A molecular interpretation of the toughness of multiple network elastomers at high temperature.

SignificanceSoft materials can be toughened by creating dissipative mechanisms in stretchy matrixes. Yet using them over a wide range of temperatures requires dissipative mechanisms independent of stretch rate or temperature. We show that sacrificial covalent bonds in multiple network elastomers are most useful in toughening elastomers at high temperature and act synergistically with viscoelasticity at lower temperature. We do not attribute this toughening mechanism only to the scission of bonds during crack propagation but propose that the highly stretched network diluted in a stretchy matrix acts by simultaneously stiffening the elastomer and delaying the localization of bond scission and the propagation of a crack. Such a toughening mechanism has never been proposed for elastomers and should guide network design.

Development of a reliable surgical quality assurance tool for gastrectomy in oncological trials.

BACKGROUND: Despite its recognized importance, there is currently no reliable tool for surgical quality assurance (SQA) of gastrectomy in surgical oncology. The aim of this study was to develop an SQA tool for gastrectomy and to apply this tool within the ADDICT Trial in order to assess the extent and completeness of lymphadenectomy. METHODS: The operative steps for D1+ and D2 gastrectomy have been previously described in the literature and ADDICT trial manual. Two researchers also performed fieldwork in the UK and Japan to document key operative steps through photographs and semi-structured interviews with expert surgeons. This provided the steps that were used as the framework for the SQA tool. Sixty-two photographic cases from the ADDICT Trial were rated by three independent surgeons. Generalizability (G) theory determined inter-rater reliability. D-studies examined the effect of varying the number of assessors and photographic series they rated. Chi-square assessed intra-rater reliability, comparing how the individual assessor's responses corresponded to their global rating for extent of lymphadenectomy. RESULTS: The tool comprised 20 items, including 19 anatomical landmarks and a global rating score. Overall reliability had G-coefficient of 0.557. Internal consistency was measured with a Cronbach's alpha score of 0.869 and Chi-square confirmed intra-rater reliability for each assessor as < 0.05. CONCLUSIONS: A photographic surgical quality assurance tool is presented for gastrectomy. Using this tool, the assessor can reliably determine not only the quality but also the extent of the lymphadenectomy performed based on remaining anatomy rather than the excised specimen.

Dual blockade of IL-4 and IL-13 with dupilumab ameliorates sensorineural olfactory dysfunction in mice with eosinophilic sinonasal inflammation.

BACKGROUND: Dupilumab, an antibody that binds IL-4Rα and inhibits IL-4 and IL-13 signals, has demonstrated efficacy in chronic rhinosinusitis with nasal polyps (CRSwNP) primarily characterized by type 2 inflammation. Current evidence suggests that the rate of improvement in olfactory dysfunction with dupilumab exceeds that of nasal polyp reduction, yet the underlying mechanism remains undisclosed. We hypothesize that dupilumab may initially ameliorate sensorineural olfactory dysfunction. METHODOLOGY: Male BALB/c mice were intranasally administered ovalbumin and Aspergillus protease for 12 weeks to induce eosinophilic sinonasal inflammation. Dupilumab treatment was also administered. The mice underwent histological assessment, olfactory behavioural test, and gene expression profiling to identify neuroinflammatory markers within the olfactory bulb. RESULTS: Dupilumab treatment resulted in a reduction in the number of mucosal protruding lesions, as well as decreased infiltration of eosinophils and neutrophils, along with a decrease in olfactory sensory neuron injury. Furthermore, there was a downregulation in the mRNA expression related to microglia activation and neuroinflammation in the olfactory bulb. CONCLUSIONS: Dupilumab improves the sensorineural pattern of olfactory dysfunction in mice, potentially explaining why olfaction improves more rapidly than polyp reduction in patients with CRSwNP.

Differences of bioelectrical impedance in the development and healing phase of pressure ulcers and erythema in mouse model.

