Active surveillance of oesophageal cancer after response to neoadjuvant chemoradiotherapy: dysphagia is uncommon.

BACKGROUND: Active surveillance is being investigated as an alternative to standard surgery after neoadjuvant chemoradiotherapy for oesophageal cancer. It is unknown whether dysphagia persists or develops when the oesophagus is preserved after neoadjuvant chemoradiotherapy. The aim of this study was to assess the prevalence and severity of dysphagia during active surveillance in patients with an ongoing response. METHODS: Patients who underwent active surveillance were identified from the Surgery As Needed for Oesophageal cancer ('SANO') trial. Patients without evidence of residual oesophageal cancer until at least 6 months after neoadjuvant chemoradiotherapy were included. Study endpoints were assessed at time points that patients were cancer-free and remained cancer-free for the next 4 months. Dysphagia scores were evaluated at 6, 9, 12, and 16 months after neoadjuvant chemoradiotherapy. Scores were based on the European Organisation for Research and Treatment of Cancer oesophago-gastric quality-of-life questionnaire 25 (EORTC QLQ-OG25) (range 0-100; no to severe dysphagia). The rate of patients with a (non-)traversable stenosis was determined based on all available endoscopy reports. RESULTS: In total, 131 patients were included, of whom 93 (71.0 per cent) had adenocarcinoma, 93 (71.0 per cent) had a cT3-4a tumour, and 33 (25.2 per cent) had a tumour circumference of greater than 75 per cent at endoscopy; 60.8 to 71.0 per cent of patients completed questionnaires per time point after neoadjuvant chemoradiotherapy. At all time points after neoadjuvant chemoradiotherapy, median dysphagia scores were 0 (interquartile range 0-0). Two patients (1.5 per cent) underwent an intervention for a stenosis: one underwent successful endoscopic dilatation; and the other patient required temporary tube feeding. Notably, these patients did not participate in questionnaires. CONCLUSION: Dysphagia and clinically relevant stenosis are uncommon during active surveillance.

The clinical impact of testing for biomarkers in gastric cancer patients: a real-world cohort.

BACKGROUND AND AIMS: In gastric cancer (GC), HER2 was the first biomarker for guided therapy registered for clinical use. Considering the recent approvals of immune check-point blockade (ICB) in gastro-oesophageal cancers, testing for mismatch repair deficiency (dMMR), Epstein-Barr virus (EBV) and PD-L1 combined positive score (CPS) is becoming increasingly important. Here we describe a real-world cohort on biomarker assessment in GC patients. METHODS: Patients diagnosed with GC between 2017 and 2021 were included. Biomarker results were retrieved from electronic patient files. PD-L1 CPS was determined retrospectively on dMMR and EBV-positive (EBV+) tumours. Data on genomic sequencing were analysed separately. RESULTS: Of 363 patients identified, 45% had metastatic disease. In 335 patients (92%) at least one biomarker was tested. The prevalence of HER2+, dMMR and EBV+ tumours was 10% (32 of 319), 7% (20 of 294) and 1% (three of 235), respectively. Of the dMMR and EBV+ tumours, 95% had a PD-L1 CPS ≥ 5. Therapeutic strategy was adjusted in 31 of 55 patients and consisted of anti-HER2 therapies as well as ICB in clinical trials. Genomic alterations were found in 44 of 60 tested patients. TP53 (73%) and PIK3CA (20%) mutations were most common, followed by KRAS mutations (11%) and amplifications (11%). CONCLUSIONS: In this real-world cohort, testing for HER2, dMMR and EBV status affected treatment decisions in 56% of the patients. Although most dMMR and EBV+ tumours had a PD-L1 CPS ≥ 5, not all patients with a high probability of treatment response are identified. Based on these results, a stepwise diagnostic strategy is proposed.

Intensive endoscopic therapy for untreated cervical anastomotic strictures after esophagectomy: a pilot study.

