International External Validation of Risk Prediction Model of 90-Day Mortality after Gastrectomy for Cancer Using Machine Learning.

BACKGROUND: Radical gastrectomy remains the main treatment for gastric cancer, despite its high mortality. A clinical predictive model of 90-day mortality (90DM) risk after gastric cancer surgery based on the Spanish EURECCA registry database was developed using a matching learning algorithm. We performed an external validation of this model based on data from an international multicenter cohort of patients. METHODS: A cohort of patients from the European GASTRODATA database was selected. Demographic, clinical, and treatment variables in the original and validation cohorts were compared. The performance of the model was evaluated using the area under the curve (AUC) for a random forest model. RESULTS: The validation cohort included 2546 patients from 24 European hospitals. The advanced clinical T- and N-category, neoadjuvant therapy, open procedures, total gastrectomy rates, and mean volume of the centers were significantly higher in the validation cohort. The 90DM rate was also higher in the validation cohort (5.6%) vs. the original cohort (3.7%). The AUC in the validation model was 0.716. CONCLUSION: The externally validated model for predicting the 90DM risk in gastric cancer patients undergoing gastrectomy with curative intent continues to be as useful as the original model in clinical practice.

Circulating tumor DNA in patients with locally advanced rectal cancer treated with multimodal treatment.

Background: The management of locally advanced rectal cancer (LARC) relies on a multimodal approach. Neither instrumental work-up nor molecular biomarkers are currently available to identify a risk-adapted strategy. Objectives: We aim to investigate the role of circulating tumor DNA (ctDNA) and its clearance at different timepoints during chemo-radiotherapy (CRT) and correlate them with clinical outcomes. Design: Between November 2014 and November 2019, we conducted a monocentric prospective observational study enrolling consecutive patients with LARC managed with neoadjuvant standard CRT (capecitabine and concomitant pelvic long-course radiotherapy), followed by consolidation capecitabine in selected cases and surgery. Methods: Blood samples for ctDNA were obtained at pre-planned timepoints. We evaluated the correlation of baseline variant allele frequency (VAF) with pathologic complete response (pCR) down-staging, node regression (pN0), event-free survival (EFS), and overall survival (OS). Results: Among 112 screened patients, 61 were enrolled. In all, 38 (62%) had a positive ctDNA at baseline with VAF > 0 and 23 had negative ctDNA (VAF = 0). Among patients with negative ctDNA, 30% had a complete response, while only 13% of positive ctDNA patients had pCR [odds ratio (OR) 0.35 (95% confidence interval (CI): 0.10-1.26), p = 0.11]. Similarly, 96% and 74% of pN0 were observed among negative and positive ctDNA patients, respectively [OR 0.13 (95% CI: 0.02-1.07), p = 0.058]. The presence of a baseline VAF > 0 was associated with a trend toward a lower EFS compared with VAF = 0 patients [hazard ratio (HR) = 2.30, 95% CI: 0.63-8.36, p = 0.21]. Within the limitations of small sample size, no difference in OS was observed according to the baseline ctDNA status (HR = 1.18, 95% CI: 0.35-4.06, p = 0.79). Conclusion: Within the limitations of a reduced number of patients, patients with baseline negative ctDNA seem to show a higher probability of pN0 status and a trend toward improved EFS. Prospective translational studies are required to define the role of ctDNA analysis in the multimodal treatment of LARC.

Differences in the molecular organisation of tumours along the colon are linked to interactions within the tumour ecosystem.

Tumours exhibit significant heterogeneity in their molecular profiles across patients, largely influenced by the tissue of origin, where certain driver gene mutations are predominantly associated with specific cancer types. Here, we unveil an additional layer of complexity: some cancer types display anatomic location-specific mutation profiles akin to tissue-specificity. To better understand this phenomenon, we concentrate on colon cancer. While prior studies have noted changes of the frequency of molecular alterations along the colon, the underlying reasons and whether those changes occur rather gradual or are distinct between the left and right colon, remain unclear. Developing and leveraging stringent statistical models on molecular data from 522 colorectal tumours from The Cancer Genome Atlas, we reveal disparities in molecular properties between the left and right colon affecting many genes. Interestingly, alterations in genes responsive to environmental cues and properties of the tumour ecosystem, including metabolites which we quantify in a cohort of 27 colorectal cancer patients, exhibit continuous trends along the colon. Employing network methodologies, we uncover close interactions between metabolites and genes, including drivers of colon cancer, showing continuous abundance or alteration profiles. This underscores how anatomic biases in the composition and interactions within the tumour ecosystem help explaining gradients of carcinogenesis along the colon.

Textbook Neoadjuvant Outcome-Novel Composite Measure of Oncological Outcomes among Gastric Cancer Patients Undergoing Multimodal Treatment.

