Effect of preoperative chemotherapy on the histopathological classification of gastric cancer.

BACKGROUND: In the era of individualized gastric cancer (GC) treatment, accurate determination of histological subtype becomes increasingly relevant. As yet, it is unclear whether preoperative chemotherapy may affect the histological subtype. The aim of this study was to assess concordance in histological subtype between pretreatment biopsies and surgical resection specimens before and after the introduction of perioperative treatment. METHODS: Histological subtype was centrally determined in paired GC biopsies and surgical resection specimens of patients treated with either surgery alone (SA) in the Dutch D1/D2 study or with preoperative chemotherapy (CT) in the CRITICS trial. The histological subtype as determined in the resection specimen was considered the gold standard. Concordance rates and sensitivity and specificity of intestinal, diffuse, mixed, and "other" subtypes of GC were analyzed. RESULTS: In total, 105 and 515 pairs of GC biopsies and resection specimens of patients treated in the SA and CT cohorts, respectively, were included. Overall concordance in the histological subtype was 72% in the SA and 74% in the CT cohort and substantially higher in the diffuse subtype (83% and 86%) compared to the intestinal (70% and 74%), mixed (21% and 33%) and "other" subtypes (54% and 54%). In the SA cohort, sensitivities and specificities were 0.88 and 0.71 in the intestinal, 0.67 and 0.93 in the diffuse, 0.20 and 0.98 in the mixed, and 0.50 and 0.93 in the "other" subtypes, respectively. CONCLUSION: Our results suggest that accurate determination of histological subtype on gastric cancer biopsies is suboptimal but that the impact of preoperative chemotherapy on histological subtype is negligible.

Adjuvant chemotherapy is superior to chemoradiation after D2 surgery for gastric cancer in the per-protocol analysis of the randomized CRITICS trial.

BACKGROUND: The Intergroup 0116 and the MAGIC trials changed clinical practice for resectable gastric cancer in the Western world. In these trials, overall survival improved with post-operative chemoradiotherapy (CRT) and perioperative chemotherapy (CT). Intention-to-treat analysis in the CRITICS trial of post-operative CT or post-operative CRT did not show a survival difference. The current study reports on the per-protocol (PP) analysis of the CRITICS trial. PATIENTS AND METHODS: The CRITICS trial was a randomized, controlled trial in which 788 patients with stage Ib-Iva resectable gastric or esophagogastric adenocarcinoma were included. Before start of preoperative CT, patients from the Netherlands, Sweden and Denmark were randomly assigned to receive post-operative CT or CRT. For the current analysis, only patients who started their allocated post-operative treatment were included. Since it is uncertain that the two treatment arms are balanced in such PP analysis, adjusted proportional hazards regression analysis and inverse probability weighted analysis were used to minimize the risk of selection bias and to estimate and compare overall and event-free survival. RESULTS: Of the 788 patients, 478 started post-operative treatment according to protocol, 233 (59%) patients in the CT group and 245 (62%) patients in the CRT group. Patient and tumor characteristics between the groups before start of the post-operative treatment were not different. After a median follow-up of 6.7 years since the start of post-operative treatment, the 5-year overall survival was 57.9% (95% confidence interval: 51.4% to 64.3%) in the CT group versus 45.5% (95% confidence interval: 39.2% to 51.8%) in the CRT group (adjusted hazard ratio CRT versus CT: 1.62 (1.24-2.12), P = 0.0004). Inverse probability weighted analysis resulted in similar hazard ratios. CONCLUSION: After adjustment for all known confounding factors, the PP analysis of patients who started the allocated post-operative treatment in the CRITICS trial showed that the CT group had a significantly better 5-year overall survival than the CRT group (NCT00407186).

Perioperative Management of Gastric Cancer Patients Treated With (Sub)Total Gastrectomy, Cytoreductive Surgery, and Hyperthermic Intraperitoneal Chemotherapy (HIPEC): Lessons Learned.

