Transient changes in mismatch negativity after two sessions of electroconvulsive therapy for atypical psychosis: A case report.

Background: Cognitive abnormalities associated with electroconvulsive therapy (ECT) are limited to the first few days after treatment. Mismatch negativity (MMN) is an event-related potential that reflects an automatic auditory change detection process under nonattention conditions and cognitive function in psychotic disorders and may be trait- or state-dependent. This study aimed to report the changes in MMN and cognitive function after two ECT treatments in a female patient who underwent maintenance ECT for atypical psychosis. Case Presentation: A 67-year-old Japanese woman with atypical psychosis was admitted to our hospital for the maintenance of ECT. She received two ECT treatments. We measured her duration-MMN (MMN-D) at baseline, the day after two ECT treatments, and approximately 40 days after the two ECT treatments. After the two ECT treatments, the peak latency of the MMN on the following day was delayed compared with that before the first ECT treatment. Forty days after the two ECT treatments, the peak latency reverted to the baseline. The Brief Assessment of Cognition in Schizophrenia scores measured at the same time point also showed a similar temporary decrease in scores. Conclusion: Peak latency prolongation in MMN-D may reflect transient cognitive abnormalities after ECT. MMN can be useful to evaluate cognitive dysfunction, one of the adverse events of ECT. However, future studies are needed to examine the reproducibility and to examine the results in diseases other than atypical psychosis.

Rosai-Dorfman disease differentiated from a posterior mediastinal tumour: a case report.

Rosai-Dorfman disease presenting solely with intrathoracic lesions is exceptionally rare. Herein, we report the case of a 53-year-old man presenting with a posterior mediastinal tumour. Computed tomography revealed a 7-cm soft tissue shadow in the posterior mediastinum. Positron emission tomography-computed tomography demonstrated a high maximum standardized uptake value of 10.35 in the tumour, with no evidence of lymph node or other organ involvement. Serum marker levels were within the normal range. Thoracoscopic surgery was performed to obtain a biopsy for a definitive diagnosis and treatment planning. Postoperative histological findings revealed a diffuse infiltration of eosinophilic histiocytes, lymphocytes, and plasma cells. Immunohistochemical analysis indicated positivity for S-100 protein, oct-2, and cyclin D1 in these histiocytes. Consequently, the patient was diagnosed with Rosai-Dorfman disease and is currently asymptomatic, undergoing regular monitoring without treatment as an outpatient. The absence of characteristic findings, such as bilateral cervical lymphadenopathy, posed challenges in preoperative diagnosis.

Small sized centroblasts as poor prognostic factor in follicular lymphoma - Based on artificial intelligence analysis.

Histological assessment of centroblasts is an important evaluation in the diagnosis of follicular lymphoma, but there is substantial observer variation in assessment among hematopathologists. We aimed to perform quantitative morphological analysis of centroblasts in follicular lymphoma using new artificial intelligence technology in relation to the clinical prognosis. Hematoxylin and eosin slides of lesions were prepared from 36 cases of follicular lymphoma before initial chemotherapy. Cases were classified into three groups by clinical course after initial treatment. The 'excellent prognosis' group were without recurrence or progression of follicular lymphoma within 60 months, the 'poor prognosis' group were those that had relapse, exacerbation, or who died due to the follicular lymphoma within 60 months, and the 'indeterminate prognosis' group were those without recurrence or progression but before the passage of 60 months. We created whole slide images and image patches of hematoxylin and eosin sections for all cases. We designed an object detection model specialized for centroblasts by fine-tuning YOLOv5 and segmented all centroblasts in whole slide images. The morphological characteristics of centroblasts in relation to the clinical prognosis of follicular lymphoma were analyzed. Centroblasts in follicular lymphoma of the poor prognosis group were significantly smaller in nuclear size than those in follicular lymphoma of the excellent prognosis group in the following points: median of nuclear area (p = 0.013), long length (p = 0.042), short length (p = 0.007), nuclear area of top 10 % cells (p = 0.024) and short length of top 10 % cells (p = 0.020). Cases with a mean nuclear area of <55 µm2 had poorer event-free survival than those with a mean nuclear area of ≥55 µm2 (p < 0.0123). AI methodology is suggested to be able to surpass pathologist's observation in capturing morphological features. Small-sized centroblasts will likely become a new prognostic factor of follicular lymphoma.

Artificial Intelligence Detected the Relationship Between Nuclear Morphological Features and Molecular Abnormalities of Papillary Thyroid Carcinoma.