BACKGROUND: Cervical anastomotic strictures after esophagectomy cause significant disease burden. We aimed to study the technical feasibility and safety of intensive endoscopic therapy. METHODS: In this pilot study, we included 15 patients with an untreated benign cervical anastomotic stricture after esophagectomy. Intensive endoscopic therapy comprised three endoscopic modalities: in- and excision using a needle-knife, intralesional steroid injections and bougie dilation. In two endoscopic procedures, the stricture was dilated up to a luminal diameter of 18 mm. Patients were followed up to 6 months. RESULTS: A luminal diameter of 18 mm was achieved in 13 of 15 patients (87%) after two endoscopic procedures. No major adverse events related to the investigational treatment occurred. Median dysphagia scores significantly improved from 2 (IQR, interquartile range, 2-3) at baseline to 0 (IQR 0-1) after 14 days (p < 0.001). Eleven (73%) patients developed recurrent symptoms of dysphagia requiring a median of 1 (IQR 0-3) additional endoscopic dilation procedure. CONCLUSIONS: Achieving a luminal diameter of 18 mm in two procedures with intensive endoscopic therapy was technically feasible and effective in reducing dysphagia rapidly in patients with a cervical anastomotic stricture after esophagectomy. No major adverse events related to the investigational treatment were observed.

First estimates of diffuse gastric cancer risks for carriers of CTNNA1 germline pathogenic variants.

BACKGROUND: Pathogenic variants (PV) of CTNNA1 are found in families fulfilling criteria for hereditary diffuse gastric cancer (HDGC) but no risk estimates were available until now. The aim of this study is to evaluate diffuse gastric cancer (DGC) risks for carriers of germline CTNNA1 PV. METHODS: Data from published CTNNA1 families were updated and new families were identified through international collaborations. The cumulative risk of DGC by age for PV carriers was estimated with the genotype restricted likelihood (GRL) method, taking into account non-genotyped individuals and conditioning on all observed phenotypes and genotypes of the index case to obtain unbiased estimates. A non-parametric (NP) and the Weibull functions were used to model the shape of penetrance function with the GRL. Kaplan-Meier incidence curve and standardised incidence ratios were also computed. A 'leave-one-out' strategy was used to evaluate estimate uncertainty. RESULTS: Thirteen families with 46 carriers of PV were included. The cumulative risks of DGC at 80 years for carriers of CTNNA1 PV are 49% and 57%, respectively with the Weibull GRL and NP GRL methods. Risk ratios to population incidence reach particularly high values at early ages and decrease with age. At 40 years, they are equal to 65 and 833, respectively with the Weibull GRL and NP GRL. CONCLUSION: This is the largest series of CTNNA1 families that provides the first risk estimates of GC. These data will help to improve management and surveillance for these patients and support inclusion of CTNNA1 in germline testing panels.

High CD8+ tumour-infiltrating lymphocyte density associates with unfavourable prognosis in oesophageal adenocarcinoma following poor response to neoadjuvant chemoradiotherapy.

AIMS: Determining prognosis following poor response to neoadjuvant chemoradiotherapy (nCRT) in oesophageal adenocarcinoma (OAC) remains challenging. An immunosuppressive tumour microenvironment (TME) as well as immune infiltrate density and composition are considered to play a critical role in the immune interaction between host and tumour and can predict therapy response and survival in many cancers, including gastrointestinal malignancies. The aim of this study was to establish the TME characteristics associated with survival following a poor response to nCRT. METHODS AND RESULTS: The prognostic significance of OAC-associated CD3+ , CD4+ , CD8+ , forkhead box protein 3 (FoxP3+ ) and programmed cell death ligand 1 (PD-L1) expression was studied by immunohistochemistry and quantified by automated image analysis in 123 patients who underwent nCRT and curative resection. Results from good and poor responders were contrasted and immune infiltration was related to disease course in both groups. Subsequently a cohort of 57 patients with a moderate response to nCRT was analysed in a similar fashion. Tumour cell percentage positively correlated to immune infiltration markers. In good and moderate responders, none of the immune infiltrate parameters was associated with survival; in poor responders CD8+ was an independent negative predictor of OS in univariate analysis (P = 0.03) and high CD8+ infiltration was associated with worse OS (15 versus 32 months, P = 0.042). CONCLUSION: A high CD8+ density is an independent biomarker of poor OS in poor responders to nCRT, but not in good and moderate responders. Our results suggest that patients with a poor response to nCRT but concomitant high CD8+ counts in the resection specimen require adjuvant therapy.

Motion-compensated FDG PET/CT for oesophageal cancer.

