Immune checkpoint status and oncogenic mutation profiling of rectal cancer after neoadjuvant chemotherapy (KSCC1301-A2).

Aim: Immune checkpoint inhibitors (ICIs) are less effective in mismatch repair (MMR)-proficient (pMMR) colorectal cancers (CRCs) than in MMR-deficient CRCs. Here, we investigated changes in the tumor microenvironment after neoadjuvant chemotherapy (NAC) without radiotherapy in locally advanced rectal cancer (LARC) and the potential of ICIs as therapeutic agents for pMMR CRCs. Methods: This was an ad hoc analysis of a KSCC1301 randomized phase II trial in which patients with untreated resectable LARC were randomly assigned to receive S-1 and oxaliplatin or folinic acid, 5-fluorouracil, and oxaliplatin as NAC. Forty-nine patients were studied in this ad hoc analysis. As a reference cohort, we assessed 25 rectal cancer patients who underwent surgery without NAC outside the randomized trial. Immune checkpoint molecules (ICMs; PD-1, PD-L1, CTLA-4, LAG3), tumor-infiltrating lymphocytes (TILs; CD8, FOXP3), and other related proteins were evaluated by immunohistochemistry. Next-generation sequencing (NGS) using Oncomine™ Comprehensive Assay version 3 was conducted in 23 patients. Results: The expression levels of PD-1, CTLA-4, and LAG3 in the NAC group were significantly higher than in reference patients (p < 0.001). Additionally, the infiltration of CD8+ and FOXP3+ T cells, and the CD8/FOXP3 ratio were significantly higher in the NAC group than in reference patients (p < 0.0001). NGS analysis revealed no specific gene alteration related to TILs or ICMs. Conclusion: We demonstrated changes in the tumor immune microenvironment after NAC in pMMR rectal cancer. NAC was associated with increased expression of ICMs and TILs. Rectal cancer could be susceptible to combined immunotherapy with chemotherapy.

[Chemotherapy for Unresectable Advanced, Metastatic or Recurrent Colorectal Cancer].

Colorectal cancer(CRC)is one of the most commonly diagnosed cancers worldwide. Unresectable advanced, metastatic or recurrent CRC(mCRC)remains incurable for most patients. Systemic chemotherapy is standard treatment for patients with mCRC. The goals of systemic chemotherapy include prolonging survival by stopping cancer progression and palliation. In recent years, advances in the treatment of mCRC have enabled personalized care based on the tumor's molecular profile with improved outcomes for some subtypes. Targeted biologic therapies and immune checkpoint inhibitors have changed the approach to management of uncommon molecularly defined subsets of mCRC. The development of chemotherapy using cytotoxic drugs, biologic monoclonal antibodies, and immune checkpoint inhibitors has prolonged median overall survival up to approximately 30 months. In this report, we describe the evolution of systemic chemotherapy for mCRC, recent advances in standard treatment, and future prospects for the treatment of mCRC.

Three-dimensional imaging of intramural perineural invasion in colorectal cancer: Three-dimensional reconstruction approach with multiple immunohistochemically stained sections.

Perineural invasion (PNI) at Auerbach's plexus in colorectal cancer (CRC), known as intramural PNI, is associated with adverse prognostic outcomes. This study aimed to characterize the three-dimensional (3D) architecture of CRC with intramural PNI and to evaluate the morphological features of tumor invasion around nerve tissue. Serial tissue sections from two cases of CRC were stained with cytokeratin AE1/AE3 and an anti-S-100 protein antibody. 3D models were reconstructed by scanning the virtual slides. In one case, intramural PNI was observed at the horizontal invasive front. The 3D reconstruction model showed tumor cells that appeared to infiltrate along the nervous meshwork, the structure of which was preserved. In the other case, intramural PNI was observed both at and behind the horizontal invasive front, and the 3D reconstruction model showed that the tumor cells appeared to be involved with nerve cells at the focal part of the horizontal invasive front. However, the nervous meshwork structure was not well identified in cancer-involved areas. This is the first study to characterize the 3D structure of tumor invasion around nerve tissue in CRC, demonstrating the morphological features of intramural PNI in CRC.

Cytolytic activity score as a biomarker for antitumor immunity and clinical outcome in patients with gastric cancer.