Papillary thyroid carcinoma (PTC) is the most common type of thyroid carcinoma and has characteristic nuclear features. Genetic abnormalities of PTC affect recent molecular target therapeutic strategy towards RET-altered cases, and they affect clinical prognosis and progression. However, there has been insufficient objective analysis of the correlation between genetic abnormalities and nuclear features. Using our newly developed methods, we studied the correlation between nuclear morphology and molecular abnormalities of PTC with the aim of predicting genetic abnormalities of PTC. We studied 72 cases of PTC and performed genetic analysis to detect BRAF p.V600E mutation and RET fusions. Nuclear features of PTC, such as nuclear grooves, pseudo-nuclear inclusions, and glassy nuclei, were also automatically detected by deep learning models. After analyzing the correlation between genetic abnormalities and nuclear features of PTC, logistic regression models could be used to predict gene abnormalities. Nuclear features were accurately detected with over 0.90 of AUCs in every class. The ratio of glassy nuclei to nuclear groove and the ratio of pseudo-nuclear inclusion to glassy nuclei were significantly higher in cases that were positive for RET fusions (p = 0.027, p = 0.043, respectively) than in cases that were negative for RET fusions. RET fusions were significantly predicted by glassy nuclei/nuclear grooves, pseudo-nuclear inclusions/glassy nuclei, and age (p = 0.023). Our deep learning models could accurately detect nuclear features. Genetic abnormalities had a correlation with nuclear features of PTC. Furthermore, our artificial intelligence model could significantly predict RET fusions of classic PTC.

Double Negativity of MRI-Detected and Pathologically-Diagnosed Extramural Venous Invasion is a Favorable Prognostic Factor for Rectal Cancer.

BACKGROUND: Extramural venous invasion (EMVI) is a prognostic factor in rectal cancer. There are two types: EMVI detected by magnetic resonance imaging (MRI) (mr-EMVI) and EMVI detected by pathology (p-EMVI). They have been separately evaluated, but they have not yet been concurrently evaluated. We therefore evaluate both mr-EMVI and p-EMVI in rectal cancer at the same time and clarify their association with prognosis. PATIENTS AND METHODS: Included were the 186 consecutive patients who underwent complete radical resection of tumors ≤ stage III at Wakayama Medical University Hospital, Japan, between 2010 and 2018. All underwent preoperative MRI examination, and were reassessed for EMVI by a radiologist. Surgically resected specimens were then reassessed for EMVI by a pathologist. We assessed the correlation between positivity of mr-EMVI and p-EMVI and prognosis, and the clinicopathological background behind them. RESULTS: Patients with double negativity for mr-EMVI and p-EMVI had better prognosis than patients with mr-EMVI or p-EMVI positivity (p < 0.0001). Positivity for mr-EMVI or p-EMVI was a poor independent prognostic factor in multivariate analysis. CONCLUSIONS: Combined analysis of mr-EMVI and p-EMVI may enable prediction of postoperative prognosis of rectal cancer. Patients with double negativity of mr-EMVI and p-EMVI had better prognosis than patients with some form of positivity. Stated differently, patients with positivity of mr-EMVI, p-EMVI, or both had a poorer prognosis than those with double negativity. Postoperative adjuvant chemotherapy may improve poor prognosis. Combined evaluation of mr-EMVI and p-EMVI may be used to predict clinical outcomes and may be an effective prognostic predictor of rectal cancer.

Thromboembolic complications during and after embolization of unruptured aneurysms: A chronological outcome in periprocedural thromboembolic events.

Background: Ischemic complications develop after elective coil embolization procedures at a certain rate. The prevention of these events has been a longstanding issue for many interventional neuroradiologists. This study aimed to clarify whether procedural ischemic events after unruptured aneurysm embolization decrease over time with perioperative anti-thromboembolic treatment or surgical experience. Methods: This study included patients with cerebral aneurysms in our institution between July 2012 and June 2020. Dual-antiplatelet therapy (DAPT) was performed (Phase 1). Thromboembolic events developed at a certain rate; thus, rivaroxaban was administered with single-antiplatelet therapy (SAPT) to improve thromboembolic results (Phase 2), showing better outcomes than in Phase 1. Subsequently, DAPT was administered again (Phase 3). Ischemic complications were evaluated in each phase or compared between the DAPT group and the direct oral anticoagulant (DOAC) with the clopidogrel (DOAC+SAPT) group. Results: Relatively, fewer symptomatic ischemic events were noted in Phase 2 or the DOAC+SAPT group, but the outcome was not better in Phase 3 than in Phase 2. Symptomatic complications were more common in Phase 3 than in Phases 1 and 2. Conclusion: Ischemic complications occurred at a certain rate after endovascular procedures for unruptured aneurysms. The incidence did not decrease over time; particularly, standard DAPT plus postoperative anti-thromboembolic medication did not adequately decrease complications in Phase 3 compared to Phases 1 and 2. Therefore, accumulated experience or a learning curve could not explain the results. DOAC administration might decrease the risk of these events, but further accumulation of evidence or prospective investigation is warranted.