PURPOSE: Respiratory-induced motion of oesophageal tumours and lymph nodes can influence positron-emission tomography/computed tomography (PET/CT). The aim was to compare standard three-dimensional (3D) and motion-compensated PET/CT regarding standardized uptake value (SUV), metabolic tumour volume (MTV) and detection of lymph node metastases. METHODS: This prospective observational study (NCT02424864) included 37 newly diagnosed oesophageal cancer patients. Diagnostic PET/CT was reconstructed in 3D and motion-compensated PET/CT. MTVs of the primary tumour were calculated using an automated region-growing algorithm with SUV thresholds of 2.5 (MTV2.5) and ≥ 50% of SUVmax (MTV50%). Blinded for reconstruction method, a nuclear medicine physician assessed all lymph nodes showing 18F­fluorodeoxyglucose uptake for their degree of suspicion. RESULTS: The mean (95% CI) SUVmax of the primary tumour was 13.1 (10.6-15.5) versus 13.0 (10.4-15.6) for 3D and motion-compensated PET/CT, respectively. MTVs were also similar between the two techniques. Bland-Altman analysis showed mean differences between both measurements (95% limits of agreement) of 0.08 (-3.60-3.75), -0.26 (-2.34-1.82), 4.66 (-29.61-38.92) cm3 and -0.95 (-19.9-18.0) cm3 for tumour SUVmax, lymph node SUVmax, MTV2.5 and MTV50%, respectively. Lymph nodes were classified as highly suspicious (30/34 nodes), suspicious (20/22) and dubious (66/59) for metastases on 3D/motion-compensated PET/CT. No additional lymph node metastases were found on motion-compensated PET/CT. SUVmax of the most intense lymph nodes was similar for both scans: mean (95% CI) 6.6 (4.3-8.8) and 6.8 (4.5-9.1) for 3D and motion-compensated, respectively. CONCLUSION: SUVmax of the primary oesophageal tumour and lymph nodes was comparable on 3D and motion-compensated PET/CT. The use of motion-compensated PET/CT did not improve lymph node detection.

Clinical response assessment on DW-MRI compared with FDG-PET/CT after neoadjuvant chemoradiotherapy in patients with oesophageal cancer.

PURPOSE: In about 30% of patients treated with neoadjuvant chemoradiotherapy (nCRT) followed by surgical resection for locally advanced oesophageal cancer no vital tumour is found in the resection specimen. Accurate clinical response assessment is critical if deferral from surgery is considered in complete responders. Our study aimed to compare the performance of MRI and of FDG-PET/CT for the detection of residual disease after nCRT. METHODS: Patients with oesophageal cancer eligible for nCRT and oesophagectomy were prospectively included. All patients underwent FDG-PET/CT and MRI before and between 6 and 8 weeks after nCRT. Two radiologists scored the MRI scans, and two nuclear medicine physicians scored the FDG-PET/CT scans using a 5-point score for residual disease. Histopathology after oesophagectomy represented the reference standard. Sensitivity, specificity, and area under the receiver operating characteristic curve (AUC) were calculated for detection of residual tumour (ypT+), residual nodal disease (ypN+), and any residual disease (ypT+Nx/ypT0N+). RESULTS: Seven out of 33 (21%) patients had a pathological complete response. The AUCs for individual readers to detect ypT+ were 0.71/0.70 on diffusion-weighted (DW)-MRI and 0.54/0.57 on FDG-PET/CT, and to detect ypN+ were 0.89/0.81 on DW-MRI and 0.75/0.71 on FDG-PET/CT. The AUCs/sensitivities/specificities for the individual readers to detect any residual disease were 0.74/92%/57% and 0.70/96%/43% on MRI; these were 0.49/69%/29% and 0.60/69%/43% on FDG-PET/CT, respectively. CONCLUSION: MRI reached higher diagnostic accuracies than FDG-PET/CT for the detection of residual tumour in oesophageal cancer patients at 6 to 8 weeks after nCRT.

Hereditary diffuse gastric cancer: updated clinical practice guidelines.