Pressure ulcers (PUs) are economically burdensome medical conditions. Early changes in pressure ulcers are associated with erythema. In this study, bioelectrical impedance was used to measure the differences between PUs and blanchable erythema. We divided 21 ICR mice into three groups: control, 1000 mmHg-1h, and 1000 mmHg-6h. Healthy skin, blanchable erythema, and PUs were induced on the dorsal skin. The results indicated an immediate increase in impedance, resistance, and reactance values in the pressure group after release, followed by a subsequent decrease until two days after release. Compared with the control group, impedance and reactance significantly increased by 30.9% (p < 0.05) and 30.1% (p < 0.01), respectively, in the 6 h-loading group immediately after release. One and two days after release, the 1 h-loading and 6 h-loading groups exhibited significantly different degrees of decline. One day after release, impedance and resistance decreased by 30.2% (p < 0.05) and 19.8% (p < 0.05), respectively, in the 1 h-loading group; while impedance, resistance, and reactance decreased by 39.2% (p < 0.01), 26.8% (p < 0.01), and 45.7% (p < 0.05), respectively, in the 6 h-loading group. Two days after release, in the 1 h-loading group, impedance and resistance decreased by 28.3% (p < 0.05) and 21.7% (p < 0.05), respectively; while in the 6 h-loading group, impedance, resistance, and reactance decreased by 49.8% (p < 0.001), 34.2% (p < 0.001), and 59.8% (p < 0.01), respectively. One and two days after release the pressure group reductions were significantly greater than those in the control group. Additionally, we monitored changes during wound healing. Distinguishing early PUs from blanchable erythema by noninvasive bioelectrical impedance technology may have applications value in early assessment of PUs.

Total knee replacement in osteoarthritis patients on reducing the risk of major adverse cardiac events: a 18-year retrospective cohort study.

OBJECTIVES: Osteoarthritis (OA) is a common degenerative joint disease, and total knee replacement (TKR) is a successful surgical intervention for knee OA treatment. However, the risks of mortality and major cardiovascular events (MACEs) in patients receiving TKR remain unclear. This study investigated the risks of mortality and MACEs in knee OA patients who received TKR. METHODS: For this population-based cohort study, the Longitudinal Health Insurance Database 2000 was used. Two million individuals with knee OA defined by ICD-9-CM codes who received physical therapy between 1999 and 2017 were selected. For propensity score matching (PSM), we considered the year of knee OA diagnosis, demographics, comorbidities, co-medications, and knee OA-related hyaluronic acid or physical therapy at baseline. After PSM, regression analyses were performed to assess the association of mortality or MACEs with TKR and non-TKR individuals. RESULTS: We identified patients (n = 189,708) with a new diagnosis of knee OA between 2000 and 2017. In total, 10,314 propensity-score-paired TKR and non-TKR individuals were selected. The PSM cohort algorithm revealed that the risk of mortality or MACEs was lower in the TKR group (adjusted hazard ratio: 0.791; 95% confidence interval: 0.755-0.830) than in the non-TKR group. CONCLUSIONS: Patients with knee OA who received TKR had decreased risks of mortality and MACEs than those who did not receive TKR. Moreover, the TKR group received a reduced dosage of nonsteroidal anti-inflammatory drugs at the 1-year follow-up.

Erratum: Coherent Excitation of the Highly Forbidden Electric Octupole Transition in

This corrects the article DOI: 10.1103/PhysRevLett.125.163001.

Structure and Functional Differences of Cysteine and 3-Mercaptopropionate Dioxygenases: A Computational Study.

Thiol dioxygenases are important enzymes for human health; they are involved in the detoxification and catabolism of toxic thiol-containing natural products such as cysteine. As such, these enzymes have relevance to the development of Alzheimer's and Parkinson's diseases in the brain. Recent crystal structure coordinates of cysteine and 3-mercaptopropionate dioxygenase (CDO and MDO) showed major differences in the second-coordination spheres of the two enzymes. To understand the difference in activity between these two analogous enzymes, we created large, active-site cluster models. We show that CDO and MDO have different iron(III)-superoxo-bound structures due to differences in ligand coordination. Furthermore, our studies show that the differences in the second-coordination sphere and particularly the position of a positively charged Arg residue results in changes in substrate positioning, mobility and enzymatic turnover. Furthermore, the substrate scope of MDO is explored with cysteinate and 2-mercaptosuccinic acid and their reactivity is predicted.

Coherent Excitation of the Highly Forbidden Electric Octupole Transition in

We report on the first coherent excitation of the highly forbidden ^{2}S_{1/2}→^{2}F_{7/2} electric octupole (E3) transition in a single trapped ^{172}Yb^{+} ion, an isotope without nuclear spin. Using the transition in ^{171}Yb^{+} as a reference, we determine the transition frequency to be 642 116 784 950 887.6(2.4) Hz. We map out the magnetic field environment using the forbidden ^{2}S_{1/2}→^{2}D_{5/2} electric quadrupole (E2) transition and determine its frequency to be 729 476 867 027 206.8(4.4) Hz. Our results are a factor of 1×10^{5} (3×10^{5}) more accurate for the E2 (E3) transition compared to previous measurements. The results open up the way to search for new physics via precise isotope shift measurements and improved tests of local Lorentz invariance using the metastable ^{2}F_{7/2} state of Yb^{+}.

