive nature of STSDI-low tumors. In this study, we presented a novel approach for histological analysis of cancer tissues that revealed the prognostic significance of spatial tumor-stroma distribution in lung squamous cell carcinoma.

Utility of the endobronchial Watanabe spigot for intractable cancer-related pneumothorax: a retrospective observational study.

BACKGROUND: The use of endobronchial Watanabe spigots for intractable secondary pneumothorax in patients with cancer has not been adequate. This study aimed to investigate the use of endobronchial Watanabe spigots for intractable pneumothorax in patients with malignant tumors. METHODS: Consecutive patients with malignant tumors who underwent occlusion with an endobronchial Watanabe spigot for intractable pneumothorax associated with perioperative treatment or drug therapy at our institution between January 2014 and February 2022 were reviewed. RESULTS: Of the 32 cases in which an endobronchial Watanabe spigot was used, six were excluded; we thus evaluated 26 cases in which the chest tube was removed. Chest tubes were removed in 19 cases (73.1%) and could not be removed and required surgical treatment under general anesthesia in seven patients (26.9%), of which four (14.8%) underwent open-window thoracostomy. Half of the patients were treated with both an endobronchial Watanabe spigot and pleurodesis. Although thin-slice chest computed tomography revealed a fistula in 15 patients, the chest tube was removed in 11 (57.9%) patients. A significant difference was only observed in patients with a history of heavy smoking. CONCLUSIONS: The chest tube removal rate was comparable to those reported in previous studies. An endobronchial Watanabe spigot may be a useful treatment option for intractable cancer-related pneumothorax.

Comparison of cystatin C- and creatinine-based estimated glomerular filtration rate to predict coronary heart disease risk in Japanese patients with obesity and diabetes.

The aim of this study is to determine which indicator of chronic kidney disease most closely correlates with 10-year Framingham coronary heart disease (CHD) risk among serum creatinine, serum cystatin C (S-CysC), urine albumin-creatinine ratio (UACR), estimated creatinine-based GFRs (eGFRcre), and estimated CysC-based GFRs (eGFRcys) in patients with obesity and diabetes. Serum creatinine, S-CysC, UACR, and cardio-ankle vascular index (CAVI) were examined in 468 outpatients with obesity and type 2 diabetes, free of severe renal dysfunction or previous history of cardiovascular disease, as a cross-sectional survey using baseline data from the multi-centered Japan Diabetes and Obesity Study. S-CysC and eGFRcys had significantly stronger correlations with the 10-year Framingham CHD risk than serum creatinine, eGFRcre, and UACR (creatinine, ρ = 0.318; S-CysC, ρ = 0.497; UACR, ρ = 0.174; eGFRcre, ρ = -0.291; eGFRcys, ρ = -0.521; P < 0.01 by Fisher's z-test). S-CysC and eGFRcys had significantly stronger correlations with CAVI than serum creatinine, eGFRcre, and UACR (creatinine, ρ = 0.198; S-CysC, ρ = 0.383; UACR, ρ = 0.183; eGFRcre, ρ = -0.302; eGFRcys, ρ = -0.444; P < 0.05 by Fisher's z-test). The receiver operating characteristic curves to distinguish the high-risk patients for CHD revealed significantly larger areas under the curve of S-CysC and eGFRcys than those of serum creatinine, UACR, and eGFRcre (serum creatinine, 0.64; S-CysC, 0.75; UACR, 0.56; eGFRcre, 0.63; eGFRcys, 0.76; P < 0.01). The data suggested that eGFRcys can be more predictive of the 10-year CHD risk than eGFRcre in Japanese patients with obesity and diabetes.

Perioperative sequential monitoring of hemodynamic parameters in patients with pheochromocytoma using the Non-Invasive Cardiac System (NICaS).