Hereditary diffuse gastric cancer (HDGC) is an autosomal dominant cancer syndrome that is characterised by a high prevalence of diffuse gastric cancer and lobular breast cancer. It is largely caused by inactivating germline mutations in the tumour suppressor gene CDH1, although pathogenic variants in CTNNA1 occur in a minority of families with HDGC. In this Policy Review, we present updated clinical practice guidelines for HDGC from the International Gastric Cancer Linkage Consortium (IGCLC), which recognise the emerging evidence of variability in gastric cancer risk between families with HDGC, the growing capability of endoscopic and histological surveillance in HDGC, and increased experience of managing long-term sequelae of total gastrectomy in young patients. To redress the balance between the accessibility, cost, and acceptance of genetic testing and the increased identification of pathogenic variant carriers, the HDGC genetic testing criteria have been relaxed, mainly through less restrictive age limits. Prophylactic total gastrectomy remains the recommended option for gastric cancer risk management in pathogenic CDH1 variant carriers. However, there is increasing confidence from the IGCLC that endoscopic surveillance in expert centres can be safely offered to patients who wish to postpone surgery, or to those whose risk of developing gastric cancer is not well defined.

Gastroscopic surveillance with targeted biopsies compared with random biopsies in CDH1 mutation carriers.

BACKGROUND : The International Gastric Cancer Linkage Consortium (IGCLC) consensus guideline advises prophylactic gastrectomy in early adulthood to prevent gastric cancer development in CDH1 germline mutation carriers; psychosocial reasons may postpone gastrectomy. We analyzed the yield of signet-ring cell carcinoma (SRCC) during surveillance gastroscopy in CDH1 mutation carriers. METHODS : A retrospective analysis on surveillance gastroscopies in CDH1 mutation carriers was performed. The yield of SRCC in both targeted and random biopsies was studied. Endoscopic (biopsy) results were compared with the histopathologic outcomes in gastrectomy specimens. RESULTS : 42 CDH1 mutation carriers (18 men; mean age 43, range 20-82 years) underwent 96 surveillance gastroscopies. SRCC lesions were identified on surveillance gastroscopy in 21 patients (50 %), by either targeted biopsies only (n = 11), random biopsies only (n = 3), or both random and targeted biopsies (n = 7). SRCC was detected in 41 /377 targeted biopsies (11 %), whereas random biopsies revealed SRCC in 14/1563 biopsies (0.9 %). At least one SRCC lesion was found in 26 of 30 gastrectomy specimens. In 18 of these 26 specimens (69 %), SRCC had been identified by endoscopic biopsies. Missed lesions were all small superficial SRCC foci, mainly in the body of the stomach. CONCLUSION : In our cohort of CDH1 mutation carriers, SRCC lesions were identified by an extensive endoscopic surveillance protocol in 69 % of SRCC-positive patients who underwent a gastric resection. The low number of SRCC detected through random sampling demands a critical reappraisal of random biopsy sampling in the IGCLC guideline.

Added value of MRI to endoscopic and endosonographic response assessment after neoadjuvant chemoradiotherapy in oesophageal cancer.

OBJECTIVES: In order to select oesophageal cancer patients after neoadjuvant chemoradiotherapy (nCRT) for organ-preserving treatment instead of surgery, a high diagnostic accuracy is required. The aim of this study was to evaluate whether MRI had additional value to gastroscopy with biopsies and endosonographic ultrasound (EUS) with fine needle aspiration (FNA) for the detection of residual tumour after nCRT. METHODS: Twenty-two patients with oesophageal cancer eligible for nCRT followed by oesophagectomy were prospectively included. All patients underwent (T2- and diffusion-weighted) MRI and gastroscopy+EUS before and after nCRT. Histopathology after oesophagectomy was the reference standard with pathological complete response (pCR) defined as ypT0N0. Diagnostic performance regarding the detection of residual tumour was calculated for gastroscopic biopsies and for EUS-FNA without and with MRI. RESULTS: Nineteen of the 22 patients (86%) did not achieve pCR after nCRT (7 ypT+N+, 11 ypT+N0, 1 ypT0N+). Biopsies detected residual tumour in 6 of 18 ypT+ patients. After adding MRI, 16 of 18 residual tumours were assessed correctly. EUS-FNA detected 3 out of 8 ypN+ patients, while MRI did not improve detection. Overall, adding MRI improved sensitivity for detection of residual tumour to 89% (17 of 19) from 47% (9 of 19) with endoscopic biopsies and EUS-FNA only. CONCLUSION: In this small study, the detection of residual tumour after nCRT in oesophageal cancer patients was improved by the addition of MRI to gastroscopy and EUS. KEY POINTS: • In this small study, the detection of residual tumour after neoadjuvant chemoradiotherapy in oesophageal cancer patients was improved by adding MRI including diffusion-weighted images to gastroscopy and endosonographic ultrasound. • With the addition of MRI assessment to gastroscopy and endosonographic ultrasound, the considerable risk of missing residual tumours decreased from 53 to 11%, while the pitfall was overstaging in one out of three complete responders.