Association of use of Chinese herbal medicines and the risk of fracture in patients with osteoporosis: a population-based cohort study.

After utilizing a large population-based claims database and the application of propensity score match approach to reduce the confounding effects, we found that the use of Chinese herbal medicines (CHMs) was related to the lower risk of sequent osteoporotic fracture by 27% among the individuals with osteoporosis. The predominant effect was observed in those receiving CHMs for more than two years. INTRODUCTION: Osteoporosis (OS) is a highly disabling condition that can lead to fragility fracture, thus posing greater burdens of functional limitations for the affected individuals. It is unclear if the use of Chinese herbal medicines (CHMs) could reduce the risk of fracture due to OS. This study aimed to investigate the association of CHMs and the subsequent osteoporotic fracture risk among OS patients. METHODS: This longitudinal cohort study used the Taiwanese National Health Insurance Research Database to identify 250,699 newly diagnosed OS patients aged 20 years or older between 1998 and 2010. We recruited 103,325 CHM users following the onset of OS (CHM users) and randomly selected 103,325 subjects without CHM usage as controls (non-CHM users) by propensity score matching according to the demographic characteristics and comorbidities at enrollment. All enrollees were followed until the end of 2012 to record the incidence of osteoporotic fracture. We applied the Cox proportional hazard regression model to compute the hazard ratio (HR) of the risk of osteoporotic fracture. RESULTS: During the 15-year follow-up period, 7208 CHM users and 11,453 non-CHM users sustained osteoporotic fracture, with an incidence rate of 9.26 and 12.96, respectively, per 1000 person-years. We found that CHM users had a significantly reduced risk of osteoporotic fracture compared to non-CHM users (adjusted HR 0.73; 95% confidence interval [CI] = 0.70-0.75). Those treated with CHMs for longer than 730 days had a lower fracture risk by 54%. Some commonly used CHMs, such as Yan hu suo (Rhizoma Corydalis), Huang Qin (Scutellaria Baicale), Jie Geng (Platycodon grandifloras), Xiang Fu (Cyperus rotundus), Hai Piao Xiao (Cuttlebone Sepium), Jia-Wei-Xiao-Yao-San, Ge-Gen-Tang, Shao-Yao-Gan-Cao-Tang, and Du-Huo-Ji-Sheng-Tang, are related to the lower risk of fracture. CONCLUSIONS: The use of CHMs was associated with lower risk of osteoporotic fracture for OS patients, suggesting that it could be integrated into conventional therapy to prevent subsequent bone fracture.

Do dysplastic proximal resection margins predict the risk of anastomotic recurrence and overall survival in patients with esophageal squamous cell carcinoma?

Positive proximal resection margins are strongly associated with anastomotic recurrence in esophageal cancer. However, the prognostic significance of dysplastic proximal resection margins remains unclear. The aim of this study is to investigate whether the dysplastic proximal resection margin can predict anastomotic recurrence and overall survival in patients with esophageal squamous cell carcinoma. Between 2000 and 2014, patients with esophageal squamous cell carcinoma who received a nonpalliative resection and survived the perioperative period were included. Two expert pathologists independently reviewed the proximal resection margin status, which was classified as negative, dysplastic, or positive. The kappa statistic was used to test interobserver reliability. Anastomotic recurrence and overall survival served as the main outcome measures. The study cohort consisted of 469 patients (445 males and 27 females). There was an excellent interobserver agreement for negative (kappa = 0.88), dysplastic (kappa = 0.88), and positive (kappa = 1) proximal resection margins-which were identified in 418 (89.1%), 37 (7.9%), and 14 (3.0%) patients, respectively. After a median follow-up of 21.6 months, 30 (6.4%) patients developed an anastomotic recurrence. Compared with patients with negative proximal resection margins (24/418, 5.7%), the occurrence of anastomotic recurrence was more commonly observed in those with positive proximal resection margins (3/14, 21.4%, P = 0.017) but not in those with dysplastic proximal resection margins (3/37, 8.1%, P = 0.56). Multivariable Cox regression analysis identified positive proximal resection margins (hazard ratio: 5.93, P = 0.010) and advanced clinical stage (hazard ratio: 12.04, P = 0.023) as independent risk factors for anastomotic recurrence. Dysplastic proximal resection margins were not retained in the model as an independent predictor (hazard ratio: 1.38, P = 0.602). The 5-year overall survival rates of patients with negative (38.2%) and dysplastic margins (27.0%) were similar (P = 0.814), and significantly higher than that observed in those with positive proximal resection margins (9.5%, P = 0.015). In conclusion, dysplastic proximal resection margins can be identified in at least 7.9% of patients with esophageal squamous cell carcinoma, but neither they are associated with an increased risk of anastomotic recurrence nor they portend a poor overall survival.

