Gastrointestinal stromal tumors (GISTs) are the most frequent malignant mesenchymal tumors in the gastrointestinal tract. The clinical incidence of GISTs is estimated 10/million/year; however, the ...true incidence is complicated by frequent findings of tiny GISTs, of which the natural history is unknown. The initial work-up with endoscopy and endoscopic ultrasonography plays important roles in the differential diagnosis of GISTs. Surgery is the only modality for the permanent cure of localized GISTs. In terms of safety and prognostic outcomes, laparoscopy is similar to laparotomy for GIST treatment, including tumors larger than 5 cm. GIST progression is driven by mutations in KIT or PDGFRA or by other rare gene alterations, all of which are mutually exclusive. Tyrosine kinase inhibitors (TKIs) are the standard therapy for metastatic/recurrent GISTs. Molecular alterations are the most reliable biomarkers for TKIs and for other drugs, such as NTRK inhibitors. The pathological and genetic diagnosis prior to treatment has been challenging; however, a newly developed endoscopic device may be useful for diagnosis. In the era of precision medicine, cancer genome profiling by targeted gene panel analysis may enable potential targeted therapy even for GISTs without KIT or PDGFRA mutations.
The association between the tumor microenvironment (TME) and treatment response or survival has been a recent focus in several types of cancer. However, most study materials are resected specimens ...that were completely modified by prior chemotherapy; therefore, the unmodified host immune condition has not yet been clarified. The aim of the present study was to evaluate the relationship between TME assessed in pre–therapeutic biopsy samples and chemoresistance in esophageal cancer (EC). A total of 86 endoscopic biopsy samples from EC patients who received neoadjuvant chemotherapy (NAC) prior to surgery were evaluated for the number of intratumoral CD4+ lymphocytes (with/without Foxp3 expression), CD8+ lymphocytes (with/without PD‐1 expression), monocytes (CD14+) and macrophages (CD86+, CD163+ and CD206+) by multiplex immunohistochemistry (IHC). The number of tumor‐infiltrating CD206+ macrophages I significantly correlated with cT, cM, cStage and neutrophil/lymphocyte ratio (NLR), whereas the number of lymphocytes (including expression of Foxp3 and PD‐1) was not associated with clinico‐pathological features. The high infiltration of CD163+ or CD206+ macrophages was significantly associated with poor pathological response to NAC (P = 0.0057 and 0.0196, respectively). Expression of arginase‐1 in CD163+ macrophages tended to be higher in non–responders (29.4% vs 18.2%, P = 0.17). In addition, patients with high infiltration of M2 macrophages exhibited unfavorable overall survival compared to those without high infiltration of M2 macrophages (5‐year overall survival 57.2% vs 71.0%, P = 0.0498). Thus, a comprehensive analysis of TME using multiplex IHC revealed that M2 macrophage infiltration would be useful in predicting the response to NAC and long‐term survival in EC patients.
The present study confirmed that pre–therapeutic M2 macrophage infiltration would be a useful biomarker in predicting the response to NAC and unfavorable survival among a variety of immune cells in EC patients. Our results support the possibility of using immunotherapy, targeting M2 macrophages, alongside conventional neoadjuvant chemotherapy.
A high maximum frequency of oscillation (f max ) of 910 GHz was achieved at InAlAs/InGaAs highelectron mobility transistors (HEMTs) with a relatively long gate length (L G ) of 75 nm by adopting an ...asymmetric gate recess and a double-side-doped structure. The f max improved significantly by extending the drain-side gate recess length (L RD ) to 250 nm; meanwhile, the source-side gate-recess length (L RS ) was kept to 70 nm. The improvement in fmax was due to a decrease in the drain output conductance (g d ) and drain-to-gate capacitance (CGD) after the extension of L RD . gd was further suppressedby applying a double-side-doped structure to the InP-based HEMTs. A reduction in g d resulted in a drastic improvement in f max even though L G was a longer value.
The mechanism of liquefaction and the factors that cause liquefaction behavior have previously been examined and evaluated, both analytically and experimentally; construction including liquefaction ...countermeasures is being implemented, based on these findings. This study presents a theoretical visualization of the mechanism of liquefaction generation and evaluates the behavior of particles in the ground. Specifically, an MPSM-DEM coupled CAE system (CAES) is employed to view the events beneath the ground, modeled three-dimensionally when an external acceleration is applied to simulate seismic waves and reveals the behavior below the surface. The numerical simulation of the liquefaction phenomenon, as represented by an MPSM-DEM coupled CAES system, clearly showed the mechanism of liquefaction generation and contributed to the design and accountability of more economical and sustainable liquefaction countermeasures, regardless of the field of specialization.