The incidence of gastric cancer (GC) is expected to increase to 1.77 million cases by 2040. To improve treatment outcomes, GC patients are increasingly treated with neoadjuvant chemotherapy (NAC) prior to curative-intent resection. Although NAC enhances locoregional control and comprehensive patient care, survival rates remain poor, and further investigations should establish outcomes assessment of current clinical pathways. Individually assessed parameters have served as benchmarks for treatment quality in the past decades. The Outcome4Medicine Consensus Conference underscores the inadequacy of isolated metrics, leading to increased recognition and adoption of composite measures. One of the most simple and comprehensive is the "All or None" method, which refers to an approach where a specific set of criteria must be fulfilled for an individual to achieve the overall measure. This narrative review aims to present the rationale for the implementation of a novel composite measure, Textbook Neoadjuvant Outcome (TNO). TNO integrates five objective and well-established components: Treatment Toxicity, Laboratory Tests, Imaging, Time to Surgery, and Nutrition. It represents a desired, multidisciplinary care and hospitalization of GC patients undergoing NAC to identify the treatment- and patient-related data required to establish high-quality oncological care further. A key strength of this narrative review is the clinical feasibility and research background supporting the implementation of the first and novel composite measure representing the "ideal" and holistic care among patients with locally advanced esophago-gastric junction (EGJ) and GC in the preoperative period after NAC. Further analysis will correlate clinical outcomes with the prognostic factors evaluated within the TNO framework.

Multicenter study on the incidence and treatment of mediastinal leaks after esophagectomy (MuMeLe 2).

BACKGROUND: Management of mediastinal anastomotic leaks (MALs) after Ivor Lewis esophagectomy includes conservative, endoscopic, or surgical management. Endoscopic vacuum therapy (EVAC) is becoming a routine approach for MALs, although the outcomes have not been defined. This study aimed to describe the incidence, treatment, and outcomes of MALs in patients who underwent esophagectomy in 3 Italian high-volume centers that routinely use EVAC for MAL. METHODS: Patients who underwent Ivor Lewis esophagectomy between September 2018 and March 2023 were included. RESULTS: A total of 681 patients underwent Ivor Lewis esophagectomy, of whom 88 had MAL. The MAL rates for open, minimally invasive, and robotic esophagectomies were 11.5%, 13.4%, and 14.8%, respectively. Global and specific 30- and 90-day mortality rates for MAL were 0.9% and 2.1% and 6.8% and 15.9%, respectively. Nonoperative management (NOM) as the primary treatment was chosen for 62 patients. EVAC was the most common NOM (62.9%), and the most common operative management (OM) was anastomotic redo (53.8%). Diversion was the OM for 7 patients, of whom 3 patients died. Primary treatment proved successful in 40 patients. Among them, EVAC alone was successful in 35.9% of patients. Globally, endoscopic treatment, including EVAC, was successful in 79.0% of NOM and 55.7% of MALs. NOM and OM were chosen as secondary treatments for 27 and 10 patients, respectively. Secondary treatment proved successful in 21 patients. CONCLUSION: The incidence of MALs after Ivor Lewis esophagectomy is approximately 13%. Endoscopic techniques have a success rate of almost 80%, with EVAC representing a significant part of this treatment process.

Radio-Guided Surgery with a New-Generation ß-Probe for Radiolabeled Somatostatin Analog, in Patients with Small Intestinal Neuroendocrine Tumors.

BACKGROUND: Radio-guided surgery (RGS) holds promise for improving surgical outcomes in neuroendocrine tumors (NETs). Previous studies showed low specificity (SP) using γ-probes to detect radiation emitted by radio-labeled somatostatin analogs. OBJECTIVE: We aimed to assess the sensitivity (SE) and SP of the intraoperative RGS approach using a ß-probe with a per-lesion analysis, while assessing safety and feasibility as secondary objectives. METHODS: This prospective, single-arm, single-center, phase II trial (NCT05448157) enrolled 20 patients diagnosed with small intestine NETs (SI-NETs) with positive lesions detected at 68Ga-DOTA-TOC positron emission tomography/computed tomography (PET/CT). Patients received an intravenous injection of 1.1 MBq/Kg of 68Ga-DOTA-TOC 10 min prior to surgery. In vivo measurements were conducted using a ß-probe. Receiver operating characteristic (ROC) analysis was performed, with the tumor-to-background ratio (TBR) as the independent variable and pathology result (cancer vs. non-cancer) as the dependent variable. The area under the curve (AUC), optimal TBR, and absorbed dose for the surgery staff were reported. RESULTS: The intraoperative RGS approach was feasible in all cases without adverse effects. Of 134 specimens, the AUC was 0.928, with a TBR cut-off of 1.35 yielding 89.3% SE and 86.4% SP. The median absorbed dose for the surgery staff was 30 µSv (range 12-41 µSv). CONCLUSION: This study reports optimal accuracy in detecting lesions of SI-NETs using the intraoperative RGS approach with a novel ß-probe. The method was found to be safe, feasible, and easily reproducible in daily clinical practice, with minimal radiation exposure for the staff. RGS might potentially improve radical resection rates in SI-NETs. CLINICAL TRIALS REGISTRATION: 68Ga-DOTATOC Radio-Guided Surgery with ß-Probe in GEP-NET (RGS GEP-NET) [NCT0544815; https://classic. CLINICALTRIALS: gov/ct2/show/NCT05448157 ].

