Liquid biopsy of wash samples obtained via endoscopic ultrasound-guided fine-needle biopsy: Comparison with liquid biopsy of plasma in pancreatic cancer.

OBJECTIVES: Pancreatic cancer (PC) has a poor prognosis and limited treatment options. Liquid biopsy, which analyzes circulating tumor DNA (ctDNA) in blood, holds promise for precision medicine; however, low ctDNA detection rates pose challenges. This study aimed to investigate the utility of wash samples obtained via endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) as a liquid biopsy for PC. METHODS: A total of 166 samples (42 formalin-fixed paraffin-embedded [FFPE] tissues, 80 wash samples, and 44 plasma samples) were collected from 48 patients with PC for genomic analysis. DNA was extracted and quantified, and 60 significantly mutated genes were sequenced. The genomic profiles of FFPE tissues, wash samples, and plasma samples were compared. Finally, the ability to detect druggable mutations in 80 wash samples and 44 plasma samples was investigated. RESULTS: The amount of DNA was significantly lower in plasma samples than in wash samples. Genomic analysis revealed a higher detection rate of oncogenic mutations in FFPE tissues (98%) and wash samples (96%) than in plasma samples (18%) and a comparable detection rate in FFPE tissues and wash samples. Tumor-derived oncogenic mutations were detected more frequently in wash samples than in plasma samples. Furthermore, the oncogenic mutations detection rate remained high in wash samples at all PC stages but low in plasma samples even at advanced PC stages. Using wash samples was more sensitive than plasma samples for identifying oncogenic and druggable mutations. CONCLUSIONS: The wash sample obtained via EUS-FNB is an ideal specimen for use as a liquid biopsy for PC.

A scoping review of seizure onset pattern in SEEG and a proposal for morphological classification.

BACKGROUND: Seizure onset pattern (SOP) represents an alteration of electroencephalography (EEG) morphology at the beginning of seizure activity in epilepsy. With stereotactic electroencephalography (SEEG), a method for intracranial EEG evaluation, many morphological SOP classifications have been reported without established consensus. These inconsistent classifications with ambiguous terminology present difficulties to communication among epileptologists. METHODS: We reviewed SOP in SEEG by searching the PubMed database. Reported morphological classifications and the ambiguous terminology used were collected. After thoroughly reviewing all reports, we reconsidered the definitions of these terms and explored a more consistent and simpler morphological SOP classification. RESULTS: Of the 536 studies initially found, 14 studies were finally included after screening and excluding irrelevant studies. We reconsidered the definitions of EEG onset, period for determining type of SOP, core electrode and other terms in SEEG. We proposed a more consistent and simpler morphological SOP classification comprising five major types with two special subtypes. CONCLUSIONS: A scoping review of SOP in SEEG was performed. Our classification may be suitable for describing SOP morphology.

Development of a molecular barcode detection system for pancreaticobiliary malignancies and comparison with next-generation sequencing.

BACKGROUND: Obtaining sufficient tumor tissue for genomic profiling is challenging in pancreaticobiliary cancer (PBCA). We determined the utility of molecular barcoding (MB) of liquid biopsies (bile, duodenal fluid, and plasma) for highly sensitive genomic diagnosis and detection of druggable mutations for PBCA. METHODS: Two in-house panels of 60 genes (non-MB panel) and 21 genes using MB (MB panel) were used for the genomic analysis of 112 DNA samples from 20 PBCA patients. We measured the yield of DNA and compared the genomic profiles of liquid samples obtained using the non-MB panel and the MB panel. The utility of the panels in detecting druggable mutations was investigated. RESULTS: A significantly greater amount of DNA was obtained from bile supernatants and precipitates compared to tumor samples (P < 0.001 and P = 0.001, respectively). The number of mutations per patient was significantly higher using the MB panel than using the non-MB panel (2.8 vs. 1.3, P = 0.002). Tumor-derived mutations were detected more frequently using the MB panel than the non-MB panel (P = 0.023). Five drug-matched mutations were detected in liquid samples. CONCLUSIONS: Liquid biopsy with MB may have utility in providing genomic information for the prognosis of patients with PBCA.