A national study to assess outcomes of definitive chemoradiation regimens in proximal esophageal cancer.

Background: Proximal esophageal cancer (EC) is commonly treated with definitive chemoradiation (CRT). The radiation dose and type of chemotherapy backbone are still under debate. The objective of this study was to compare the treatment outcomes of contemporary CRT regimens.Material and Methods: In this retrospective observational cohort study, we included patients with locally advanced squamous cell cancer of the proximal esophagus, from 11 centers in the Netherlands, treated with definitive CRT between 2004 and 2014. Each center had a preferential CRT regimen, based on cisplatin (Cis) or carboplatin-paclitaxel (CP) combined with low (≤50.4 Gy) or high (>50.4 Gy) dose radiotherapy (RT). Differences in overall survival (OS) between CRT regimens were assessed using a fully adjusted Cox proportional hazards and propensity score (PS) weighted model. Safety profiles were compared using a multilevel logistic regression model.Results: Two hundred patients were included. Fifty-four, 39, 95, and 12 patients were treated with Cis-low-dose RT, Cis-high-dose RT, CP-low-dose RT, and CP-high-dose RT, respectively. Median follow-up was 62.6 months (95% CI: 47.9-77.2 months). Median OS (21.9 months; 95% CI: 16.9-27.0 months) was comparable between treatment groups (logrank p = .88), confirmed in the fully adjusted and PS weighted model (p > .05). Grades 3-5 acute adverse events were less frequent in patients treated with CP-low-dose RT versus Cis-high-dose RT (OR 3.78; 95% CI: 1.31-10.87; p = .01). The occurrence of grades 3-5 late toxicities was not different between treatment groups.Conclusion: Our study was unable to demonstrate a difference in OS between the CRT regimens, probably related to the relatively small sample size. Based on the superior safety profile, carboplatin and paclitaxel-based CRT regimens are preferred in patients with locally advanced proximal EC.

Radiation-induced liver injury mimicking liver metastases on FDG-PET-CT after chemoradiotherapy for esophageal cancer : A retrospective study and literature review.

BACKGROUND: For esophageal cancer patients treated with neoadjuvant chemoradiotherapy (nCRT), restaging using F­18-fluorodeoxyglucose (FDG) positron emission tomography computed tomography (PET-CT) following nCRT can detect interval metastases, including liver metastases, in almost 10% of patients. However, in clinical practice, focal FDG liver uptake, unrelated to liver metastases, is observed after chemoradiotherapy. This radiation-induced liver injury (RILI) can potentially lead to overstaging. METHODS: A systematic search for potential cases of RILI after (chemo)radiotherapy for esophageal cancer was performed in the electronic reports from all PET-CT scans made between 2006 and 2015 in our hospital. Additional data about potential cases were obtained from the electronic medical records. A literature review of RILI was also performed. RESULTS: Of 205 patients undergoing nCRT, 6 cases with localized increased FDG uptake in the caudate or left liver lobe following nCRT for esophageal cancer were identified. None of these patients had signs of liver metastases with additional imaging, during surgery, on biopsy, or during follow-up (range 11-46 months). At our institute, the incidence of RILI after neoadjuvant chemoradiotherapy for esophageal cancer was 3%. In the literature, RILI is described in about 8% of patients at the time of restaging. FDG-avid lesions occur in the high radiation dose area, usually corresponding to the caudate or left liver lobe. CONCLUSIONS: FDG accumulation in the caudate or left liver lobe after CRT in the area that received a high radiation dose may be caused by metastases or RILI. Awareness of the pitfall of high FDG uptake in RILI is crucial to avoid misinterpretation and overstaging.

Outcomes of screening gastroscopy in first-degree relatives of patients fulfilling hereditary diffuse gastric cancer criteria.