Roux-en-Y with or without jejunal J-pouch reconstruction after total gastrectomy for gastric cancer: systematic review and meta-analysis of long-term functional outcomes.

BACKGROUND: Increased survival of patients undergoing total gastrectomy for gastric cancer has prompted several efforts to improve long-term postgastrectomy syndrome (PGS) outcomes. Whether a J-pouch (JP) reconstruction may be more beneficial than a standard Roux-en-Y (RY) is controversial. METHODS: A systematic review with meta-analysis was conducted, including studies reporting long-term outcomes of patients treated with total gastrectomy and JP vs RY esophagojejunostomy for gastric adenocarcinoma. A literature search was performed on PubMed, Scopus, and Google Scholar. Primary endpoints were symptom control, weight loss, eating capacity (EC), and quality of life (QoL) with at least 6 months of follow-up. Safety endpoints were explored. RESULTS: Overall, 892 patients were included from 15 studies (6 randomized controlled trials [RCTs] and 9 non-RCTs): 452 (50.7%) in the JP group and 440 (49.3%) in the RY group. Compared with RY, JP showed a significantly lower rate of dumping syndrome (13.8% vs 26.9%, odds ratio [OR], 0.29; 95% confidence interval [CI], 0.14-0.58; P < .001; I2 = 22%) and heartburn symptoms (20.4% vs 39.0%; OR, 0.29; 95% CI, 0.14-0.64; P = .002; I2 = 0%). Reflux (OR, 0.61; 95% CI, 0.28-1.32; P = .21; I2 = 42%) and epigastric fullness (OR, 0.60; 95% CI, 0.18-2.05; P = .41; I2 = 69%) were similar in both groups. Weight loss and EC were similar between the groups. QoL outcome seemed to be burdened by bias. There was no difference in morbidity, mortality, and anastomotic leak rate between groups. Operative time was significantly longer for JP than for RY (271.9 vs 251.6 minutes, respectively; mean difference, 21.55; 95% CI, 4.64-38.47; P = .01; I2 = 96%). CONCLUSION: JP reconstruction after total gastrectomy for gastric cancer is as safe as RY and may provide an advantage in postgastrectomy dumping syndrome and heartburn symptoms.

Diagnosis and staging of small intestinal neuroendocrine tumors with CT enterography and PET with Gallium-68: preoperative risk stratification protocol.

PURPOSE: Pre-operative diagnosis and staging of small intestine neuroendocrine tumors (SI-NETs) remain sub-optimal, with open palpation during surgery still considered the gold standard. This limits a standardized implementation of minimally invasive surgery (MIS). The aim of this single-center retrospective study was to assess a tailored diagnostic work-up to identify candidates at low risk of undetected disease who may benefit from MIS. METHODS: Patients diagnosed with SI-NETs between 2013 and 2022 who underwent contrast-enhanced computed tomography enterography (CTE) and Ga68-DOTATOC-positron emission tomography-CT (68 Ga DOTATATE PET/CT) preoperatively and subsequently underwent open surgical resection were included. Imaging studies were reassessed by two radiologists. Combined use of CTE and 68 Ga DOTATATE PET/CT in determining primary lesion disease burden (number of lesions) and LN disease stage (distal and proximal relative to superior mesenteric vessels) was assessed, using surgical reports and pathology as gold standard. RESULTS: Overall, 56 patients were included. Sensitivity of CTE and 68 Ga DOTATATE PET/CT for at least one primary SI-NET was 100% and 94%, respectively. In the presence of concordance between studies, combined use of CTE and 68 Ga DOTATATE PET/CT for detection of single primary tumors improved specificity to 89% (n = 25/28) with a positive predictive value of 87.5% (n = 21/24). Distal LN disease was identified in 89.2% of cases (n = 33/37). The association of single lesion and distal LN disease was found pre-operatively in 32% of patients (n = 18). CONCLUSION: Combined use of CTE and 68 Ga DOTATATE PET/CT enables identifying low-risk surgical candidates (single SI-NET lesions with distal LN disease).