Use of an Endoscope Reduces the Size of Craniotomy Without Increasing Operative Time Compared With Conventional Microscopic Corpus Callosotomy.

BACKGROUND AND OBJECTIVES: Corpus callosotomy (CC) is an epilepsy surgery that disconnects the commissural fibers at the corpus callosum, a structure that often plays a key role in propagating seizure activity. CC is particularly beneficial in patients with drop attacks. Less invasive endoscopic surgeries have recently been introduced to some fields of neurosurgery but have not yet become common in epilepsy surgery. Endoscopic surgeries offer better visualization and require a smaller corridor than conventional microscopic surgeries. Here, we presented a case series comparing endoscopic CC with microscopic CC. METHODS: This 2-center retrospective study involved patients who underwent all types of CC (anterior, total, or posterior CC [pCC]) between January 2014 and May 2022. We excluded patients who underwent additional craniotomy for electrocorticography rather than CC, prior craniotomy, or CC without craniotomy. The primary outcomes were comparing size of craniotomy, operative time, and surgical complications between endoscopic CC and microscopic CC. RESULTS: We included 14 CCs in 11 patients in the endoscopic group and 58 CCs in 55 patients in the microscopic group. No significant difference in age was seen between groups. Craniotomies were significantly smaller in the endoscopic group for anterior (13.36 ± 1.31 cm 2 vs 27.55 ± 3.78 cm 2 ; P = .001), total (14.07 ± 2.54 cm 2 vs 26.63 ± 6.97 cm 2 ; P = .001), and pCC (9.44 ± 1.18 cm 2 vs 30.23 ± 10.76 cm 2 ; P = .002). Moreover, no significant differences in operative time (anterior CC [261 ± 53.11 min vs 298.73 ± 81.08 min, P = .226], total CC [339.5 ± 48.2 min vs 321.39 ± 65.98 min, P = .452], pCC [198 ± 24.73 min vs 242.5 ± 59.12 min, P = .240]), or complication rate were seen. CONCLUSION: Endoscopic CC is a promising technique requiring a smaller craniotomy than microscopic CC, without significantly increasing operative time or complication rate compared with microscopic CC.

Electrode Tip Shift During the Stereotactic Electroencephalography Evaluation Period with Boltless Suture Fixation.

BACKGROUND: Electrodes for stereotactic electroencephalography (SEEG) are typically fixed to the skull with anchor bolts. When anchor bolts are unavailable, electrodes have to be fixed using other methods, carrying the possibility of electrode shift. This study, therefore, evaluated the characteristics of electrode tip shift during SEEG monitoring in patients with electrodes fixed using the suture technique. METHODS: We retrospectively included patients who underwent SEEG implantation with suture fixation and evaluated the tip shift distance (TSD) of electrodes. Possible influences evaluated included: 1) implantation period, 2) lobe of entry, 3) unilateral or bilateral implantation, 4) electrode length, 5) skull thickness, and 6) scalp thickness difference. RESULTS: A total of 50 electrodes in 7 patients were evaluated. TSD was 1.4 ± 2.0 mm (mean ± standard deviation). Implantation period was 8.1 ± 2.2 days. Entry lobe was frontal for 28 electrodes and temporal for 22 electrodes. Implantation was bilateral for 25 electrodes and unilateral for 25 electrodes. Electrode length was 45.4 ± 14.3 mm. Skull thickness was 6.0 ± 3.7 mm. Scalp thickness difference was -1.5 ± 2.1 mm, which was found greater in temporal lobe entry compared with frontal lobe entry. According to univariate analyses, neither implantation period nor electrode length correlated with TSD. Multivariate regression analysis showed that only greater scalp thickness difference correlated significantly with greater TSD (P = 0.0018). CONCLUSIONS: Greater scalp thickness difference correlated with greater TSD. Surgeons need to consider the degree of scalp thickness difference and electrode shift when using suture fixation, especially with temporal lobe entry.