Background
Microsatellite instability (MSI) and programmed death-ligand 1 (PD-L1) are candidate predictors for the response to immune checkpoint inhibitors, and may predict chemotherapy sensitivity. ...We investigated the simultaneous expression of mutL homolog 1 (MLH1), a mismatch repair gene, and PD-L1 in gastric cancers.
Methods
We examined MLH1 and PD-L1 expression in surgical specimens from 285 gastric cancer patients treated with or without preoperative chemotherapy, and assessed the relation between expression results and both histological response and recurrence-free survival (RFS).
Results
Of 285 patients, 28 (9.8%) and 70 (24.6%) exhibited negative MLH1 and high PD-L1 expression, respectively. Most MLH1-negative tumors (85.7%) showed high MSI, and these tumors exhibited high PD-L1 expression more frequently than MLH1-positive tumors (57.1% vs. 21.0%,
P
< 0.001). MLH1-negative patients were significantly less likely to respond to preoperative chemotherapy than MLH1-positive patients (16.7% vs. 61.2%,
P
= 0.005), whereas there was no significant difference between high- and low-PD-L1 expression patients (55.9% vs. 56.6%,
P
= 0.95). RFS in patients without preoperative chemotherapy was significantly longer in the MLH1-negative group than in the MLH1-positive group (HR 0.30; 95% CI 0.09–0.95;
P
= 0.030), whereas in patients with preoperative chemotherapy there was no significant difference in RFS between the two groups (HR 0.70; 95% CI 0.30–1.63;
P
= 0.41). PD-L1 expression was not associated with RFS in patients with or without chemotherapy.
Conclusions
Loss of MLH1 was associated with chemoresistance and did not prolong survival following neoadjuvant chemotherapy. The strong association between MLH1 and MSI status suggests that immune checkpoint inhibitors may be preferable to conventional chemotherapy for MLH1-negative gastric cancer.
To evaluate pathological response to NAC in metastatic LNs, and assess its clinical prognostic significance in patients with EC.
The pathological response to preoperative treatment is commonly ...evaluated in the PT. However, LN metastases strongly correlate with systemic micro-metastases. Thus, pathological evaluation of LN response could more accurately predict prognosis in EC patients undergoing NAC before surgery.
We enrolled 371 consecutive patients who underwent triplet NAC followed by surgery for EC between January 2010 and December 2016. Pathological LN regression grade was defined by the proportion of viable tumor area within the whole tumor bed area for all metastatic LNs: grade I, >50%; II, 10%-50%; III, <10%; and IV, 0%. We analyzed the correlation of grade with clinico-pathological parameters.
Among 319 patients with clinically positive LNs, pathological LN regression grades were I/II/III/IV in 115/51/58/95 patients, and 191 patients (59.9%) showed discordance between the PT and LN pathological regression grades. LN regression grade significantly correlated with cN positive number, ypTNM, lymphovascular invasion, and clinical/pathological PT response. Multivariate analysis for recurrence-free survival revealed that LN regression grade hazard ratio (HR) = 2.25, P < 0.001, ypT (HR = 1.65, P = 0.005), and ypT (HR = 1.62, P = 0.004) were independent prognostic factors, but not pathological PT regression grade (P = 0.67).
Compared to PT response, pathological LN response better predicted long-term survival in EC patients who received NAC plus curative surgery.
To investigate the residual pattern of esophageal cancer in the esophageal wall after neoadjuvant chemotherapy (NAC) and its clinical significance.
NAC is a standard treatment for locally advanced ...esophageal cancer; however, residual tumor patterns in resected specimens after NAC and their clinico-pathological characteristics remain unknown.
One hundred twenty consecutive patients with cT3 or deeper esophageal cancer underwent curative esophagectomy after NAC and achieved grade 2 histological responses between 2000 and 2016. Hematoxylin-eosin staining of residual tumor sections revealed 4 remnant categories: Type 1: shallow, Type 2: central, Type 3: deep, and Type 4: diffuse. We examined associations between these Types and clinico-pathological factors, including prognosis.