Biological and targeting differences between the rare KRAS A146T and canonical KRAS mutants in gastric cancer models.

BACKGROUND: Gastric cancer (GC) is the third leading cause of cancer-related death worldwide, with a poor prognosis for patients with advanced disease. Since the oncogenic role of KRAS mutants has been poorly investigated in GC, this study aims to biochemically and biologically characterize different KRAS-mutated models and unravel differences among KRAS mutants in response to therapy. METHODS: Taking advantage of a proprietary, molecularly annotated platform of more than 200 GC PDXs (patient-derived xenografts), we identified KRAS-mutated PDXs, from which primary cell lines were established. The different mutants were challenged with KRAS downstream inhibitors in in vitro and in vivo experiments. RESULTS: Cells expressing the rare KRAS A146T mutant showed lower RAS-GTP levels compared to those bearing the canonical G12/13D mutations. Nevertheless, all the KRAS-mutated cells displayed KRAS addiction. Surprisingly, even if the GEF SOS1 is considered critical for the activation of KRAS A146T mutants, its abrogation did not significantly affect cell viability. From the pharmacologic point of view, Trametinib monotherapy was more effective in A146T than in G12D-mutated models, suggesting a vulnerability to MEK inhibition. However, in the presence of mutations in the PI3K pathway, more frequently co-occurrent in A146T models, the association of Trametinib and the AKT inhibitor MK-2206 was required to optimize the response. CONCLUSION: A deeper genomic and biological characterization of KRAS mutants might sustain the development of more efficient and long-lasting therapeutic options for patients harbouring KRAS-driven GC.

Textbook outcome as indicator of surgical quality in a single Western center: results from 300 consecutive gastrectomies.

Textbook outcome (TO) has been proposed as a tool to evaluate surgical quality. Textbook oncological outcome (TOO) adds chemotherapeutic compliance to TO. This study was conducted to analyze the TO and TOO of patients with gastric adenocarcinoma who underwent surgery at our center. Data from a prospective database of patients operated on for gastric adenocarcinoma between September 2018 and September 2022 were analyzed. Postoperative management followed Enhanced Recovery After Surgery guidelines. The Dutch Upper Gastrointestinal Cancer Audit group defined TO as a multidimensional measure (10 items). TOO also considers guideline-accordant chemotherapeutic compliance. Three hundred patients underwent surgery during the study period (167 men, 133 women). One hundred seventy-six (58.7%) reached TO. Achieving TO was influenced by patients' comorbidities, calculated via the Charlson Comorbidity Score (3 vs. 4; p = 0.002) and surgery type (subtotal gastrectomy; p < 0.001), but not by the American Society of Anesthesiologists (ASA) score (p = 0.057) or surgical approach (laparoscopic vs. open; p = 0.208). The analysis of TOO included 213 patients. Of these, 71 (33%) underwent complete adequate systemic treatment. Compared with the non-TOO group, patients who achieved TOO had a lower median age (64 vs. 73 years; p < 0.001) and lower ASA score (p < 0.001) and more frequently underwent preoperative chemotherapy (p < 0.001). Our results represent the experience of a single team at a high-volume Western institute. Patients' comorbidities and surgery type influenced whether TO was achieved. Conversely, younger age, lower ASA score and preoperative chemotherapy were associated with TOO.

Oligometastatic Gastric Cancer: Clinical Data from the Meta-Gastro Prospective Register of the Italian Research Group on Gastric Cancer.

BACKGROUND: Interest in the field of metastatic gastric cancer has grown in recent years, and the identification of oligometastatic patients plays a critical role as it consents to their inclusion in multimodal treatment strategies, which include systemic therapy but also surgery with curative intent. To collect sound clinical data on this subject, The Italian Research Group on Gastric Cancer developed a prospective multicentric observational register of metastatic gastric cancer patients called META-GASTRO. METHODS: Data on 383 patients in Meta-Gastro were mined to help our understanding of oligometastatic, according to its double definition: quantitative/anatomical and dynamic. RESULTS: the quantitative/anatomical definition applies to single-site metastases independently from the metastatic site (p < 0.001) to peritoneal metastases with PCI ≤ 12 (p = 0.009), to 1 or 2 hepatic metastases (p = 0.024) and nodal metastases in station 16 (p = 0.002). The dynamic definition applies to a percentage of cases variable according to the metastatic site: 8%, 13.5 and 23.8% for hepatic, lymphatic and peritoneal sites, respectively. In all cases, the OS of patients benefitting from conversion therapy was similar to those of cases deemed operable at diagnosis and operated after neoadjuvant chemotherapy. CONCLUSIONS: META-GASTRO supports the two-fold definition of oligometastatic gastric cancer: the quantitative/anatomical one, which accounts for 30% of our population, and the dynamic one, observed in 16% of our cases.