Comparison of genomic profiling of circulating tumor DNA in pancreaticobiliary malignancies in plasma and bile.

BACKGROUND: Obtaining sufficient pancreaticobiliary tumor tissue for genomic profiling has limitations. Liquid biopsies using plasma do not provide sufficient sensitivity. Thus, this study aimed to determine the effectiveness of liquid biopsy between bile and plasma for identifying oncogenic and drug-matched mutations. METHODS: This study created a panel of 60 significantly mutated genes specific to pancreaticobiliary cancer (PBCA) and used it for genomic analysis of 212 deoxyribonucleic acid (DNA) samples (87 bile supernatant, 87 bile precipitate, and 38 plasma) from 87 patients with PBCA. The quantity of extracted DNA from bile and plasma was compared, as were genomic profiles of 38 pairs of bile and plasma from 38 patients with PBCA. Finally, we investigated 87 bile and 38 plasma for the ability to detect druggable mutations. RESULTS: The amount of DNA was significantly lower in plasma than in bile (p < .001). Oncogenic mutations were identified in 21 of 38 (55%) patients in bile and nine (24%) in plasma samples (p = .005). Bile was significantly more sensitive than plasma in identifying druggable mutations (p = .032). The authors detected 23 drug-matched mutations in combined bile and plasma, including five ERBB2, four ATM, three BRAF, three BRCA2, three NF1, two PIK3CA, one BRCA1, one IDH1, and one PALB2. CONCLUSIONS: Liquid biopsy using bile may be useful in searching for therapeutic agents, and using the obtained genomic information may improve the prognoses of patients with PBCA. PLAIN LANGUAGE SUMMARY: Genomic profiling of formalin-fixed paraffin-embedded tissues may provide actionable targets for molecular and immuno-oncological treatment. However, most pancreaticobiliary malignancies are unresectable and formalin-fixed paraffin-embedded tissues cannot be obtained. Although comprehensive genomic profiling tests using plasma have been used in recent years, the utility of those using bile is not clear. Our study revealed that bile identified more drug-matched mutations than plasma in advanced pancreaticobiliary cancer patients. Bile may help widen the patient population benefiting from targeted drugs.

[Surgical Treatment of Mesial Temporal Lobe Epilepsy Focusing on Anatomical Understanding].

Surgical treatment is an effective option for medically intractable epilepsy. Amygdalohippocampectomy for mesial temporal lobe epilepsy is a surgically remediable epileptic syndrome. It is a well-established surgery and various approaches to the mesial temporal lobe have been reported. To reduce the complication rate, surgeons should have sufficient knowledge of anatomy in the mesial temporal region. Here, we summarize the surgical treatments for mesial temporal lobe epilepsy, focusing on anatomical understanding. We described in detail the surgical anatomy of amygdalohippocampectomy and various approaches to the mesial temporal region. In addition, we describe hippocampal transection aimed at preserving memory function, which is an alternative surgery in patients without hippocampal sclerosis. An anatomical understanding of the mesial temporal region helps surgeons not only in the field of epilepsy surgery, but also in other fields of neurosurgery, such as brain tumor and vascular surgery.

Case report and review of the literature of primary central nervous system lymphoma of the fourth ventricle.

Background: Primary central nervous system lymphoma of the fourth ventricle is very rare. We present a case of primary central nervous system lymphoma originating from the fourth ventricle and review cases reported in the literature. Case Description: A 54-year-old man with no previous medical history presented with headache and nausea. Magnetic resonance imaging showed a homogeneously enhancing tumor in the fourth ventricle and obstructive hydrocephalus. We performed biopsy of the tumor, which was diagnosed pathologically as diffuse large B-cell lymphoma. Although the tumor disappeared after 5 cycles of R-MPV regimen, the patient required repeated ventricular drainage and finally received a ventriculoperitoneal shunt. Complete response was achieved after 2 cycles of high-dose cytarabine chemotherapy with an autologous peripheral blood stem cell transplant. There was no sign of recurrence at 20 months after biopsy. Conclusion: Morbidity arising due to radical resection/radiotherapy of resistant primary central nervous system lymphoma originating from the fourth ventricle could be prevented by ventriculoperitoneal shunting with chemotherapy and autologous blood stem cell transplantation.