HER2-Positive Metaplastic Breast Cancer with Resistance to Neoadjuvant Chemotherapy: Case Report.

Introduction: Metaplastic breast carcinoma (MBC) is a rare histologic subtype of breast carcinoma, which is usually negative for estrogen receptor, progesterone receptor, and HER2. HER2-positive MBC is therefore extremely rare. Most MBCs have poor response to chemotherapy. HER2-targeted neoadjuvant chemotherapy (NAC) is widely performed and has high efficacy in treating HER2-positive breast cancer. We report an atypical case of HER2-positive breast cancer that had poor response to NAC and was diagnosed with MBC after the surgery. Case Presentation: A 73-year-old woman noticed a mass in her right breast and visited our hospital. The mass was diagnosed as hormone receptor-negative, HER2-positive invasive ductal carcinoma, T2N0M0 stage IIA. She received HER2-targeted NAC comprising trastuzumab + pertuzumab + docetaxel. Despite three courses, we observed disease progression. The next NAC regimen was composed of two courses of epirubicin + cyclophosphamide, but the cancer continued to grow. She stopped receiving NAC and underwent a unilateral mastectomy and sentinel lymph node biopsy. Although the preoperative pathological result of core needle biopsy specimen showed invasive ductal carcinoma, the postoperative pathological result of the surgical specimen was MBC. Conclusion: In this case, when the patient had undergone three courses of trastuzumab + pertuzumab + docetaxel, it would have been appropriate to review the result of the core needle biopsy with pathologists or to perform vacuum-assisted breast biopsy. This case suggests the importance of considering the possibility of special histologic subtypes such as MBC when a tumor with the diagnosis of invasive ductal carcinoma is resistant to NAC.

E-learning system to improve the endoscopic diagnosis of early gastric cancer.

We developed three e-learning systems for endoscopists to acquire the necessary skills to improve the diagnosis of early gastric cancer (EGC) and demonstrated their usefulness using randomized controlled trials. The subjects of the three e-learning systems were "detection," "characterization," and "preoperative assessment." The contents of each e-learning system included "technique," "knowledge," and "obtaining experience." All e-learning systems proved useful for endoscopists to learn how to diagnose EGC. Lecture videos describing "the technique" and "the knowledge" can be beneficial. In addition, repeating 100 self-study cases allows learners to gain "experience" and improve their diagnostic skills further. Web-based e-learning systems have more advantages than other teaching methods because the number of participants is unlimited. Histopathological diagnosis is the gold standard for the diagnosis of gastric cancer. Therefore, we developed a comprehensive diagnostic algorithm to standardize the histopathological diagnosis of gastric cancer. Once we have successfully shown that this algorithm is helpful for the accurate histopathological diagnosis of cancer, we will complete a series of e-learning systems designed to assess EGC accurately.

RS3PE Syndrome with Subsequent PMR Caused by Long-Term DPP-4 Inhibitor Use.

Remitting seronegative symmetrical synovitis with pitting oedema (RS3PE) syndrome has been reported in patients treated with dipeptidyl peptidase-4 inhibitors (DPP-4i). We experienced a case of RS3PE syndrome in a 73-year-old man with a history of type 2 diabetes, who developed RS3PE as a side effect of vildagliptin. Further to this, the patient developed polymyalgia rheumatica (PMR), the first such case associated with long-term DPP-4i use. LEARNING POINTS: RS3PE syndrome and PMR are rare diseases that cause painful extremities in adults. We need to know if it occurs by DPP-4i.RS3PE syndrome and PMR can be complicated with malignancy or giant cell arteritis. However, we must rule out side effects of drugs at first from the standpoint of medical resources.