Periodontitis and dental scaling associated with pyogenic liver abscess: A population-based case-control study.

BACKGROUND AND OBJECTIVES: The purpose of this study was to investigate the relationship between periodontitis, dental scaling (DS) and pyogenic liver abscesses (PLAs). MATERIAL AND METHODS: A nationwide population-based case-control study was applied using data from the National Health Insurance Research Database in Taiwan. We identified and enrolled 691 PLA patients, who were individually matched by age and sex to 2764 controls. RESULTS: Conditional logistic regression was applied to estimate adjusted odds ratios (aORs) in patients with exposure to periodontitis and DS before PLA. After adjusting for other confounding factors, periodontitis remained a risk factor for PLA among patients aged 20-40 years, with an aOR of 2.31 (95% confidence interval [CI] = 1.37-3.90, P = .0018). In addition, the average aOR for PLA was significantly lower among patients with one DS (aOR = 0.76, 95% CI = 0.59-0.96) and more than one DS (aOR = 0.61, 95% CI = 0.39-0.95) within 1 year before the index date. CONCLUSION: According to these results, we concluded that adult patients with periodontitis aged <50 years old are more at risk for PLA than controls, particularly when they have no DS. Moreover, from 20 years of age, non-periodontal patients subjected to at least 2 DS per year are less at risk for PLA than controls.

Risk of epilepsy in surgical patients undergoing general or neuraxial anaesthesia.

Limited information is available on the risks of epilepsy after surgery in patients receiving general or neuraxial anaesthesia. Using Taiwan's National Health Insurance Research Database, we identified 1,478,977 patients aged ≥ 20 years who underwent surgery (required general or neuraxial anaesthesia with hospitalisation for more than one day) between 2004 and 2011. We selected 235,066 patients with general anaesthesia and 235,066 patients with neuraxial anaesthesia using a frequency-matching procedure for age and sex. We did not study those with co-existing epilepsy-related risk factors. The adjusted rate ratios (RRs) and 95% confidence intervals (CIs) of newly diagnosed epilepsy 1 year after surgery associated with general anaesthesia were analysed in the multivariate Poisson regression model. The one-year incidence of postoperative epilepsy for patients with general anaesthesia and neuraxial anaesthesia were 0.41 and 0.32 per 1000 persons, respectively, and the corresponding RR was 1.27 (95%CI 1.15-1.41). The association between general anaesthesia and postoperative epilepsy was significant in men (RR = 1.22; 95%CI 1.06-1.40), women (RR = 1.33; 95%CI 1.15-1.55) and 20-39-year-old patients. The risk of postoperative epilepsy increased in patients with general anaesthesia who had co-existing medical conditions and postoperative complications.

A simulation impact evaluation of a cigarette excise tax increase on licit and illicit cigarette consumption and tax revenue in 36 European countries.

OBJECTIVES: To assess the impact of a simulated 10% tax-induced cigarette price increase on licit and illicit consumption and tax revenues in 36 European countries. METHODS: Employing panel data for licit and illicit cigarette consumption, fixed effects regression models were applied for different income clusters. RESULTS: Total cigarette consumption dropped by about 3.1% as a result of the simulated tax-induced price increase. Annual illicit cigarette consumption increased by 1.52%, (95% confidence interval: 0.21, 2.83), while annual licit cigarette consumption decreased by 4.61% (95% confidence interval: -6.51, -2.72) in the observed 36 European countries. With total consumption decreasing by about 8%, the Czech Republic, Latvia, Lithuania, Poland and Slovakia were affected the most by the price hike. More specifically, licit consumption in these countries decreased by 18.43% (95% confidence interval: -19.91, -16.95) while illicit use increased by 10.99% (95% confidence interval: 6.01, 15.96). Moreover, the overall annual tobacco tax revenue increased by US$14.69 billion in the simulation. CONCLUSION: Results of the study suggest that European policy makers continue to implement tobacco taxation policies to control smoking prevalence and national health care expenditures. At the same time, efforts to kerb contraband activities along EU Eastern borders should be intensified.