Genomic profiling amplifies the utility of endoscopic ultrasound-guided fine needle biopsy by identifying clinically applicable druggable mutations in pancreatic cancer.

BACKGROUND: Genomic profiling of tumors is available, but whether the small fragment obtained via endoscopic ultrasound-guided fine needle biopsy (EUS-FNB) is sufficient for these examinations is unknown. Here we investigated whether EUS-FNB specimens are suitable for genomic profiling to identify oncogenic and drug-matched mutations. METHODS: We constructed a pancreatobiliary cancer panel for targeted panel sequencing that covered 60 significantly mutated genes and compared the results with those of whole-exome sequencing (WES). In total, 20 and 53 formalin-fixed paraffin-embedded tissues obtained via surgery and EUS-FNB were analyzed, respectively. First, we examined the DNA quality and genomic profiles of 20 paired samples from 20 malignant lesions obtained via surgery and EUS-FNB. We then tested 33 samples obtained via EUS-FNB from 24 malignant and 9 benign lesions for the discrimination of malignancy. Finally, we explored drug-matched mutations from EUS-FNB specimens. RESULTS: Although the DNA quantity obtained via surgery was higher than that obtained via EUS-FNB (P = 0.017), the DNA quality and mean depth were equivalent (P = 0.441 and P = 0.251). Panel sequencing of EUS-FNB specimens identified more oncogenic mutations than WES (90 % vs. 50 %). Furthermore, the number of oncogenic mutations did not differ between EUS-FNB and surgically resected specimens. Genomic profiling of EUS-FNB specimens enabled the discrimination of malignancy with 98 % accuracy. Of 44 malignant lesions, drug-matched alterations were identified in 14 % (6/44) of malignant lesions. CONCLUSION: EUS-FNB specimens can be widely utilized for diagnostic purposes, discrimination of malignancy, and detection of drug-matched mutations for the treatment of pancreatic cancer.

Detection of actionable mutations in cytological specimens obtained by endoscopic ultrasound-guided fine needle aspiration with rapid onsite evaluation in pancreatic cancer.

BACKGROUND: It is not clear whether archived cytological specimens (ACSs) obtained with endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) with rapid onsite evaluation (ROSE) can be used for genomic profiling of tumors. We used ACSs to perform genomic analysis of specimens to identify oncogenic and druggable mutations. METHODS: A panel of 60 significantly mutated genes specific to pancreatobiliary cancer was created and used for genomic analysis of 113 specimens of 44 formalin-fixed paraffin-embedded (FFPE) tissues and 69 ACSs obtained by EUS-FNA with ROSE were included. The quantity and quality of DNA extracted from FFPE tissues and ACSs were compared. We also compared DNA from spray and touch ACSs. Next, genomic profiles were compared. We also evaluated detection of target gene mutations in each specimen. RESULTS: The amount of DNA in FFPE tissues was greater than in ACSs (P = 0.014), but the quality of DNA was comparable (P = 0.378). There was no quantitative or qualitative difference between spray and touch ACSs (P = 0.154 and P = 0.734, respectively). Oncogenic mutations were shared at 82 % in FFPE tissues and ACSs and 82 % in spray and touch ACSs. The sensitivity of genomic analysis in ACSs was 97 % (67 of 69), which was comparable to that of cytology (62 of 69, 90 %; P = 0.165), and was significantly higher than that of histology (32/44, 73 %; P < 0.001). Drug-matched mutations were identified in five of the 44 lesions (11 %). CONCLUSION: Genomic analysis of ACSs is useful in the prognosis of pancreatic cancer because detection of driver mutations is similar to detection in FFPE tissues.

Primary Experiences with Robot-assisted Navigation-based Frameless Stereo-electroencephalography: Higher Accuracy than Neuronavigation-guided Manual Adjustment.