Appropriate treatment within 13 hours after onset may improve outcome in patients with high-grade aneurysmal subarachnoid hemorrhage.

OBJECTIVE: This retrospective study evaluated whether earlier timing of appropriate treatment of high-grade aneurysmal subarachnoid hemorrhage (aSAH), defined as management of ruptured intracranial aneurysm (RIA) combined with required additional surgical measures for control of increased intracranial pressure (ICP), is associated with more favorable outcomes. METHODS: The study cohort comprised 253 patients with high-grade aSAH. Modified Rankin Scale score of 0-3 at 3-month follow-up after the ictus was considered as favorable outcome. RESULTS: Appropriate treatment of aSAH was completed in 205 patients (81 %), and included clipping or coiling of RIA without (64 cases) and with (141 cases) additional surgical measures for control of increased ICP (evacuation of intracranial hematoma, decompressive craniotomy, and/or cerebrospinal fluid drainage). Favorable outcome was noted significantly more often if appropriate treatment was completed within 13 h after aSAH than between 13 and 72 h (37 % vs. 17 %; adjusted P = 0.0475), which was confirmed by evaluation in the multivariate model along with other prognostic factors. Subgroup analysis revealed that completion of the appropriate treatment within 13 h was associated with more favorable outcome in those patients, who underwent management of RIA in combination with additional surgical measures for control of increased ICP (P = 0.0023), and in those, who felt into poor outcome predicting group (P = 0.0046). CONCLUSIONS: Appropriate treatment of high-grade aSAH with management of RIA in combination with required additional surgical measures for control of increased ICP, may be associated with more favorable outcomes if completed within 13 h after the ictus.

Feasibility of methotrexate discontinuation following tocilizumab and methotrexate combination therapy in patients with long-standing and advanced rheumatoid arthritis: a 3-year observational cohort study.

OBJECTIVES: Methotrexate (MTX) is associated with extensive side effects, including myelosuppression, interstitial pneumonia, and infection. It is, therefore, critical to establish whether its administration is required after achieving remission with tocilizumab (TCZ) and MTX combination therapy in patients with rheumatoid arthritis (RA). Therefore, the aim of this multicenter, observational, cohort study was to evaluate the feasibility of MTX discontinuation for the safety of these patients. METHODS: Patients with RA were administered TCZ, with or without MTX, for 3 years; those who received TCZ+MTX combination therapy were selected. After remission was achieved, MTX was discontinued without flare development in one group (discontinued [DISC] group, n = 33) and continued without flare development in another group (maintain [MAIN] group, n = 37). The clinical efficacy of TCZ+MTX therapy, patient background characteristics, and adverse events were compared between groups. RESULTS: The disease activity score in 28 joints-erythrocyte sedimentation rate (DAS28-ESR) at 3, 6, and 9 months was significantly lower in the DISC group (P < .05, P < .01, and P < .01, respectively). Further, the DAS28-ESR remission rate at 6 and 9 months and Boolean remission rate at 6 months were significantly higher in the DISC group (P < .01 for all). Disease duration was significantly longer in the DISC group (P < .05). Furthermore, the number of patients with stage 4 RA was significantly higher in the DISC group (P < .01). CONCLUSIONS: Once remission was achieved, MTX was discontinued in patients who responded favorably to TCZ+MTX therapy, despite the prolonged disease duration and stage progression.

Targeted Next-Generation Sequencing of Flat Urothelial Lesions Reveals Putative Pathobiological Pathways, Potential Biomarkers, and Rational Therapeutic Targets.