Surgical treatment of pheochromocytoma is associated with a high risk of hemodynamic instability. To reduce the risk of perioperative complications, adequate medical treatment to normalize blood pressure and restore blood volume is required. Accurate evaluation of the circulating blood volume (CBV) in perioperative patients with pheochromocytoma is clinically important. In the present study, we adopted whole-body bioimpedance monitoring technique using the Non-Invasive Cardiac System (NICaS), which can non-invasively measure cardiac output (CO) values. NICaS-derived CO values were evaluated in eight preoperative patients with pheochromocytoma and were compared with simultaneous CBV values measured by a conventional indicator dilution method using (131)I-labeled human serum albumin. In these patients with pheochromocytoma, the NICaS-derived CO values were significantly correlated with the CBV values measured by (131)I-labeled human serum albumin (4.86 ± 1.05 L/min vs 4.79 ± 1.02 L; r = 0.906; P = 0.002). Sequential NICaS-derived CO values confirmed that CBV increased after preoperative treatment with an α-blocker, with or without volume loading. The results of this study indicate that NICaS can be used to accurately and non-invasively evaluate the hemodynamic status. By sequential monitoring of NICaS-derived CO values, we are able to confirm whether adequate CBV in a patient with pheochromocytoma is obtained by preoperative medical treatment with α-blockers or volume loading, to avoid perioperative complications.

Plasma free metanephrines in the diagnosis of pheochromocytoma: diagnostic accuracy and strategies for Japanese patients.

Measuring the levels of the plasma free metanephrines (PFMs) represents a recently developed and promising test for the diagnosis of pheochromocytoma in the United States and Europe. As this test has not yet been evaluated in Japan, it is necessary to evaluate the diagnostic efficacy of measuring the levels of PFMs compared with the standard measurement of the urinary excretion of metanephrines (uMNs) whose reliability is well established to detect of pheochromocytoma. A total of 101 Japanese subjects clinically suspected of having pheochromocytoma in were included in this study. Subsequently, we prospectively measured the PFMs levels in all patients, compared with those of biochemical markers of the catecholamine secretion and metabolisms in the plasma and urine. All subjects with adrenal tumors underwent tumor excision. Data were available for 84 of the 101 patients, 47 of whom had histopathologically proven pheochromocytoma and 37 were finally diagnosed with non-pheochromocytoma. The results of comparisons in the accuracy of measurement for diagnosis of pheochromocytoma between PFMs and the urinary excretion of metanephrines (uMNs) were 0.980 VS 0.951 for AUC of receiver operatorating characteristic (ROC) curve, 0.957 VS 0.894 for sensitivity, and 0.973 VS 0.946 for specificity, respectively. Although the differences were small, the results of our study definitely demonstrated that measurement of PFMs was not inferior to standard urinary metanephrines (uMNs) measurement, which is established to be the most reliable biochemical method to detect pheochromocytoma. This study clearly shows measuring the PFMs levels to be a reliable and efficient method for diagnosing pheochromocytoma in Japanese patients, as demonstrated in previous reports.

Visual Field Improvement and Electrode Extrusion Prevention by Extended Endaural Incision With Cavity Obliteration for Cochlear Implantation in Ears After Canal Wall-Down Mastoidectomy: Experience of Four Cases.

There is no global consensus on the surgical technique of cochlear implantation (CI) in ears with an open cavity after canal wall-down (CWD) mastoidectomy. Here, we report CI surgery with an endaural incision for the ears after CWD mastoidectomy. The endaural incision was extended upward to obliterate the open cavity of the temporal fascial flap. The endaural incision was extended downward to close the open cavity inlet. After inserting the implanted electrode, the open cavity was obliterated using a temporal fascial flap, and the cavity was closed at the inlet. We performed this type of CI surgery in four ears in three patients. This extended endaural incision provided an excellent view for pedicling the temporal fascial flap with the superficial temporal artery and for open cavity closure without any serious complications. This technique allowed us to opt for CI surgery of the ears after CWD mastoidectomy.

Understanding the Anomalous Thermoelectric Behavior of Fe-V-W-Al-Based Thin Films.