The use of robot-assisted frameless stereotactic electroencephalography (SEEG) is becoming more common. Among available robotic arms, Stealth Autoguide (SA) (Medtronic, Minneapolis, MN, USA) functions as an optional instrument of the neuronavigation system. The aims of this study were to present our primary experiences with SEEG using SA and to compare the accuracy of implantation between SA and navigation-guided manual adjustment (MA). Seventeen electrodes from two patients who underwent SEEG with SA and 18 electrodes from four patients with MA were retrospectively reviewed. We measured the distance between the planned location and the actual location at entry (De) and the target (Dt) in each electrode. The length of the trajectory did not show a strong correlation with Dt in SA (Pearson's correlation coefficient [r] = 0.099, p = 0.706) or MA (r = 0.233, p = 0.351). De and Dt in SA were shorter than those in MA (1.99 ± 0.90 vs 4.29 ± 1.92 mm, p = 0.0002; 3.59 ± 2.22 vs 5.12 ± 1.40 mm, p = 0.0065, respectively). SA offered higher accuracy than MA both at entry and target. Surgical times per electrode were 38.9 and 32 min in the two patients with SA and ranged from 51.6 to 88.5 min in the four patients with MA. During the implantation period of 10.3 ± 3.6 days, no patients experienced any complications.

The Use of Electronic Medical Records-Based Big-Data Informatics to Describe ALT Elevations Higher than 1000 IU/L in Patients with or without Hepatitis B Virus Infection.

Hepatitis B virus (HBV) infection is one of the serious health problems in the world as HBV causes severe liver diseases. Moreover, HBV reactivation has occasionally been observed in patients with resolved HBV infection and patients using immunosuppression and anticancer drugs. Large-scale hospital data focused on HBV infection and severe liver function were analyzed at our hospital, located in an urban area adjacent to Tokyo, the capital city of Japan. A total of 99,932 individuals whose blood samples were taken at 7,170,240 opportunities were analyzed. The HBV surface antigen (HBsAg)-positive group had a more frequent prevalence of patients with higher transaminase elevations than the HBsAg-negative group. However, among the HBsAg-negative group, patients who were positive for anti-HBV surface antibody and/or anti-HBV core antibody, had more severe liver conditions and fatal outcomes. More careful attention should be paid to alanine transaminase (ALT) elevations higher than 1000 IU/L in patients who had current and previous HBV infection.

Endoscopic Transcortical Selective Amygdalohippocampectomy for Mesial Temporal Lobe Epilepsy: 2-Dimensional Operative Video.

This surgical video shows a 19-yr-old woman with focal impaired awareness seizures. Seizure semiology showed no lateralizing signs. Ictal electroencephalography (EEG) failed to determine the seizure origin. Interictal EEG showed bilateral spike-and-waves at the temporal electrodes. Magnetic resonance imaging (MRI) showed suspected hippocampal sclerosis on the right side. To determine the side of the focus, depth electrodes were implanted in both hippocampi. Invasive video EEG identified the seizure origin on the right. The decision was made to perform selective amygdalohippocampectomy (SelAH) via the middle temporal gyrus (MTG). An endoscope was used to minimize the craniotomy and shorten the skin incision. A 5-cm linear skin incision and 2.5-cm craniotomy were made. A thin tube was inserted to the inferior horn of the lateral ventricle (Inf-H) under neuronavigation to guide the route to the Inf-H. The endoscope was introduced. A 1.5-cm corticotomy was made at the MTG, and white matter was aspirated until opening the Inf-H. The hippocampus and parahippocampal gyrus were removed with the usual steps in microsurgical SelAH. The surgical time was 4 h 20 min. The patient was discharged without complications and has remained seizure free. In addition to the preoperative objectives, using an endoscope widens the surgical view in the Inf-H compared with microsurgical procedures. Although seizure and cognitive outcomes are expected to be comparable to those from other methods of SelAH, invasiveness might be reduced. This appears to represent the first video report of endoscopic SelAH. The patient consented to the procedure and publication of her images and surgical video.

Detection of actionable mutations in archived cytological bile specimens.