Flat urothelial lesions are controversial diagnostic and prognostic urologic entities whose importance relies mainly on their ability to progress to muscle-invasive tumors via urothelial carcinoma in situ (CIS). However, the carcinogenetic progression of preneoplastic flat urothelial lesions is not well established. Moreover, predictive biomarkers and therapeutic targets of the highly recurrent and aggressive urothelial CIS lesion are lacking. Using a targeted next-generation sequencing (NGS) panel of 17 genes directly involved in bladder cancer pathogenesis, we investigated alterations of genes and pathways with clinical and carcinogenic implications on 119 samples of flat urothelium, including normal urothelium (n = 7), reactive atypia (n = 10), atypia of unknown significance ( n = 34), dysplasia ( n = 23), and CIS (n = 45). The majority of the flat lesions were tumor-associated but grossly/microscopically or temporally separated from the main tumor. Mutations were compared across flat lesions and concerning the concomitant urothelial tumor. Associations between genomic mutations and recurrence after intravesical bacillus Calmette-Guerin treatment were estimated with Cox regression analysis. TERT promoter mutations were highly prevalent in intraurothelial lesions but not in the normal or reactive urothelium, suggesting that it is a critical driver mutation in urothelial tumorigenesis. We found that synchronous atypia of unknown significance-dysplasia-CIS lesions without concomitant papillary urothelial carcinomas had a similar genomic profile that differed from atypia of unknown significance-dysplasia lesions associated with papillary urothelial carcinomas, which harbored significantly more FGFR3, ARID1A, and PIK3CA mutations. KRAS G12C and ERBB2 S310F/Y mutations were exclusively detected in CIS and were associated with recurrence after bacillus Calmette-Guerin treatment (P = .0006 and P = .01, respectively). This targeted NGS study revealed critical mutations involved in the carcinogenetic progression of flat lesions with putative pathobiological pathways. Importantly, KRAS G12C and ERBB2 S310F/Y mutations were identified as potential prognostic and therapeutic biomarkers for urothelial carcinoma.

Use of Artificial Intelligence for the Interpretable Prediction of the Pathologic Diagnosis and Molecular Abnormalities of Flat Urothelial Lesions.

Flat urothelial lesions are important because of their potential for carcinogenesis and development into invasive urothelial carcinomas. However, it is difficult for pathologists to detect early flat urothelial changes and accurately diagnose flat urothelial lesions. To predict the pathologic diagnosis and molecular abnormalities of flat urothelial lesions from pathologic images, artificial intelligence with an interpretable method was used. Next-generation sequencing on 110 hematoxylin and eosin-stained slides of normal urothelium and flat urothelial lesions, including atypical urothelium, dysplasia, and carcinoma in situ, detected 17 types of molecular abnormalities. To generate an interpretable prediction, a new method for segmenting urothelium and a new pathologic criteria-based artificial intelligence (PCB-AI) model was developed. κ Statistics and accuracy measurements were used to evaluate the ability of the model to predict the pathologic diagnosis. The likelihood ratio test was performed to evaluate the logistic regression models for predicting molecular abnormalities. The diagnostic prediction of the PCB-AI model was almost in perfect agreement with the pathologists' diagnoses (weighted κ = 0.98). PCB-AI significantly predicted some molecular abnormalities in an interpretable manner, including abnormalities of TP53 (P = 0.02), RB1 (P = 0.04), and ERCC2 (P = 0.04). Thus, this study developed a new method of obtaining accurate urothelial segmentation, interpretable prediction of pathologic diagnosis, and interpretable prediction of molecular abnormalities.

Pathologic Image Classification of Flat Urothelial Lesions Using Pathologic Criteria-Based Deep Learning.

OBJECTIVES: Pathologic diagnosis of flat urothelial lesions is subject to high interobserver variability. We expected that deep learning could improve the accuracy and consistency of such pathologic diagnosis, although the learning process is a black box. We therefore propose a new approach for pathologic image classification incorporating the diagnostic process of the pathologist into a deep learning method. METHODS: A total of 267 H&E-stained slides of normal urothelium and urothelial lesions from 127 cases were examined. Six independent convolutional neural networks were trained to classify pathologic images according to six pathologic criteria. We then used these networks in the main training for the final diagnosis. RESULTS: Compared with conventional manual analysis, our method significantly improved the classification accuracy of images of flat urothelial lesions. The automated classification showed almost perfect agreement (weighted κ = 0.98) with the consensus reading. In addition, our approach provides the advantages of reliable diagnosis corresponding to histologic interpretation. CONCLUSIONS: We used deep learning to establish an automated subtype classifier for flat urothelial lesions that successfully combines traditional morphologic approaches and complex deep learning to achieve a learning mechanism that seems plausible to the pathologist.

Carotid endarterectomy with stent removal for recurring in-stent restenosis: A case report and literature review.

Background: Percutaneous transcatheter angioplasty (PTA) and carotid artery stenting (CAS) are often performed repeatedly for in-stent restenosis (ISR) after CAS. Only a few reports describe the treatment for repeated ISR. Furthermore, only a few reports describe carotid endarterectomy (CEA) after CAS; thus, the evidence for this procedure is insufficient. Case Description: Herein, we describe a case in which CEA with stent removal was performed in a patient with repeated ISR after CAS. A 78-year-old man presented with dysarthria and slight left limb weakness. CAS was performed for the right internal carotid artery stenosis. ISR occurred again and PTA and stenting were performed. After the second CAS, ISR occurred again. CEA with stent removal was performed. After the CEA with stent removal, the patient experienced no restenosis or other complications. Conclusion: CEA with stent removal can be a good option for treating repeated ISR after CAS.