Risk and outcomes of fracture in peripheral arterial disease patients: two nationwide cohort studies.

Using national insurance claims data of Taiwan, we found that patients with peripheral arterial disease (PAD) had increased risk of fracture during the follow-up period of 2000-2013. History of PAD was also associated with adverse outcomes in hospitalized fracture patients. Prevention strategies were needed in this susceptible population. INTRODUCTION: Limited information was available on the association between PAD and fracture. The purpose of this study is to evaluate fracture risk and post-fracture outcomes in patients with PAD. METHODS: We identified 6647 adults aged ≥ 20 years with newly diagnosed PAD using the Taiwan National Health Insurance Research Database in 2000-2004. Comparison cohort consisted of 26,588 adults without PAD randomly selected with frequency matching in age and sex. Events of fracture were identified during the follow-up period from January 1, 2000 until December 31, 2013, to evaluate adjusted hazard ratios (HR) and 95% confidence interval (CI) of fracture associated with PAD. Another nested cohort study of 799,463 hospitalized fracture patients analyzed adjusted odds ratios (ORs) and 95% CIs of adverse events after fracture among patients with and without PAD in 2004-2013. RESULTS: Incidences of fracture in people with and without PAD were 22.1 and 15.5 per 1000 person-years, respectively (P < .0001). Compared with control, the adjusted HR of fracture was 1.59 (95% CI, 1.48-1.69) for PAD patients. In the nested cohort study, patients with PAD had higher post-fracture mortality (OR = 1.16; 95% CI, 1.09-1.25) and various complications. PAD patients also had comparatively higher medical expenditure (2691 vs. 2232 USD, P < .0001) and longer hospital stay (10.6 vs. 9.0 days, P < 0.0001) during fracture admission. CONCLUSIONS: Increased risk of fracture and post-fracture adverse outcomes were associated with PAD. This susceptible population needs care to prevent fracture and to minimize adverse outcomes after it occurs.

Treatment strategies for endometrial cancer: current practice and perspective.

PURPOSE OF REVIEW: Endometrial cancer incidence is increasing in North America and is a major cause of morbidity and mortality in women. We review recent literature published on treatment of endometrial cancer and highlight areas of active interest. RECENT FINDINGS: There has been movement toward minimal invasive surgery at diagnosis; lymph node staging remains controversial and continues to be investigated. Progress has been made to establish consensus on endometrial cancer risk classification to promote consistency for future trial design. Molecular characterization of endometrial cancer and its integration into clinicopathological profiling to develop predictive biomarkers for treatment selection are active areas of research. Optimal adjuvant treatment strategy in high-risk endometrial cancer remains to be defined with recognition of treatment-related toxicity. Despite encouraging results in drug development for treatment of advanced/recurrent endometrial cancer, no targeted therapies beyond hormonal therapy are approved. There is an urgent need for scientifically validated therapy with predictive biomarkers. SUMMARY: Our understanding of endometrial cancer has evolved through improvements in molecular biology, allowing improved definition of target-specific therapies. The precise role and sequence of conventional and targeted therapies, including immunotherapy, will require careful attention to the design of clinical trials with translational emphasis to allow the discovery, validation, and implementation of predictive biomarkers into clinical care.

The upper-limb volumetric changes in breast cancer survivors with axillary web syndrome.

Whether upper-limb swelling is associated with axillary web syndrome (AWS) is unknown. We recruited unilateral breast cancer (BC) patients who were scheduled for surgical intervention and lymph node dissection. The pre-operative assessment and post-operative assessment 3-4 weeks after surgery evaluated the upper-limb circumferential measurements, segmental limb volume, pain scores, grasp, shoulder range of motion (ROM), shoulder muscle power and quality-of-life scores. In the control group, the peri-elbow volume and upper-arm volume were significantly higher post-operatively than pre-operatively. In the AWS group, no significant difference was found. In comparison with the control group, the AWS group had significantly more pain, less active ROM in shoulder abduction and a lower upper-limb volume at 0-10 cm proximal to the lateral epicondyle. The incidence of lymphedema was 9.9% and was not associated with AWS. AWS is a common morbidity of lymph node dissection and causes significant pain and restricted shoulder abduction in the affected limb in BC survivors. This study is the first to investigate post-operative upper-limb volumetric changes in BC survivors with and without AWS. Our findings are of great value for the clinical effect of AWS in BC survivors, for patient education, and for developing diagnostic tools for detecting AWS.