BACKGROUND/PURPOSE: There are limitations in obtaining sufficient pancreaticobiliary tumor tissue for genomic profiling of tumors. Herein, we investigated whether archived cytological specimen (ACS) is suitable for genomic profiling to identify oncogenic and drug-matched mutations. METHODS: We constructed a pancreaticobiliary cancer panel for targeted sequencing covering 60 significantly mutated genes (280 220 bp). Eighty DNA samples (19 formalin-fixed paraffin-embedded [FFPE] tissues and 61 ACS) from 44 patients with pancreaticobiliary disease were analyzed. We compared genomic profiles of 19 FFPE and 29 ACS from 19 patients with malignancies (Validation Cohort). We tested 32 ACS from 25 patients (15 malignant and 10 benign) for the ability to discriminate between malignant and benign disorders (Testing Cohort). We explored whether actionable and drug-matched mutations (Validation and Testing Cohorts) could be identified from ACS. RESULTS: Oncogenic mutations observed in ACS were identical to those identified in FFPE specimens (76% consistency). Genomic profiling using only ACS discriminated between malignant and benign disorders with 93% accuracy, 91% sensitivity, and 100% specificity. Actionable and drug-matched mutations were identified in 74% and 32% of ACS, respectively, and in 79% and 21% in FFPE samples, respectively. CONCLUSION: Archived cytological specimen may be used to discriminate malignancy and to detect drug-matched mutations in patients with advanced pancreaticobiliary cancer.

Rapidly declining trend of signet ring cell cancer of the stomach may parallel the infection rate of Helicobacter pylori.

BACKGROUND: Studies indicate that gastric cancer (GC) incidence has decreased, whereas signet ring cell carcinoma (SRC) incidence has increased. However, recent trends in GC incidence are unclear. We used our hospital cancer registry to evaluate the changes in the incidence of GC, SRC, and non-SRC (NSRC) over time in comparison to changes in the H. pylori infection rates over time. METHODS: We identified 2532 patients with GC enrolled in our registry between January 2007 and December 2018 and statistically analyzed SRC and NSRC incidence. The H. pylori infection rate in patients with SRC was determined by serum anti-H. pylori antibody testing, urea breath test, biopsy specimen culture, and immunohistochemical analysis (IHC) of gastric tissue. Additionally, genomic detection of H. pylori was performed in SRCs by extracting DNA from formalin-fixed paraffin-embedded gastric tissue and targeting 16S ribosomal RNA of H. pylori. RESULTS: Overall, 211 patients had SRC (8.3%). Compared with patients with NSRC, those with SRC were younger (P <  0.001) and more likely to be female (P <  0.001). Time series analysis using an autoregressive integrated moving average model revealed a significant decrease in SRC (P <  0.001) incidence; NSRC incidence showed no decline. There was no difference in H. pylori infection prevalence between the SRC and NSRC groups. IHC and genomic methods detected H. pylori in 30 of 37 (81.1%) SRCs. CONCLUSIONS: Reduction in H. pylori infection prevalence may be associated with the decrease in the incidence of SRC, which was higher than that of NSRC.

Validation of Tokyo Guideline 2013 as Treatment of Acute Cholecystitis by Real World Data.

BACKGROUND: The Tokyo Guidelines (TG; 2013) indicated that emergency cholecystectomy is an important early treatment option for acute cholecystitis; however, surgical intervention is not necessarily indicated in patients with advanced age. We evaluated percutaneous transhepatic gallbladder aspiration (PTGBA), percutaneous transhepatic gallbladder drainage (PTGBD), and the administration of antibiotics alone as treatment options for acute -cholecystitis. METHODS: From January 2010 to December 2017, 159 patients with acute cholecystitis were treated at our institution. The data from these patients were retrospectively analyzed. RESULTS: Of these 159 cases, 109 underwent PTGBA, 28 underwent PTGBD, and 22 were administered antibiotics alone. None of the 159 patients needed urgent (early) cholecystectomy, and all patients were discharged without mortality. PTGBA was unsuccessful in only 6 of 109 patients; PTGBD was performed in these 6 cases. Long-term follow-up was conducted in all cases. Of the 159 patients, 146 had gallbladder stones initially, while 13 had none at the time of presentation. Of these 146 patients with gallbladder stones, 84 underwent elective cholecystectomy, while 62 did not. Of the 84 patients who underwent elective cholecystectomy, 2 developed choledocholithiasis; of the 62 patients who did not undergo elective cholecystectomy, 5 developed choledocholithiasis and 2 developed acute cholecystitis. The incidences of choledocholithiasis and acute cholecystitis did not significantly differ between the 2 groups (p = 0.06). CONCLUSIONS: Despite the recommendations in the TG (2013), emergency cholecystectomy was not needed in any of the present patients with acute cholecystitis. Acute cholecystitis can be successfully treated with -PTGBA or PTGBD, which are simple procedures with good short- and long-term safety. These procedures are highly recommended for patients with acute cholecystitis, especially in the elderly population.

