Gastric cancer is the world's third leading cause of cancer mortality. In spite of significant therapeutic improvements, the clinical outcome for patients with advanced gastric cancer is poor; thus, the identification and validation of novel targets is extremely important from a clinical point of view. We generated a wide, multilevel platform of gastric cancer models, comprising 100 patient-derived xenografts (PDX), primary cell lines, and organoids. Samples were classified according to their histology, microsatellite stability, Epstein-Barr virus status, and molecular profile. This PDX platform is the widest in an academic institution, and it includes all the gastric cancer histologic and molecular types identified by The Cancer Genome Atlas. PDX histopathologic features were consistent with those of patients' primary tumors and were maintained throughout passages in mice. Factors modulating grafting rate were histology, TNM stage, copy number gain of tyrosine kinases/KRAS genes, and microsatellite stability status. PDX and PDX-derived cells/organoids demonstrated potential use-fulness to study targeted therapy response. Finally, PDX transcriptomic analysis identified a cancer cell-intrinsic microsatellite instability (MSI) signature, which was efficiently exported to gastric cancer, allowing the identification, among microsatellite stable (MSS) patients, of a subset of MSI-like tumors with common molecular aspects and significant better prognosis. In conclusion, we generated a wide gastric cancer PDX platform, whose exploitation will help identify and validate novel "druggable" targets and optimize therapeutic strategies. Moreover, transcriptomic analysis of gastric cancer PDXs allowed the identification of a cancer cell-intrinsic MSI signature, recognizing a subset of MSS patients with MSI transcriptional traits, endowed with better prognosis.Significance: This study reports a multilevel platform of gastric cancer PDXs and identifies a MSI gastric signature that could contribute to the advancement of precision medicine in gastric cancer.

Background The association between compliance to an enhanced recovery protocol (ERAS) and outcome after surgery for gastric cancer has been poorly investigated, particularly in Western patients. The aim of the study was to evaluate whether the rate of adherence to the ERAS program was correlated with outcome and time of discharge. Methods A prospective, observational, multicenter study was designed to be performed at Italian referral centers for gastric surgery. The protocol was discussed and approved by the Italian Research Group on Gastric Cancer. Twentythree ERAS domains were applied. A multivariate logistic regression was used to assess the association between ERAS compliance and overall and major complication rates. The Poisson regression model (measured as mean ratios) was used to assess the association of ERAS compliance rate and length of stay (LOS). Results Eight centers participated and 290 subjects with a median age of 73 years were enrolled. The overall rates of adherence to pre-, intra-, and postoperative ERAS items were 69.8%, 60.3%, and 82.5%, respectively. At the multivariate model, there was an association between overall rate of morbidity and an overall ERAS compliance rate greater than 70% (OR 0.413; 95% CI 0.235-0.7240; P 0.002). A similar association was found for major complications (OR 0.328; 95% CI 0.151-0.709; P 0.005). The Poisson regression showed that in patients with ERAS compliance rate [70%, LOS was reduced of approximately 20% (mean ratio 0.812; 95% CI 0.694-0.950; P 0.009). Conclusions These results suggest a moderate compliance to an ERAS program and a significant association between adherence and outcomes.Luca Gianotti and Uberto Fumagalli Romario have equally contributed to first authorship.

The impact of body mass index (BMI) on postoperative outcomes after curative resection for esophageal cancer has been assessed in many studies worldwide with conflicting conclusions. The aim of this meta-analysis is to evaluate the influence of preoperative BMI on surgical and oncologic outcomes after radical surgery for esophageal cancer, in Western studies. A comprehensive electronic search was performed to identify Western publications reporting BMI and outcomes following surgery for esophageal cancer. Articles that did not report preoperative BMI, postoperative morbidity, and early mortality were excluded. Statistical analysis was performed using the OpenMetaAnalyst software (Version 10.10). One hundred and ninety records were examined and 8 studies were included with a total of 2838 patients. The study population was stratified into two groups: a nonobese group (BMI < 30 kg/m2), containing 2199 patients, and an obese group (BMI ≥ 30 kg/m2), with 639 patients. In the obese group, there was an increased risk (up to 35%) of anastomotic leak (P = 0.003; RR: 0.857, 95% CI: 0.497, 0.867). The obese group showed a significantly more favorable five-year overall survival (P = 0.011). Although there was a significant association between anastomotic leak and obesity, patients with obesity also have a better overall 5-year survival. This meta-analysis demonstrates that patients with obesity should be counseled regarding the specific risks of surgery but they can be reassured that despite these risks overall outcome is satisfactory.

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Background Data on ERAS for gastrectomy are scarce, and the majority of the studies come from Eastern countries. Patients in the West are older and suffer from more advanced tumors that impair their clinical condition and often require neoadjuvant treatment. This retrospective study assessed the feasibility and safety of an Enhanced Recovery After Surgery (ERAS) protocol for gastrectomy in a Western center. Methods We conducted a single-center study of 351 patients operated for gastric cancer: 103, operated from January 2015 to December 2016, followed the standard pathway, while 248, operated from January 2017 to December 2019, followed the ERAS program. The primary outcomes considered were length of hospital stay (LOS) and direct costs. Secondary outcomes were 90-day morbidity and mortality, readmission rate, and compliance with ERAS items. A propensity score (PS) was built on confounding variables. Results Compliance with ERAS items after the program was ≥ 70%. Univariable analysis evidenced a 2-day median reduction in LOS and a median cost reduction of €826 per patient in the ERAS group. PS-based multivariable analysis confirmed a significant, 2-day decrease in median LOS and a €1097 saving after ERAS introduction. Ninety-day mortality decreased slightly in ERAS group, while complications and readmissions did not change significantly. When complications were included in the multivariable analysis, ERAS retained its significance, although the effects on LOS and cost were blunted to a median reduction of 1 day and €775, respectively. Conclusions ERAS for gastrectomy improved patients’ recovery and reduced hospital costs without changes in morbidity, mortality, or readmission.