Forty-five (38%) specimens had no residual tumor cells in the mucosal layer. The adventitia layer displayed the lowest residual tumor cell frequency (18%) among all layers. Types 1, 2, 3, and 4 residual tumor patterns were found in 49 (41%), 33 (28%), 9 (8%), and 29 (24%) patients, respectively. Type 4 showed the maximum standard uptake value after NAC; Types 3 and 4 had higher ratios of venous invasion than Type 1 or 2. Patients with Type 3 or 4 more frequently developed pleural dissemination or distant metastasis than patients with Type 1 or 2. Survival was similar among the 4 Types.
After NAC for locally advanced esophageal cancer, the shallow residual tumor pattern was most common, but approximately 40% of specimens showed no tumor cells in the mucosal layer. Deep and diffuse remnant patterns were associated with high risks of pleural dissemination and distant metastasis.
Predictive factors of nivolumab treatment response in patients with gastric cancer (GC) remain unclear.
In this retrospective cohort study, tissue specimens of patients with unresectable or recurrent ...GC and prior or scheduled treatment with nivolumab as third-line or higher therapy between September 2017 and February 2019 were collected from 23 institutions. The tumour-positive score (TPS) and combined positive score (CPS) of PD-L1 expression and mismatch repair (MMR) were analysed by immunohistochemistry. Associations between clinicopathological factors and tumour-response rate, hyperprogressive disease (HPD) rate and survival were assessed.
Of 200 eligible patients, 143 had measurable lesions. The response and HPD rates were 17.5% and 22.1%, respectively. The response rate was significantly higher in patients with performance status (PS) 0-1 (P = 0.026), non-peritoneal metastasis (P = 0.021), PD-L1 TPS ≥ 1 (P = 0.012), CPS ≥ 5 (P = 0.007) or ≥ 10 (P < 0.001) or MMR deficiency (P < 0.001). The HPD rate was significantly higher in patients with PS 2-3 (P = 0.026), liver metastasis (P < 0.001) and CPS < 10 (P = 0.048). Multivariate analysis revealed that CPS (P = 0.001) and MMR (P = 0.002) were independent prognostic factors of progression-free survival, as well as liver metastasis (P < 0.001), peritoneal metastasis (P = 0.004) and CRP (P < 0.001).
PD-L1 CPS and MMR could be useful biomarkers for nivolumab treatment efficacy in GC.
UMIN000032164.
Rituximab is a highly effective agent that is used in the treatment of B-cell lymphoma. Rituximab-induced acute thrombocytopenia is a rare side effect that has previously been reported in a small ...number of patients with malignant lymphoma; its mechanism is still unknown. We herein report the case of a 74-year old man who was diagnosed with follicular lymphoma and who developed severe acute thrombocytopenia the day after the administration of rituximab. Coagulation abnormality, which mimicked disseminated intravascular coagulation, also appeared. When physicians use rituximab to treat high-risk patients, the platelet count should be closely monitored to avoid possible adverse events.
Background
Body weight loss (BWL) after gastrectomy is associated with not only a deteriorated quality of life but also a poor prognosis. Oral nutritional supplements (ONS) may be used to minimize ...BWL, which is observed in the first 3 months after gastrectomy and becomes stable thereafter, although the results of several randomized trials remain controversial.
Methods
We performed a multicenter, open-label randomized controlled trial including 1003 gastric cancer patients undergoing curative gastrectomy. Patients were assigned to the ONS group or the control group. In the former, 400 ml (400 kcal) per day for 12 weeks as enteral nutrition was planned, and the actual intake amount was recorded daily by patients themselves. The primary endpoint was BWL 1 year after gastrectomy.
Results
BWL data were available in 880 patients (ONS 437, control 443). BWL at 3 months was significantly lower in the ONS group than in the control group (7.1 ± 5.6% and 8.5 ± 5.8%,
p
= 0.0011). However, the difference gradually declined after 6 months and was not significant 1 year after surgery (9.3 ± 8.2% and 9.8 ± 8.7%,
p
= 0.37). In the ONS group, 50.4% of patients took more than 200 ml/day of ONS (average 301 ml) and showed significantly less BWL (8.2 ± 7.2%) at 1 year than the control (
p
= 0.0204).
Conclusion
The administration of ONS for 12 weeks after gastrectomy did not improve BWL at 1 year. However, the improvement in BWL remained until 1 year after surgery in patients who took more than 200 kcal/day of ONS.
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