BACKGROUND AND AIMS: The aim of this study was to determine the yield of endoscopic screening in first-degree relatives (FDRs) of CDH1-negative hereditary diffuse-type gastric cancer (HDGC) patients. METHODS: In this retrospective observational cohort study, in 2 expert centers in the Netherlands data were collected on FDRs from families fulfilling the international HDGC criteria that underwent endoscopic screening. Extensive inspection of the stomach was performed by gastroscopy, taking random and/or targeted stomach biopsy specimens to identify diffuse-type gastric cancer. RESULTS: Between 2004 and 2016, 90 persons (40% men; mean age, 48 years) from 40 families were offered endoscopic screening. The mean number of endoscopies per person was 3. The mean follow-up time was 46 months and mean endoscopic interval 20 months. Signet ring cell carcinoma foci restricted to the mucosa (pT1a) were identified in 4 persons (4%) from 1 family, which afterward was diagnosed with a germline CTNNA1 mutation. Advanced poorly cohesive gastric carcinoma was diagnosed in 1 person from another family. Intestinal metaplasia was diagnosed in 38 persons (42%) and low-grade dysplasia in 4 persons (4%). Additionally, in 40 persons (44%) scar tissue was observed in the gastric mucosa, which can hinder the endoscopic detection of small white lesions typical for HDGC. CONCLUSIONS: Endoscopic screening in HDGC families without a pathogenic CDH1 mutation may be reasonable, as we detected signet ring cell carcinomas in 6% of persons screened. However, the criteria and frequency of screening may have to be reconsidered.

Tumor-positive peritoneal cytology in patients with gastric cancer is associated with poor outcome: A nationwide study.

BACKGROUND: The clinical significance of tumor-positive peritoneal cytology (CYT+) in gastric cancer (GC) patients is unclear. This nationwide cohort study aimed to i) assess the frequency of cytological analysis at staging laparoscopy; ii) determine the prevalence of CYT+GC; and iii) compare overall survival (OS) in CYT+ patients versus those with (PM+) and those without (PM-) macroscopic peritoneal disease. METHODS: All patients diagnosed with cT1-4, cN0-2 and M0 or synchronous PM GC between 2016-2021 were identified in the Netherlands Cancer Registry database and linked to the nationwide pathology database. RESULTS: A total of 4397 patients was included, of which 40 % underwent cytological assessment following staging laparoscopy (863/1745). The prevalence of CYT+ was 8 %. A total of 69 patients had CYT+(1.6 %), 789 (17.9 %) had PM+ and 3539 (80.5 %) had PM- disease. Hazard ratio for OS in CYT+ versus PM+ was 0.86 (95 %CI 0.64-1.17, p-value=0.338), and in PM- versus PM+0.43 (95 %CI 0.38-0.49, p-value<0.001). No survival difference was found between systemic chemotherapy versus surgical resection in CYT+ patients. DISCUSSION: In this nationwide study, OS for gastric cancer patients with CYT+ was equally unfavorable as for those with PM+ and significantly worse as compared to those with PM-. The optimal treatment strategy has yet to be established.

Treatment patterns and survival outcomes of patients admitted to the intensive care unit due to immune-related adverse events of immune checkpoint inhibitors.

INTRODUCTION: Severe immune-related adverse events (irAEs) due to immune checkpoint inhibitors (ICIs) can lead to admission to the intensive care unit (ICU). In this retrospective study, we determined the incidence, treatment patterns and survival outcomes of this patient population at a comprehensive cancer center. METHODS: All patients admitted to the ICU due to irAEs from ICI treatment between January 2015 and July 2022 were included. Descriptive statistics were reported on patient characteristics and treatment patterns during hospital admission. Overall survival (OS) from the time of ICU discharge to death was estimated using the Kaplan-Meier method. RESULTS: Over the study period, 5561 patients received at least one ICI administration, of which 32 patients (0.6%) were admitted to the ICU due to irAEs. Twenty patients were treated with anti-PD-1 plus anti-CTLA-4 treatment, whereas 12 patients were treated with ICI monotherapy. The type of irAEs were de novo diabetes-related ketoacidosis (n = 8), immune-related gastrointestinal toxicity (n = 8), myocarditis or myositis (n = 10), nephritis (n = 3), pneumonitis (n = 2), and myelitis (n = 1). The median duration of ICU admission was 3 days (interquartile range: 2-6 days). Three patients died during ICU admission. The median OS of the patients who were discharged from the ICU was 18 months (95% confidence interval, 5.0-NA). CONCLUSION: The incidence of irAEs leading to ICU admission in patients treated with ICI was low in this study. ICU mortality due to irAEs was low and a subset of this patient population even had long-term survival.