We investigated the thermoelectric and thermal behavior of Fe-V-W-Al-based thin films prepared using the radio frequency magnetron sputtering technique at different oxygen pressures (0.1-1.0 × 10-2 Pa) and on different substrates (n, p, and undoped Si). Interestingly, at lower oxygen pressure, formation of a bcc-type Heusler structure was observed in deposited samples, whereas at higher oxygen pressure, we have noted the development of an amorphous structure in these samples. Our findings indicate that the moderately oxidized Fe-V-W-Al amorphous thin film deposited on the n-Si substrate possesses a large magnitude of S ∼ -1098 ± 100 µV K-1 near room temperature, which is almost double the previously reported value for thin films. Additionally, the power factor (PF) indicated an enormously large value of ∼33.9 mW m-1 K-2 near 320 K. The thermal conductivity of the amorphous thin film is also found to be 2.75 Wm-1 K-1, which is quite lower compared to bulk alloys. As a result, the maximum figure of merit is estimated to be extremely high, i.e., ∼3.9 near 320 K, which is among one of the highest reported values so far. The anomalously large value of Seebeck coefficient and PF has been ascribed to the unusual composite effect of the metallic amorphous oxide phase and insulating substrate possessing a large Seebeck coefficient.

Extracting interpretable features for pathologists using weakly supervised learning to predict p16 expression in oropharyngeal cancer.

One drawback of existing artificial intelligence (AI)-based histopathological prediction models is the lack of interpretability. The objective of this study is to extract p16-positive oropharyngeal squamous cell carcinoma (OPSCC) features in a form that can be interpreted by pathologists using AI model. We constructed a model for predicting p16 expression using a dataset of whole-slide images from 114 OPSCC biopsy cases. We used the clustering-constrained attention-based multiple-instance learning (CLAM) model, a weakly supervised learning approach. To improve performance, we incorporated tumor annotation into the model (Annot-CLAM) and achieved the mean area under the receiver operating characteristic curve of 0.905. Utilizing the image patches on which the model focused, we examined the features of model interest via histopathologic morphological analysis and cycle-consistent adversarial network (CycleGAN) image translation. The histopathologic morphological analysis evaluated the histopathological characteristics of image patches, revealing significant differences in the numbers of nuclei, the perimeters of the nuclei, and the intercellular bridges between p16-negative and p16-positive image patches. By using the CycleGAN-converted images, we confirmed that the sizes and densities of nuclei are significantly converted. This novel approach improves interpretability in histopathological morphology-based AI models and contributes to the advancement of clinically valuable histopathological morphological features.

Predicting lymph node recurrence in cT1-2N0 tongue squamous cell carcinoma: collaboration between artificial intelligence and pathologists.

Researchers have attempted to identify the factors involved in lymph node recurrence in cT1-2N0 tongue squamous cell carcinoma (SCC). However, studies combining histopathological and clinicopathological information in prediction models are limited. We aimed to develop a highly accurate lymph node recurrence prediction model for clinical stage T1-2, N0 (cT1-2N0) tongue SCC by integrating histopathological artificial intelligence (AI) with clinicopathological information. A dataset from 148 patients with cT1-2N0 tongue SCC was divided into training and test sets. The prediction models were constructed using AI-extracted information from whole slide images (WSIs), human-assessed clinicopathological information, and both combined. Weakly supervised learning and machine learning algorithms were used for WSIs and clinicopathological information, respectively. The combination model utilised both algorithms. Highly predictive patches from the model were analysed for histopathological features. In the test set, the areas under the receiver operating characteristic (ROC) curve for the model using WSI, clinicopathological information, and both combined were 0.826, 0.835, and 0.991, respectively. The highest area under the ROC curve was achieved with the model combining WSI and clinicopathological factors. Histopathological feature analysis showed that highly predicted patches extracted from recurrence cases exhibited significantly more tumour cells, inflammatory cells, and muscle content compared with non-recurrence cases. Moreover, patches with mixed inflammatory cells, tumour cells, and muscle were significantly more prevalent in recurrence versus non-recurrence cases. The model integrating AI-extracted histopathological and human-assessed clinicopathological information demonstrated high accuracy in predicting lymph node recurrence in patients with cT1-2N0 tongue SCC.

Behavioral and clinical correlates of serum bilirubin concentrations in Japanese men and women.