BACKGROUND: A simple measure of immune cytolytic activity (CYT) base on mRNA expression levels of two genes, GZMA and PRF1, was recently reported. Here, we aimed to evaluate the CYT score's potential as a measure of antitumor immunity and predictor of clinical outcome in gastric cancer (GC) patients. MATERIALS AND METHODS: We evaluated the correlations between tumor-infiltrating immune cells and the CYT score in 238 GC samples from The Cancer Genome Atlas (TCGA). Next, we investigated CYT score associations with molecular subtypes, somatic mutation load, and immune checkpoint molecules in GC samples from TCGA and Asian Cancer Research Group (ACRG). Moreover, we evaluated the clinical significance of the CYT score calculated by reverse transcription (RT)-quantitative PCR (qPCR) data in 123 GC samples and the association of the CYT score with the response to anti-PD-1 therapy in 7 GC samples from Kyushu University Hospital. RESULTS: The CYT score positively correlated with the proportions of tumor-infiltrating CD8+ T cells and macrophages and negatively correlated with the proportion of regulatory T cells in GC tissues. A high CYT score was associated with common immune checkpoint molecules, a high mutation, the Epstein-Barr virus subtype, and the microsatellite instability subtype in GC. Moreover, a low CYT score was a poor prognosis factor in patients with GC. Finally, the CYT score was higher in a responder to anti-PD-1 therapy compared to nonresponders. CONCLUSION: The CYT score reflects antitumor immunity and predicts clinical outcome in GC patients.

Histological categorisation of the desmoplastic reaction is a predictor of patient prognosis in oesophageal squamous cell carcinoma.

AIMS: Histological categorisation of the desmoplastic reaction (DR) is an independent prognostic factor in colorectal cancer. However, it is unknown whether DR categorisation is predictive of oesophageal squamous cell carcinoma (OSCC) outcomes. This study aimed to evaluate the prognostic value of DR categorisation in OSCC patients. METHODS AND RESULTS: Data were collected from 118 patients with OSCC who underwent a curative oesophagectomy with T2 or deeper wall invasion. The DR in each tumour was classified as mature, intermediate or immature based on the presence or absence of keloid-like collagen and myxoid stroma. We identified 49 mature DR tumours, 41 intermediate DR tumours and 28 immature DR tumours. The 5-year overall survival (OS) rate was highest in the mature DR group (42.8%), followed by the intermediate DR group (25.0%) and the immature DR group (19.9%) (P = 0.022, log-rank test; P = 0.006, log-rank trend test). The 5-year disease-specific survival (DSS) rate was also highest in the mature DR group (48.5%), followed by the intermediate DR group (30.8%) and the immature DR group (26.8%) (P = 0.031, log-rank test; P = 0.010, log-rank trend test, respectively). Multivariate analysis revealed that an immature DR was an independent poor prognostic factor of OS and DSS (P = 0.002 and P = 0.004). CONCLUSIONS: DR categorisation of OSCC stroma following oesophagectomy is a useful diagnostic tool and an independent prognostic marker.

Late recurrence of cancer stem cell-positive colorectal cancer liver metastases after 15 years.

No cases of late recurrence of colorectal cancer liver metastasis (CRLM) over 10 years have been reported in the literature. A 72-year-old woman had a surgical history of sigmoid colectomy and partial hepatic resections for sigmoid colon cancer and multiple liver metastases 15 years previously. The patient had been postoperatively treated with chemotherapy for 6 months and was observed regularly with no recurrence. Computed tomography (CT) performed due to high carcinoembryonic antigen (CEA) revealed a tumor of 70 mm in diameter at the anterior segment of the liver and a 6-mm nodule at the left lateral segment. There was no other malignant finding. We performed central bisegmentectomy and partial resection of the liver. Pathological findings showed the tumors to be well to moderately differentiated adenocarcinoma, and positive cytokeratin 20 (CK20) and caudal-type homeobox transcription factor 2 (CDX2) expression with negative expression of cytokeratin 7 (CK7). In addition, the tumors showed cluster of differentiation 44 (CD44) and 133 (CD133) positive signified cancer stem cell immunohistochemically. The postoperative diagnosis was recurrence of hepatic metastasis of sigmoid colon cancer. We report a rare case of late recurrence of CRLM more than 15 years after the primary diagnosis.

Quadruple gastrointestinal cancer with discordance of mismatch repair protein deficiency and microsatellite instability suggesting Lynch syndrome.