Use of n-butyl-2-cyanoacrylate for microvascular decompression in a Jehovah's witness patient.

OBJECTIVE: We report the application of n-butyl-2-cyanoacrylate (n-BCA) in microvascular decompression (MVD) surgery for a Jehovah's Witness patient. To our best knowledge, this is the first case wherein n-BCA has been employed as an adhesive to the offending artery. CASE PRESENTATION: A 55-year-old female Jehovah's Witness patient was suffering from serious right hemifacial spasm. Although MVD surgery was needed, the patient resisted any curative medical treatment involving the application of whole blood products, including fibrin glue. Thus, we proposed several choices using artificial materials, including n-BCA as an adhesive, and received informed consent from the patient. RESULT: MVD was performed on the dolichoectatic right vertebral artery and right posterior inferior cerebellar artery. The abnormal vessel response disappeared during the procedure and transposition using n-BCA of the concerned vessels was successful. The patient experienced a favorable postoperative clinical course and has been free from the spasm for a year. No abnormal findings were detected in the radiological examination during the follow-up period. CONCLUSION: Although careful follow-up is mandatory, n-BCA is a possible alternative option in MVD surgery.

Problematic Internet use and daily difficulties among adolescents with school refusal behaviors: An observational cross-sectional analytical study.

ABSTRACT: Problematic Internet use (PIU) is common and likely to coexist with mental health problems among adolescents with school refusal behavior. To date, no study has revealed to what extent PIU relates to the daily burden compared with other mental health problems. This study has examined the association between daily difficulties and PIU among adolescents with school refusal behaviors.This cross-sectional study involved all first-visit patients, regardless of diagnosis, aged 10 to 18 years at 2 child/adolescent psychiatric outpatient clinics in Yokohama City, Japan, from April 2016 to March 2018. The Questionnaire-Children with Difficulties (QCD) were obtained from parents. Simultaneously, the severity of PIU was evaluated using the Internet Addiction Test and depressive and anxiety symptoms were evaluated using the Patient Health Questionnaire-9 and General Anxiety Disorder-7 scale in the 2 weeks before the first-visit. From 684 first-visit patients, 227 with school refusal behaviors were enrolled in the study.PIU was observed in 40% of adolescents with school refusal behaviors. The QCD scores among patients with PIU were significantly lower than those in patients without PIU. Linear regression analysis revealed relationships between PIU and lower QCD scores throughout the day (except at night) and the total score of the day, after controlling for confounders such as depressive and anxiety symptoms.In conclusion, among adolescents with school refusal behaviors, PIU may affect their parent-assessed daily difficulties particularly experienced throughout the day.

Prognostic value of CD155/TIGIT expression in patients with colorectal cancer.

INTRODUCTION: The interaction of CD155 with its ligand, the T cell immunoreceptor with Ig and ITIM domains (TIGIT), is being studied owing to its potential to act as a target in the treatment of various solid tumors. However, the relationship between CD155 and TIGIT in colorectal cancer (CRC) prognosis is not known. We hypothesized that the TIGIT-CD155 pathway suppresses the attack of T cells on tumors, thereby affecting CRC prognosis. METHODS: We examined the expression of CD155 and TIGIT using immunohistochemical staining in 100 consecutive patients with CRC who underwent complete resection of ≤Stage III tumors at Wakayama Medical University Hospital between January and December 2013. We assessed the correlation between CD155 and TIGIT expressions and prognosis as well as the clinicopathological background of CD155 and TIGIT. RESULTS: Patients with high CD155 and TIGIT expressions showed worse prognosis than those with other levels of expression (p = 0.026). In multivariate analysis that also included the existing prognostic markers, high CD155 and TIGIT expressions were identified as independent poor prognostic factors. CONCLUSIONS: The interaction between CD155 and TIGIT possibly plays an important role in the immunological mechanism of CRC. Therefore, it may be possible to effectively predict the postoperative prognosis of CRC by evaluating the combined expression of CD155 and TIGIT. The study findings suggest that CD155 and TIGIT can predict clinical outcomes, thereby contributing to the personalized care of CRC.