BACKGROUND: A considerable interest has been drawn to potential protective effects of bilirubin against oxidative stress-related diseases. Smoking is known to be associated with lower concentrations of serum bilirubin, but other behavioral correlates of serum bilirubin have not been well studied. In this cross-sectional study, we examined the associations of behavioral and clinical factors with serum total bilirubin in Japanese men and women. METHOD: The study subjects comprised of 4802 men and 6414 women aged 49-76 years who participated in the baseline survey of an ongoing cohort study on lifestyle-related diseases in Fukuoka, Japan. With consideration to time of the day of blood sampling and fasting hours, the associations with smoking, alcohol intake, body mass index, physical activity, coffee, tea, blood pressure, glycated hemoglobin (HbA1c), HDL cholesterol and non-HDL cholesterol with serum bilirubin were evaluated by analysis of covariance and multiple linear regression analysis. RESULTS: While smoking was negatively associated with serum bilirubin, alcohol consumption was positively associated with serum bilirubin in both men and women. Coffee consumption was associated with lower bilirubin concentrations in both sexes. In the multiple linear regression analysis, HDL cholesterol was positively and HbA1c was negatively associated with bilirubin in both men and women, and the associations were more evident in women. CONCLUSION: Smoking, alcohol use and coffee consumption were important behavioral correlates of serum bilirubin in Japanese men and women. Serum HDL cholesterol was a measurable clinical correlate of bilirubin in women.

Reduced arterial stiffness in patients with acromegaly: non-invasive assessment by the cardio-ankle vascular index (CAVI).

In patients with acromegaly, cardiovascular diseases are the most common cause of death. Arterial stiffness is increasingly recognized as a valuable surrogate marker for predicting cardiovascular events. To evaluate the vascular status of acromegalic patients, we used the cardio-ankle vascular index (CAVI) to reflect the arterial stiffness from the heart to the ankles. We analyzed 21 acromegalic patients, comprising five patients with untreated active acromegaly, one patient treated with medication and 15 patients who underwent transsphenoidal surgery. Among the 15 patients with surgery, 10 received additional therapies with dopamine agonists and/or somatostatin analogs. All patients with acromegaly unexpectedly showed significant reductions in the CAVI, indicating reduced arterial stiffness, compared with age- and sex-matched controls, regardless of whether they underwent surgery. There was a significant negative correlation between the CAVI and the serum insulin-like growth factor (IGF)-I level in these patients. Active acromegalic patients were associated with lower CAVI than controlled patients. Sequential measurements of the CAVI and serum IGF-I before and after treatment with octreotide and transsphenoidal surgery revealed that a reduced IGF-I level after treatment was accompanied by CAVI elevation. The present findings indicate that the CAVI is negatively correlated with the serum IGF-I level in acromegaly. These findings are consistent with previous reports indicating that the GH/IGF-I axis reduces peripheral vascular resistance. This non-invasive assessment can reflect the present vascular status and would be a useful marker for evaluation of therapeutic effects in patients with acromegaly.

Estradiol protects hair cells from cisplatin-induced ototoxicity via Nrf2 activation.

Cisplatin-induced ototoxicity is caused by reactive oxygen species. It has been recognized that estradiol (E2) regulates redox balance. However, little is known about the protective mechanisms of E2 against cisplatin-induced ototoxicity. In this study, we investigated the effect of E2 on nuclear factor erythroid 2-related factor 2 (Nrf2)-mediated hair cell protection using the organ of Corti isolated from mice. The organ of Corti collected from C57BL/6 mice at 3-5 postnatal days was used in all experiments. The organ of Corti was exposed to 20 µM cisplatin with/without 100 nM E2 to examine the effect of E2 on cisplatin-induced hair cell loss. The mRNA expression of Nrf2 and the phase II detoxification gene after E2 and cisplatin treatment was analyzed using quantitative real-time PCR. E2 significantly reduces cisplatin-induced cochlear hair cell death. In addition, 100 nM E2 increased the mRNA expression of Nrf2 and phase II detoxification genes in the organ of Corti under cisplatin treatment. Our results suggest that E2 activates Nrf2, phase II detoxification enzymes and exerts a protective effect against cisplatin-induced ototoxicity.

Endoscopic observation of pharyngeal mucosal suture healing process after total laryngectomy: case series.