Improving diagnostic accuracy of identifying gastric cancer patients with peritoneal metastases: tumor-guided cell-free DNA analysis of peritoneal fluid.

Detection of peritoneal dissemination (PD) in gastric cancer (GC) patients remains challenging. The feasibility of tumor-guided cell-free DNA (cfDNA) detection in prospectively collected peritoneal fluid (ascites and peritoneal lavage) was investigated and compared to conventional cytology in 28 patients. Besides conventional cytology, next generation sequencing was performed on primary tumor DNA and cell-free DNA from peritoneal fluid. Patients were retrospectively grouped into: a positive group (with PD) and a negative group (without PD). Detectable mutations were found in the primary tumor of 68% (n = 19). Sensitivity of PD detection by tumor-guided cfDNA analysis was 91%, compared to 64% by conventional cytology. Within the positive group (n = 11), tumor-guided cfDNA was detected in all patients with ascites samples (4/4, 100%) and in 86% (6/7) of the lavage samples, opposed to 4/4 (100%) patients with ascites and 43% (3/7) with lavage by conventional cytology. Within the negative group (n = 8), conventional cytology was negative for all samples. In two patients, tumor-guided cfDNA was detected in peritoneal lavage fluid. Interestingly, these 2 patients developed PD within 6 months, suggesting a prognostic value of tumor-guided cfDNA detection. This study showed that tumor-guided cfDNA detection in peritoneal fluids of GC patients is feasible and superior to conventional cytology in detecting PD.

Neoadjuvant atezolizumab plus chemotherapy in gastric and gastroesophageal junction adenocarcinoma: the phase 2 PANDA trial.

Gastric and gastroesophageal junction (G/GEJ) cancers carry a poor prognosis, and despite recent advancements, most patients die of their disease. Although immune checkpoint blockade became part of the standard-of-care for patients with metastatic G/GEJ cancers, its efficacy and impact on the tumor microenvironment (TME) in early disease remain largely unknown. We hypothesized higher efficacy of neoadjuvant immunotherapy plus chemotherapy in patients with nonmetastatic G/GEJ cancer. In the phase 2 PANDA trial, patients with previously untreated resectable G/GEJ tumors (n = 21) received neoadjuvant treatment with one cycle of atezolizumab monotherapy followed by four cycles of atezolizumab plus docetaxel, oxaliplatin and capecitabine. Treatment was well tolerated. There were grade 3 immune-related adverse events in two of 20 patients (10%) but no grade 4 or 5 immune-related adverse events, and all patients underwent resection without treatment-related delays, meeting the primary endpoint of safety and feasibility. Tissue was obtained at multiple time points, allowing analysis of the effects of single-agent anti-programmed cell death ligand 1 (PD-L1) and the subsequent combination with chemotherapy on the TME. Twenty of 21 patients underwent surgery and were evaluable for secondary pathologic response and survival endpoints, and 19 were evaluable for exploratory translational analyses. A major pathologic response (≤10% residual viable tumor) was observed in 14 of 20 (70%, 95% confidence interval 46-88%) patients, including 9 (45%, 95% confidence interval 23-68%) pathologic complete responses. At a median follow-up of 47 months, 13 of 14 responders were alive and disease-free, and five of six nonresponders had died as a result of recurrence. Notably, baseline anti-programmed cell death protein 1 (PD-1)+CD8+ T cell infiltration was significantly higher in responders versus nonresponders, and comparison of TME alterations following anti-PD-L1 monotherapy versus the subsequent combination with chemotherapy showed an increased immune activation on single-agent PD-1/L1 axis blockade. On the basis of these data, monotherapy anti-PD-L1 before its combination with chemotherapy warrants further exploration and validation in a larger cohort of patients with nonmetastatic G/GEJ cancer. ClinicalTrials.gov registration: NCT03448835 .