Deficiency of mismatch repair genes is less frequently observed in signet ring cell compared with non-signet ring cell gastric cancer.

Signet ring cell (SRC) gastric cancer at advanced stage has poor prognosis. While a recent study reported nearly one-third of SRC cases contain tumors with deficient mismatch repair (MMR) genes, other studies in SRC have been inconclusive. To re-analyze the results, we performed immunohistochemical staining of MLH1, MSH2, MSH6 and PMS2 proteins in 38 SRC gastric tumors compared with 109 non-SRC (NSRC) tumors from 94 patients. In contrast to the previous study, all SRC gastric tumors normally expressed MMR proteins, whereas 22 of 109 of NSRC (20%) showed deficient MMR proteins. To reinforce our results, we referred to the Cancer Genome Atlas (TCGA) genomic database and found that only 6 (6%) of 99 samples with diffuse gastric tumors showed deficient MMR, whereas 64 (21%) of 304 in intestinal gastric tumors showed deficient MMR. Our results as well as the TCGA database indicated that MMR genes are infrequently inactivated in SRC gastric cancer. These findings indicate that SRC patients may not be the best candidates for immuno-oncology therapy.

Molecular subtype switching in early-stage gastric cancers with multiple occurrences.

BACKGROUND: Multiple gastric cancers at the same time (synchronous) or recurrence after 1 year (metachronous) are frequently encountered. Since their genetic profiles were not well elucidated, we molecularly subtyped the genetic events of synchronous and metachronous early-stage gastric cancers. METHODS: We studied mismatch repair (MMR) genes in 84 tumors from 31 patients (15 synchronous and 16 metachronous) by immunohistochemistry. We performed microsatellite instability analysis and targeted sequencing of 58 significantly mutated genes (SMGs) in 35 tumors from thirteen patients. Genomic data from TCGA were used for comparisons with advanced-stage cancers. RESULTS: Among the 31 patients, at least one deficient-MMR (dMMR) tumor was observed in eight (26%). Of eight patients, seven showed a mixture of proficient-MMR (pMMR) and dMMR tumors. The one case with only dMMR had six recurrent tumors within 2 years. To further subtype, we sequenced 58 SMGs in 35 samples (25 pMMR and 10 dMMR) from thirteen patients. In 35 samples, 163 mutations were identified, but none matched in almost cases, strongly indicating different clonal origins, whether synchronous or metachronous occurrences. Of the 25 pMMR cases, 1 belonged to Epstein-Barr virus (EBV), 24 belonged to chromosomal instability (CIN) subtypes. Of the thirteen cases, repetitive CIN, a mixture of CIN and MSI, a mixture of CIN and EBV, and repetitive MSI were observed in nine (70%), two (15%), one (8%) and one (8%), respectively. CONCLUSIONS: Despite multiple tumors occurring in the same patient simultaneously or several years apart, clonal origin was totally different. 'Switching' or 'mixing' of dMMR and pMMR, EBV or CIN occurred, which had clinical relevance with regard to immunotherapy.

The efficacy and safety of lenvatinib for advanced hepatocellular carcinoma in a real-world setting.