BACKGROUND: The PERISCOPE I study was designed to assess the safety and feasibility of (sub)total gastrectomy, cytoreductive surgery (CRS), and hyperthermic intraperitoneal chemotherapy (HIPEC) with oxaliplatin and docetaxel for gastric cancer patients who have limited peritoneal dissemination. The current analysis investigated changes in perioperative management together with their impact on postoperative outcomes. METHODS: Patients with resectable gastric cancer and limited peritoneal dissemination were administered (sub)total gastrectomy, CRS, and HIPEC with oxaliplatin (460 mg/m2) and docetaxel (escalating scheme: 0, 50, 75 mg/m2). Of the 25 patients who completed the study protocol, 14 were treated in the dose-escalation cohort and 11 were treated in the expansion cohort (to optimize perioperative management). RESULTS: A significant proportion of the patients in the dose-escalation cohort (n = 7, 50%) had ileus-related complications. In this cohort, enteral nutrition was started immediately after surgery at 20 ml/h, which was increased on day 1 to meet nutritional needs. In the expansion cohort, enteral nutrition was administered at 10 ml/h until day 3, then restricted to 20 ml/h until day 6, supplemented with total parenteral nutrition to meet nutritional needs. Ileus-related complications occurred for two patients (18%) of the expansion cohort. The intensive care unit (ICU) readmission rate decreased from 50 (n = 7) to 9% (n = 1; p = 0.04). CONCLUSION: The implementation of a strict nutritional protocol during the PERISCOPE I study was associated with a decrease in postoperative complications. Based on these results, a perioperative care path was described for the gastric cancer HIPEC patients in the PERISCOPE II study.

Treatment of PERItoneal disease in Stomach Cancer with cytOreductive surgery and hyperthermic intraPEritoneal chemotherapy: PERISCOPE I initial results.

BACKGROUND: The role of cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy (HIPEC) in gastric cancer is unknown. This non-randomized dose-finding phase I-II study was designed to assess the safety and feasibility of HIPEC, following systemic chemotherapy, in patients with gastric cancer and limited peritoneal dissemination. The maximum tolerated dose of normothermic intraperitoneal docetaxel in combination with a fixed dose of intraperitoneal oxaliplatin was also explored. METHODS: Patients with resectable cT3-cT4a gastric adenocarcinoma with limited peritoneal metastases and/or tumour-positive peritoneal cytology were included. An open HIPEC technique was used with 460 mg/m2 hyperthermic oxaliplatin for 30 min followed by normothermic docetaxel for 90 min in escalating doses (0, 50, 75 mg/m2 ). RESULTS: Between 2014 and 2017, 37 patients were included. Of 25 patients who completed the full study protocol, four were treated at dose level 1 (0 mg/m2 docetaxel), six at dose level 2 (50 mg/m2 ) and four at dose level 3 (75 mg/m2 ). At dose level 3, two dose-limiting toxicities occurred, both associated with postoperative ileus. Thereafter, another 11 patients were treated at dose level 2, with no more dose-limiting toxicities. Based on this, the maximum tolerated dose was 50 mg/m2 intraperitoneal docetaxel. Serious adverse events were scored in 17 of 25 patients. The reoperation rate was 16 per cent (4 of 25) and the treatment-related mortality rate was 8 per cent (2 patients, both in dose level 3). CONCLUSION: Gastrectomy combined with cytoreductive surgery and HIPEC was feasible using 460 mg/m2 oxaliplatin and 50 mg/m2 normothermic docetaxel.