A 65-year-old woman with prior personal and family histories of cancer was admitted to our hospital for quadruple cancer. Preoperative endoscopy revealed a type 0-II gastric cancer (GC; gastric body), advanced type-II colon cancer (ascending colon), and early-stage recto-sigmoid colon cancers. We diagnosed her with Lynch syndrome (LS) per Amsterdam criteria, and performed distal gastrectomy, ileocecal resection and high anterior resection. Her pathological diagnoses were GC: well-to-poorly differentiated adenocarcinoma (AD, por2 > tub2) with signet-ring cells, ypT1b SM2; ascending colon cancer: AD with focal mucin products (tub2 > muc), SS; sigmoid colon cancer: AD (tub1), M; recto-sigmoid cancer: AD (tub1 > tub2), SM. Immunohistochemical tests revealed that all cancers lacked the MLH1/PMS2 protein. However, the three colon cancers were found to have high microsatellite instability (MSI); the GC was microsatellite stable (MSS). No recurrence or other cancers were observed for 30 months after surgery without adjuvant chemotherapy. As patients with LS may also develop MSS cancers, we should check for MSI in all LS cancers for proper treatment.

Gastric glomus tumor with a preoperative diagnosis by endoscopic ultrasonography-guided fine needle aspiration: a case report.

A gastric glomus tumor (GGT) is a rare gastric submucosal tumor that can become malignant. A preoperative diagnosis would allow for a more informed decision regarding the treatment strategy. We present the case of an asymptomatic man with a GGT that was diagnosed during a preoperative examination. Upper gastrointestinal endoscopy was performed in a 64-year-old man and revealed a submucosal tumor at the lesser curvature of the antrum of the stomach. Endoscopic ultrasonography showed a 12-mm-sized hypoechoic tumor in the second and third layers of the stomach wall. A histologic diagnosis of GGT was made using endoscopic ultrasonography-guided fine needle aspiration (EUS-FNA). Abdominal contrast-enhanced computed tomography was performed, but the identification of the tumor was difficult owing to poor enhancement. The gradual growth of the tumor made it necessary to perform an operation. Laparoscopy and endoscopy cooperative surgery was performed without any complications. The tumor cells were immunohistochemically positive for alpha-smooth muscle actin, h-caldesmon, and collagen type IV but were negative for desmin, discovered on GIST-1, S-100 protein, cluster of differentiation 34, epithelial membrane antigen, and cytokeratin AE1/AE3. The final diagnosis was identical to the preoperative diagnosis made using EUS-FNA. EUS-FNA is a useful method for the preoperative diagnosis of small submucosal tumors, including GGTs.

Radiomics Texture Analysis for the Identification of Colorectal Liver Metastases Sensitive to First-Line Oxaliplatin-Based Chemotherapy.

OBJECTIVE: The aim of this study was to develop a radiomics-based prediction model for the response of colorectal liver metastases to oxaliplatin-based chemotherapy. METHODS: Forty-two consecutive patients treated with oxaliplatin-based first-line chemotherapy for colorectal liver metastasis at our institution from August 2013 to October 2019 were enrolled in this retrospective study. Overall, 126 liver metastases were chronologically divided into the training (n = 94) and validation (n = 32) cohorts. Regions of interest were manually segmented, and the best response to chemotherapy was decided based on Response Evaluation Criteria in Solid Tumors (RECIST). Patients who achieved clinical complete and partial response according to RECIST were defined as good responders. Radiomics features were extracted from the pretreatment enhanced computed tomography scans, and a radiomics score was calculated using the least absolute shrinkage and selection operator regression model in a trial cohort. RESULTS: The radiomics score significantly discriminated good responders in both the trial (area under the curve [AUC] 0.8512, 95% confidence interval [CI] 0.7719-0.9305; p < 0.0001) and validation (AUC 0.7792, 95% CI 0.6176-0.9407; p < 0.0001) cohorts. Multivariate analysis revealed that high radiomics scores greater than - 0.06 (odds ratio [OR] 23.803, 95% CI 8.432-80.432; p < 0.0001), clinical non-T4 (OR 6.054, 95% CI 2.164-18.394; p = 0.0005), and metachronous disease (OR 11.787, 95% CI 2.333-70.833; p = 0.0025) were independently associated with good response. CONCLUSIONS: Radiomics signatures may be a potential biomarker for the early prediction of chemosensitivity in colorectal liver metastases. This approach may support the treatment strategy for colorectal liver metastasis.

Histomorphological investigation of intrahepatic connective tissue for surgical anatomy based on modern computer imaging analysis.