Pre-operative serum albumin level substantially predicts post-operative morbidity and mortality among patients with colorectal cancer who undergo elective colectomy.

The quantitative relationship between serum albumin level and surgical outcomes has not been clearly established. This study included 3732 patients with colon cancer who underwent a potentially curative colectomy. Post-operative mortality and morbidity were analysed according to the patients' demographic data, pre-operative comorbidities, and tumour-related factors. Age, asthma, renal impairment, and albumin level were significantly associated with post-operative morbidity and mortality in the multivariate analyses. Logistic regression analysis revealed linear relationships of post-operative morbidity and mortality with albumin level. The morbidity and mortality rates decreased by 7.3% and 15.6%, respectively, for each 0.1 g/dL increase in albumin level. This finding remained significant in the hypoalbuminaemia subgroup but not in the normoalbuminaemia subgroup. That is, the morbidity and mortality rates significantly decreased by 8.7% and 17.7%, respectively (both P < 0.001), in the former group and decreased by 2.7% (P = 0.112) and 11.6% (P = 0.092), respectively, in the latter group. This study demonstrated that serum albumin level linearly predicted the post-operative morbidity and mortality among the colorectal cancer patients. Pre-operative serum albumin level may therefore be used as a continuous rather than a categorical marker of disease severity, especially among patients with hypoalbuminaemia.

Interaction between hepatic membrane type 1 matrix metalloproteinase and acireductone dioxygenase 1 regulates hepatitis C virus infection.

Membrane type 1 matrix metalloproteinase (MT1-MMP) binds to and regulates the function of tetraspanin-enriched microdomains. It also physically interacts with claudin-1 and acireductone dioxygenase 1 (ADI1), both associated with hepatitis C virus (HCV) cell entry. Here, we examined hepatic expression of MT1-MMP, ADI1 and claudin-1 as well as their physical interaction in relation to serum or intrahepatic HCV-RNA levels. A total of 104 liver biopsies obtained from chronic hepatitis C patients and 84 liver tissues obtained from noncancerous parts of surgically removed HCV-related hepatocellular carcinoma were analysed. Positive cytoplasmic ADI1 in liver biopsies was associated with higher serum HCV-RNA levels (P = 0.009). Positive MT1-MMP and ADI1 interaction assessed by co-immunoprecipitation was associated with lower tissue HCV-RNA levels (P = 0.009). Hepatic HCV-RNA levels were positively associated with ADI1 levels in the MT1-MMP and ADI1 co-immunoprecipitates (P = 0.030). Overexpression of MT1-MMP in Huh7.5 cells suppressed cell entry of HCV pseudoparticles as well as HCVcc infection. The suppression effect could be reversed by co-expression of ADI1 in a dose-dependent manner. In summary, clinical and cell-based experiments suggested that physical interaction between MT1-MMP and ADI1 led to suppression of HCV infection. This inhibitory effect could be reversed by ADI1 overexpression.

Characterization of residual tumours at the primary site in patients with a near pathological complete response after neoadjuvant chemoradiotherapy for oesophageal cancer.

BACKGROUND: A 'surgery as needed' strategy has been proposed for patients with oesophageal cancer who truly achieve a pathological complete response (pCR) following neoadjuvant chemoradiotherapy (nCRT). However, the ability to detect residual disease remains problematic. This study investigated the anatomical locations and pathological characteristics of residual cancer in patients with oesophageal squamous cell carcinoma (SCC) who achieved a near pCR following nCRT. METHODS: Patients with oesophageal SCC who achieved a near pCR after nCRT were eligible. Near pCR was defined as residual cancer in the resection specimen representing less than 10 per cent of the apparent original tumour area. RESULTS: Detailed histopathological reassessment of 76 consecutive patients (mean age 54·4 years) with a near pCR was undertaken. Some 32 patients (42 per cent) with a near pCR had no detectable mucosal lesions. Residual tumour was identified most frequently in the submucosal layer (54, 71 per cent), followed by the mucosa (44, 58 per cent), muscle layer (36, 47 per cent) and adventitia (22, 29 per cent) (P < 0·001). Among patients without ypT1a disease, increasing depth of tumour invasion correlated negatively with the likelihood of mucosal involvement. Of patients with ypT3 disease, 16 of 22 had no detectable cancer located in the mucosa, compared with six of 29 with ypT1b disease (P < 0·001). CONCLUSION: Better tools for predicting pCR are required before considering a 'surgery as needed' approach in the management of oesophageal cancer.