Gastric cancer with Laurèn diffuse types is increasing in the West. The raising trend is more evident when considering signet ring cells (SRC) histology. However, to control the biologic potential of this GC subtype, some hypotheses of tailored therapeutic strategies for SRC cancers have been made. A review of the literature was performed using the key words "signet ring cells" AND "gastric cancer". Results of literature review were descriptively reported. Endoscopic submucosal dissection (ESD), according to the Japanese extended criteria, could be a therapeutic option for early SRC tumours. However, according to the evidences from more recent studies, indications for ESD to these tumours types should be carefully considered. Concerning the optimal surgical treatment, considering the high lymphotropism and infiltrating behaviour of SRC histotype, the extension of gastric resection should be wider than for intestinal type cancer and laparoscopic surgery should be performed carefully. Moreover, D3 lymphadenectomy could provide a benefit in diffuse-type and SRC histology. The role of surgery in gastric cancer with peritoneal carcinomatosis is still debated and studies on this topic should stratify the good results according to GC histotype. Finally, despite the evidences of chemoresistance in SRC, ongoing randomized trials suggest that multimodal therapy could be the best treatment. Based on the assumption that SRC tumours have specific features, they deserve a specific multimodal treatment. However, a preliminary step to generate strong evidences in this field is the standardization of terminology used to define signet ring cells carcinoma.

Background and ObjectiveThe aim of this study was to assess the ability of Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography (18F-FDG PET/CT) to provide functional information useful in predicting pathological response to an intensive neoadjuvant chemo-radiotherapy (nCRT) protocol for both esophageal squamous cell carcinoma (SCC) and adenocarcinoma (ADC) patients.Material and MethodsEsophageal carcinoma (EC) patients, treated in our Center between 2014 and 2018, were retrospectively reviewed. The nCRT protocol schedule consisted of an induction phase of weekly administered docetaxel, cisplatin, and 5-fluorouracil (TCF) for 3 weeks, followed by a concomitant phase of weekly TCF for 5 weeks with concurrent radiotherapy (50–50.4 Gy in 25–28 fractions). Three 18F-FDG PET/CT scans were performed: before (PET1) and after (PET2) induction chemotherapy (IC), and prior to surgery (PET3). Correlation between PET parameters [maximum and mean standardized uptake value (SUVmax and SUVmean), metabolic tumor volume (MTV), and total lesion glycolysis (TLG)], radiomic features and tumor regression grade (TGR) was investigated.ResultsFifty-four patients (35 ADC, 19 SCC; 48 cT3/4; 52 cN+) were eligible for the analysis. Pathological response to nCRT was classified as major (TRG1-2, 41/54, 75.9%) or non-response (TRG3-4, 13/54, 24.1%). A major response was statistically correlated with SCC subtype (p = 0.02) and smaller tumor length (p = 0.03). MTV and TLG measured prior to IC (PET1) were correlated to TRG1-2 response (p = 0.02 and p = 0.02, respectively). After IC (PET2), SUVmean and TLG correlated with major response (p = 0.03 and p = 0.04, respectively). No significance was detected when relative changes of metabolic parameters between PET1 and PET2 were evaluated. At textural quantitative analysis, three independent radiomic features extracted from PET1 images ([JointEnergy and InverseDifferenceNormalized of GLCM and LowGrayLevelZoneEmphasis of GLSZM) were statistically correlated with major response (p &lt; 0.0002).Conclusions18F-FDG PET/CT traditional metrics and textural features seem to predict pathologic response (TRG) in EC patients treated with induction chemotherapy followed by neoadjuvant chemo-radiotherapy. Further investigations are necessary in order to obtain a reliable predictive model to be used in the clinical practice.

Docetaxel associated with oxaliplatin and 5-fluorouracil (FLOT) has been reported as the best perioperative treatment for gastric cancer. However, there is still some debate about the most appropriate number and timing of chemotherapy cycles. In this randomized multicenter phase II study, patients with resectable gastric cancer were staged through laparoscopy and peritoneal lavage cytology, and randomly assigned (1:1) to either four cycles of neoadjuvant chemotherapy (arm A) or two preoperative + two postoperative cycles of docetaxel, oxaliplatin, and capecitabine (DOC) chemotherapy (arm B). The primary endpoint was to assess the percentage of patients receiving all the planned preoperative or perioperative chemotherapeutic cycles. Ninety-one patients were enrolled between September 2010 and August 2016. The treatment was well tolerated in both arms. Thirty-three (71.7%) and 24 (53.3%) patients completed the planned cycles in arms A and B, respectively (p = 0.066), reporting an odds ratio for early interruption of treatment of 0.45 (95% confidence interval (CI): 0.18–1.07). Resection was curative in 39 (88.6%) arm A patients and 35 (83.3%) arm B patients. Five-year progression-free survival (PFS) was 51.2% (95% CI: 34.2–65.8) in arm A and 40.3% (95% CI: 28.9–55.2) in arm B (p = 0.300). Five-year survival was 58.5% (95% CI: 41.3–72.2) and 53.9% (95% CI: 35.5–69.3) (p = 0.883) in arms A and B, respectively. The planned treatment was more frequently completed and was more active, albeit not significantly, in the neoadjuvant arm than in the perioperative group.