BACKGROUND/PURPOSE: Computer-assisted tissue imaging and analytical techniques were used to clarify the histomorphological structure of hepatic connective tissue as a practical guide for surgeons. METHODS: Approximately 5000 histological slides were prepared from liver specimens of five autopsied patients. Three-dimensional (3D) reconstruction was performed and subjected to computer imaging analysis. Scanning electron microscopy was also performed on the liver specimens. RESULTS: The 3D reconstructed images revealed the running form of the vasculature and the relationship between the hepatic lobule and connective tissue. The hepatic capsule or portal pedicle was consistently located at the periphery of the hepatic lobules. An artificial intelligence random forest approach clearly segmented hepatic cells, type I collagen (CF), type III collagen (RF), and other cells. The hepatic lobule, portal region, and hepatic capsule were significantly distinguished based on CF and RF occupancy. The capsule directly covering the liver lobule with an RF concentration up to 87% was provisionally named the proper hepatic capsule. The existence of a proper hepatic ligament with distinct occupation rates of CF and RF was also suggested. CONCLUSIONS: The identified proper hepatic capsule and ligament can be important markers for demarcating the dissecting layer during surgical procedures.

A rare case of esophageal adenocarcinoma with urinary bladder metastasis.

A 75-year-old man was admitted to our hospital for treatment of esophageal cancer (EC) in March 2017. Esophagogastroduodenoscopy revealed Barrett's esophagus and superficial, distal EC (type 0-IIc). Tumor biopsy showed esophageal adenocarcinoma. Computed tomography revealed no lymph node metastasis but did reveal a 19-mm tumor on the right side of the urinary bladder. Bladder cancer (BC) was also suspected, and the patient underwent endoscopic submucosal dissection for EC and transurethral resection of the bladder tumor. The pathological diagnosis of EC was moderately to poorly differentiated adenocarcinoma (tub2), pT1b (SM), ly0, v0. The pathological horizontal margin was negative and the vertical margin was positive. Additional esophagectomy and lymph node dissection were indicated for curability. Esophagectomy was difficult because the patient had severe cardiovascular disease, so follow-up observation was adopted. BC was classified as urothelial carcinoma Ta, ly0, v0. After 32 months, multiple tumors were found in the bladder, and BC recurrence was suspected. Transurethral resection of the bladder was performed again for seven tumors, and pathological diagnosis was poorly differentiated adenocarcinoma (tub2). The immunohistochemical features matched those of EC. We diagnosed EC metastasis in the urinary bladder. Bladder adenocarcinoma is difficult to distinguish from metastasis from other organs, especially the upper gastrointestinal tract, and cytomorphological features and appropriate clinical history are required.

Obstructive rectal endometriosis treated by robot-assisted laparoscopic surgery: a case report.

BACKGROUND: Rectal endometriosis is a rare disease. A definitive diagnosis prior to surgery is often difficult. We encountered a patient with rectal sub-obstructive endometriosis that was treated by robot-assisted laparoscopic low anterior resection. CASE PRESENTATION: A 43-year-old woman visited our hospital with suspected stenosis caused by upper rectal cancer. She had a 2-year history of constipation. We were unable to confirm the diagnosis through detailed examinations, including laparoscopy. Robot-assisted laparoscopic low anterior resection with D3 lymph node dissection was performed for both diagnosis and treatment. The postoperative specimen showed a submucosal tumor. The pathological examination confirmed rectal endometriosis. CONCLUSIONS: We herein describe a rare case of obstructive rectal endometriosis that we were unable to diagnose preoperatively. Robotic surgery was useful in this case, which involved extensive pelvic adhesion.

Pleuropulmonary Paragonimiasis with Multiple Nodules in the Pleura.

An asymptomatic 47-year-old woman was admitted with pleural effusion and pulmonary infiltrates 1 month after ingesting raw wild boar and deer meat. Both her blood and pleural fluid were eosinophilic. Thoracoscopy revealed multiple nodules of the pleura, and biopsy samples of the nodules showed necrosis with epithelioid cell granulomas. An enzyme-linked immunosorbent assay was positive for antibodies against Paragonimus westermani, and the patient was successfully treated with praziquantel. This is the first reported case of pulmonary or pleuropulmonary paragonimiasis where several pleural nodules were observed. The detection of pleural nodules on thoracoscopy can contribute to the prompt and accurate diagnosis of paragonimiasis.

Dimeric pyrrolidinoindoline-type alkaloids with melanogenesis inhibitory activity in flower buds of Chimonanthus praecox.