BACKGROUND: Pharyngocutaneous fistula (PCF), a major complication of total laryngectomy, is caused by pharyngeal repair failure. OBJECTIVE: Assess the usefulness of endoscopic observation of the pharyngeal suture's healing process for the early detection of PCF development. METHODS: Pharyngeal mucosal sutures were endoscopically observed postoperatively in patients who underwent total laryngectomy with primary closure. RESULTS: Postoperatively, a white coat adhered to the pharyngeal mucosal suture of all patients. In most cases, the white coat gradually receded, which was considered to be a normal healing process. Thickening of the white coat and/or dehiscence of surgical wound were interpreted as 'poor healing conditions'. Three cases were judged to have developed poor healing conditions of the pharyngeal mucosal suture and one patient developed PCF. The other two patients did not develop PCF, possibly due to early detection of 'poor healing condition' and conservative approach, such as discontinuation of oral intake. CONCLUSIONS: Postoperative poor healing conditions of the pharyngeal mucosal suture may be precursors to PCF development. Endoscopic observation enables early detection of these conditions and may enable the prevention of PCF.

Elevation of C-reactive protein during concurrent chemoradiotherapy is a poor predictive factor for head and neck cancer.

OBJECTIVE: The prognostic role of pretreatment C-reactive protein (CRP) has been reported for head and neck cancer. However, little is known about the relationship between the changes in CRP levels during treatment and prognosis. This study aimed to investigate the correlation between CRP elevation during concurrent chemoradiotherapy (CCRT) and survival outcomes. METHODS: The medical records of patients with oropharyngeal, hypopharyngeal, and laryngeal cancer treated with CCRT at the University of Tsukuba Hospital and National Hospital Organization Mito Medical Center from April 2014 to December 2019 were retrospectively reviewed. Patients were divided into normal (<0.3 mg/dl) and elevated (≥0.3 mg/dl) CRP groups according to the CRP level after the first cycle of cisplatin. The primary endpoint was progression-free survival (PFS). RESULTS: A total of 74 patients were enrolled, of whom 36 (49%) showed elevated CRP levels after the first cycle of cisplatin. The 3-year PFS was 83.3% and 61.0% in the normal and elevated CRP groups, respectively, showing significant differences between the two groups. CONCLUSION: Elevated CRP levels after the first cycle of cisplatin is an objective predictive marker for survival in patient with head and neck squamous cell carcinoma treated with CCRT.

Effect of Average Relative Humidity on Epistaxis.

Background Epistaxis is a very common symptom. The occurrence of epistaxis may be affected by dry environments, but there are some differences among previous reports and this view is controversial. Objective We investigated the relationship between the number of epistaxes and daily average relative humidity. Methods Data on patients with epistaxis between March 2011 and February 2021 were collected from two hospitals. The daily average relative humidity was examined, and the change in the number of patients with epistaxis due to humidity was investigated using a generalized linear mixed model. Results A total of 4184 cases of epistaxis were identified. The number of epistaxis cases per day was significantly associated with the daily average relative humidity (p < 0.001). One percent increment in average relative humidity decreases the number of epistaxis cases per day by 1.1%. Conclusion A negative correlation was found to exist between daily average relative humidity and occurrences of epistaxis.

The area of residual tumor predicts esophageal squamous cell carcinoma prognosis following neoadjuvant chemotherapy.

PURPOSE: To clarify the utility of the area of residual tumor for patients with esophageal squamous cell cancer treated with neoadjuvant chemotherapy. METHODS: We enrolled 186 patients with esophageal squamous cell cancer who underwent surgical resection following neoadjuvant chemotherapy at our hospital. Using digital images, we measured the area of residual tumor at the maximum plane of the specimen and divided the patient into three groups as follows: 0 (area = 0 mm2), low (area = 0-40 mm2), and high (area ≥ 40 mm2). The clinicopathological factors and prognosis were compared among these groups. RESULTS: The median area of the residual tumor was 15.0 mm2　(range 0-1,448.8 mm2). Compared with the 0 and low group, the high group was significantly associated with poorer recurrence-free survival (all P < .001) and overall survival (P < .001 [vs. 0] and P = .017 [vs low]). The area of residual tumor, ypN, tumor regression grade, and lymphovascular invasion were independent predictors of recurrence-free survival. By dividing the patients using a combination of the area of residual tumor and lymphovascular invasion, the high and/or lymphovascular invasion ( +) group displayed significantly poor recurrence-free survival than the 0 group and low/lymphovascular invasion ( -) group. However, there was no significant difference in the recurrence-free survival between the 0 group and low/lymphovascular invasion ( -) group. CONCLUSION: The area of residual tumor is a promising histopathological prognostic factor for patients with esophageal squamous cell cancer treated with neoadjuvant chemotherapy. Moreover, it is a possible candidate histopathological factor for postoperative chemotherapy selection.