BACKGROUND/PURPOSE: Lenvatinib (an inhibitor of vascular endothelial growth factor (GF) receptors 1-3, fibroblast GF receptors 1-4, platelet-derived GF receptor α, rearranged during transfection, and stem cell factor receptor) was non-inferior to sorafenib in a phase 3 (REFLECT) trial of advanced hepatocellular carcinoma. This study examined the efficacy and safety of lenvatinib in a real-world setting. METHODS: This was a retrospective, multicenter, observational study. Inclusion and exclusion criteria were based on the phase 3 trial, and participants were observed for at least 12 weeks. Therapeutic effect was determined using the modified Response Evaluation Criteria In Solid Tumors (m-RECIST) at the 8th week. Patients received oral lenvatinib 12 mg/day (body weight > 60 kg) or 8 mg/day (body weight < 60 kg). Dose interruptions followed by reductions for lenvatinib-related toxicities were permitted. Grades of adverse events (AEs) complied with the Common Terminology Criteria for Adverse Events version 4.0. RESULTS: All 16 patients included in this study had prior treatment history, and a median 3.9 years had passed since the first treatment. Fatigue, hypertension, and proteinuria were the most frequent AEs, and were higher than Grade 2. AEs could be controlled by appropriate dose reduction, interruption, and symptomatic treatment according to the protocol. In the m-RECIST evaluation at the 8th week, 0, 6, 8, and 1 patients had achieved complete response, partial response, stable disease, and progressive disease, respectively. The objective response rate was 40%. CONCLUSION: Lenvatinib treatment could be accomplished with safety and good response in a real-world setting.

Influence of NUDT15 variants on hematological pictures of patients with inflammatory bowel disease treated with thiopurines.

AIM: The single nucleotide polymorphism (SNP) c.415C>T in exon 3 of NUDT15 affects thiopurine-induced leukopenia in Asian patients with Crohn's disease. Meanwhile, three additional genetic variants of NUDT15 were reported in patients with acute lymphoblastic leukemia. We evaluated the effects of these additional genetic variants of NUDT15 in patients with inflammatory bowel disease (IBD) treated with thiopurines. METHODS: Ninety-six Japanese patients with IBD were enrolled. Genotyping for the NUDT15 and TPMT genes was performed using Custom TaqMan SNP genotyping assays or Sanger sequencing. The changes in white blood cell (WBC) count, mean corpuscular volume (MCV), platelet count, hemoglobin, CRP, amylase, albumin, AST, ALT, and ESR were evaluated. RESULTS: Genetic variants of exon 1 and exon 3 of NUDT15 were identified in 24 of 96 patients (25.0%). C.52G > A and c.36_37insGGAGTC in exon 1 were found in three patients each. All three patients with c.36_37insGGAGTC in exon 1 were heterozygotes of p.Arg139Cys in exon 3. Eighteen patients had p.Arg139Cys in exon 3 alone. The WBC count gradually decreased after initiation of thiopurine treatment in the mutated cases (n = 24), and was significantly lower at 6, 8, 10, and 16 wk (P = 0.0271, 0.0037, 0.0051, and 0.0185, respectively). The WBC counts were also evaluated in patients with and without prednisolone treatment. In the patients with prednisolone treatment, the WBC count tended to show a greater decrease in the mutated cases, with significant differences at 8 and 10 wk (P = 0.012 and 0.029, respectively). In the patients without prednisolone treatment, the WBC count was significantly lower at 2, 4, 8, and 14 wk in mutated cases (P = 0.0196, 0.0182, 0.0237 and 0.0241, respectively). MCV increased after starting thiopurine treatment in the mutated cases, and was significantly higher at 10 wk (P = 0.0085). Platelet count, hemoglobin, CRP, amylase, albumin, AST, ALT and ESR did not differ significantly between the wild-type and mutated cases. TPMT mutations were not found in any of the patients. CONCLUSION: Mutations in exon 1 of NUDT15 also affect thiopurine-induced leukopenia in patients with IBD. To discuss thiopurine-induced leukopenia in more detail, investigation of SNPs in both exon 1 and exon 3 of NUDT15 is needed.