A methanol extract of the flower buds of Chimonanthus praecox (L.) Link (Calycanthaceae) demonstrated inhibitory effects on melanogenesis in theophylline-stimulated murine B16 melanoma 4A5 cells. From the extract, five dimeric pyrrolidinoindoline alkaloids and four sesquiterpenes were isolated, together with 16 known compounds. Among them, (-)-chimonanthine (1, IC50 = 0.93 µM), (-)-folicanthine (2, 1.4 µM), and (-)-calycanthidine (3, 1.8 µM) showed potent inhibitory effects without notable cytotoxicity at the effective concentrations. The most potent alkaloid (1) inhibited both tyrosinase and tyrosine-related protein-1 mRNA expressions, to which the melanogenesis inhibitory activity would be ascribable.

Two complementary enzymes for threonylation of tRNA in crenarchaeota: crystal structure of Aeropyrum pernix threonyl-tRNA synthetase lacking a cis-editing domain.

In protein synthesis, threonyl-tRNA synthetase (ThrRS) must recognize threonine (Thr) from the 20 kinds of amino acids and the cognate tRNA(Thr) from different tRNAs in order to generate Thr-tRNA(Thr). In general, an organism possesses one kind of gene corresponding to ThrRS. However, it has been recently found that some organisms have two different genes for ThrRS in the genome, suggesting that their proteins ThrRS-1 and ThrRS-2 function separately and complement each other in the threonylation of tRNA(Thr), one for catalysis and the other for trans-editing of misacylated Ser-tRNA(Thr). In order to clarify their three-dimensional structures, we performed X-ray analyses of two putatively assigned ThrRSs from Aeropyrum pernix (ApThrRS-1 and ApThrRS-2). These proteins were overexpressed in Escherichia coli, purified, and crystallized. The crystal structure of ApThrRS-1 has been successfully determined at 2.3 A resolution. ApThrRS-1 is a dimeric enzyme composed of two identical subunits, each containing two domains for the catalytic reaction and for anticodon binding. The essential editing domain is completely missing as expected. These structural features reveal that ThrRS-1 catalyzes only the aminoacylation of the cognate tRNA, suggesting the necessity of the second enzyme ThrRS-2 for trans-editing. Since the N-terminal sequence of ApThrRS-2 is similar to the sequence of the editing domain of ThrRS from Pyrococcus abyssi, ApThrRS-2 has been expected to catalyze deaminoacylation of a misacylated serine moiety at the CCA terminus.

Crystallization and preliminary crystallographic studies of putative threonyl-tRNA synthetases from Aeropyrum pernix and Sulfolobus tokodaii.

Threonyl-tRNA synthetase (ThrRS) plays an essential role in protein synthesis by catalyzing the aminoacylation of tRNA(Thr) and editing misacylation. ThrRS generally contains an N-terminal editing domain, a catalytic domain and an anticodon-binding domain. The sequences of the editing domain in ThrRSs from archaea differ from those in bacteria and eukaryotes. Furthermore, several creanarchaea including Aeropyrum pernix K1 and Sulfolobus tokodaii strain 7 contain two genes encoding either the catalytic or the editing domain of ThrRS. To reveal the structural basis for this evolutionary divergence, the two types of ThrRS from the crenarchaea A. pernix and S. tokodaii have been overexpressed in Eschericha coli, purified and crystallized by the hanging-drop vapour-diffusion method. Diffraction data were collected and the structure of a selenomethionine-labelled A. pernix type-1 ThrRS crystal has been solved using the MAD method.

Clinical training in department of general dentistry at Tokyo Dental College Chiba Hospital.

A compulsory postgraduate clinical training program was established in April 2006 in Japan, and an applicants-only postgraduate training program 9 years ago at Tokyo Dental College. In addition, a training program was also established in the Department of General Dentistry at Tokyo Dental College Chiba Hospital in April 2002. The curriculum consists of training in the outpatient clinic and the following: 1) clinical training (preparation of written treatment plans, simulation practice, submission of evaluation sheets, and submission of training journals), 2) tutorials, and 3) case reports. In 1), trainees write treatment plans for new patients, discuss them with their instructor, perform simulation practice using dummies based on those discussions, submit evaluation sheets and training journals concerning treatment, and receive their instructor's assessment. In 2), trainees are divided into small groups, independently study themes they have chosen, and present the results. In 3), they orally report cases they have treated and receive evaluation by other trainees and instructors in general discussion meetings. In addition, a course was also established at the Department of General Dentistry, Tokyo Dental College Chiba Hospital in April 2002. We report the training curriculum of this course.