Smad2 protein disruption in the central nervous system leads to aberrant cerebellar development and early postnatal ataxia in mice.

Smad2 is a critical mediator of TGF-ß signals that are known to play an important role in a wide range of biological processes in various cell types. Its role in the development of the CNS, however, is largely unknown. Mice lacking Smad2 in the CNS (Smad2-CNS-KO) were generated by a Cre-loxP approach. These mice exhibited behavioral abnormalities in motor coordination from an early postnatal stage and mortality at approximately 3 weeks of age, suggestive of severe cerebellar dysfunction. Gross observation of Smad2-CNS-KO cerebella demonstrated aberrant foliations in lobule IX and X. Further analyses revealed increased apoptotic cell death, delayed migration and maturation of granule cells, and retardation of dendritic arborization of Purkinje cells. These findings indicate that Smad2 plays a key role in cerebellar development and motor function control.

Behavioral and clinical correlates of high-sensitivity C-reactive protein in Japanese men and women.

BACKGROUND: Inflammation has been implicated in the pathogenesis of cardiovascular disease, type 2 diabetes mellitus and cancer. Serum concentration of high-sensitivity C-reactive protein is a good biomarker of chronic low-grade inflammation. Few studies have evaluated relative importance of behavioral and clinical covariates of high-sensitivity C-reactive protein in Japanese population. METHODS: The study subjects were men and women aged 49-76 years from the cohort study of lifestyle-related diseases between February 2004 and July 2006. Analysis of covariance and multiple linear regression analysis were used to estimate geometric means of high-sensitivity C-reactive protein and trends of association. RESULTS: Smoking, body mass index, hypertension, type 2 diabetes mellitus, elevated non-high density lipoprotein cholesterol, prudent dietary pattern were independently associated with serum high-sensitivity C-reactive protein in both men and women. High-sensitivity C-reactive protein concentrations were lowest in men with a moderate intake of alcohol (<30 mL/day). In men, smoking and body mass index accounted for 28% and 26% of the variation in high-sensitivity C-reactive protein, respectively, while body mass index accounted for 60% of the variation of high-sensitivity C-reactive protein in women. CONCLUSIONS: Smoking and body mass index in men, and body mass index in women, were major correlates of serum high-sensitivity C-reactive protein in Japanese people.

Pheochromocytoma crisis caused by Campylobacter fetus.

Pheochromocytoma crisis is a life-threatening endocrine emergency associated with symptoms of excess release of catecholamines. It might present spontaneously or be unmasked by triggers including trauma, surgery and certain medications that provoke catecholamine release by tumors. Here we report a case of pheochromocytoma crisis associated with abscess formation in the tumor and bacteremia of Campylobacter fetus, which was successfully treated with antibiotics and a surgical resection. This case appears to be the first reported case in the literature of abscess formation by C. fetus in pheochromocytoma, leading to catecholamine crisis.

Is elective neck dissection necessary for patients with cT3-4N0 parotid gland cancer?

OBJECTIVE: Management of the cervical lymph nodes in patients with cT3-4N0 parotid gland cancer (PGC) has been controversial. This study investigated the need for elective neck dissection (END) in patients with cT3-4N0 PGC. METHODS: We retrospectively examined cervical lymph node metastasis, overall survival (OS), and disease-free survival (DFS) rates in 40 patients with cT3-4N0 PGC according to whether or not END was performed. RESULTS: Cervical lymph node metastasis occurred in 27.5% of patients and level II was the most common area. Recurrence could be treated by salvage neck dissection. There was no significant difference in OS (P=0.581) or DFS (P=0.728) between the group that underwent END and the group that did not. CONCLUSION: END at level II is worth performing because of the occult lymph node metastasis rate. The area of neck dissection should be limited because there is no evidence that END improves the prognosis of cT3-4N0 PGC.