ANTECEDENTES: El papel de la cirugía citorreductora (cytoreductive surgery, CRS) combinado con la quimioterapia intraperitoneal hipertérmica (hyperthermic intraperitoneal chemotherapy, HIPEC) en el cáncer gástrico no está definido. Este estudio fase I-II no aleatorizado de escalado de dosis fue diseñado para evaluar la seguridad y la viabilidad de HIPEC, después de la quimioterapia sistémica, en pacientes con cáncer gástrico con diseminación peritoneal limitada. Además, se exploró la máxima dosis tolerada (maximum tolerated dose, MTD) de docetaxel intraperitoneal normotérmico en combinación con una dosis fija de oxaliplatino intraperitoneal. MÉTODOS: Se incluyeron pacientes con adenocarcinoma gástrico cT3-cT4a resecable con metástasis peritoneales limitadas y/o citología peritoneal positiva. Se utilizó una técnica HIPEC abierta con 460 mg/m2 de oxaliplatino hipertérmico (30 minutos) seguido de docetaxel normotérmico (90 minutos) en dosis crecientes (0, 50, 75 mg/m2 ). RESULTADOS: Entre 2014 y 2017, se incluyeron 37 pacientes. De los 25 pacientes que completaron la totalidad del protocolo del estudio, 4 pacientes fueron tratados en el nivel de dosis 1 (0 mg/m2 de docetaxel), 6 pacientes en el nivel de dosis 2 (50 mg/m2 ) y 4 pacientes en el nivel de dosis 3 (75 mg/m2 ). En el nivel de dosis 3, se produjeron dos casos de toxicidad limitante de dosis (dose-limiting toxicities, DLTs), ambas asociadas con un íleo postoperatorio. Posteriormente, otros 11 pacientes fueron tratados con el nivel de dosis 2, y no se produjeron más DLTs. La MTD de docetaxel intraperitoneal fue de 50 mg/m2 . Se registraron efectos adversos graves en 17 de 25 pacientes. La tasa de reoperación fue del 16% (n = 4) y la mortalidad relacionada con el tratamiento fue del 8% (n = 2; ambos en el nivel de dosis 3).

Impact of Age and Comorbidity on Choice and Outcome of Two Different Treatment Options for Patients with Potentially Curable Esophageal Cancer.

PURPOSE: This study was designed to assess the impact of age and comorbidity on choice and outcome of definitive chemoradiotherapy (dCRT) or neoadjuvant chemoradiotherapy plus surgery. METHODS: In this population-based study, all patients with potentially curable EC (cT1N+/cT2-3, TX, any cN, cM0) diagnosed in the South East of the Netherlands between 2004 and 2014 were included. Kaplan-Meier method with log-rank tests and multivariable Cox regression analysis were used to compare overall survival (OS). RESULTS: A total of 702 patients was included. Age ≥ 75 years and multiple comorbidities were associated with a higher probability for dCRT (odds ratio [OR] 8.58; 95% confidence interval [CI] 4.72-15.58; and OR 3.09; 95% CI 1.93-4.93). The strongest associations were found for the combination of hypertension plus diabetes (OR 3.80; 95% CI 1.97-7.32) and the combination of cardiovascular with pulmonary comorbidity (OR 3.18; 95% CI 1.57-6.46). Patients with EC who underwent dCRT had a poorer prognosis than those who underwent nCRT plus surgery, irrespective of age, number, and type of comorbidities. In contrast, for patients with squamous cell carcinoma with ≥ 2 comorbidities or age ≥ 75 years, OS was comparable between both groups (hazard ratio [HR] 1.52; 95% CI 0.78-2.97; and HR 0.73; 95% CI 0.13-4.14). CONCLUSIONS: Histological tumor type should be acknowledged in treatment choices for patients with esophageal cancer. Neoadjuvant chemoradiotherapy plus surgery should basically be advised as treatment of choice for operable esophageal adenocarcinoma patients. For patients with esophageal squamous cell carcinoma with ≥ 2 comorbidities or age ≥ 75 years, dCRT may be the preferred strategy.

Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy versus palliative systemic chemotherapy in stomach cancer patients with peritoneal dissemination, the study protocol of a multicentre randomised controlled trial (PERISCOPE II).

BACKGROUND: At present, palliative systemic chemotherapy is the standard treatment in the Netherlands for gastric cancer patients with peritoneal dissemination. In contrast to lymphatic and haematogenous dissemination, peritoneal dissemination may be regarded as locoregional spread of disease. Administering cytotoxic drugs directly into the peritoneal cavity has an advantage over systemic chemotherapy since high concentrations can be delivered directly into the peritoneal cavity with limited systemic toxicity. The combination of a radical gastrectomy with cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) has shown promising results in patients with gastric cancer in Asia. However, the results obtained in Asian patients cannot be extrapolated to Western patients. The aim of this study is to compare the overall survival between patients with gastric cancer with limited peritoneal dissemination and/or tumour positive peritoneal cytology treated with palliative systemic chemotherapy, and those treated with gastrectomy, CRS and HIPEC after neoadjuvant systemic chemotherapy. METHODS: In this multicentre randomised controlled two-armed phase III trial, 106 patients will be randomised (1:1) between palliative systemic chemotherapy only (standard treatment) and gastrectomy, CRS and HIPEC (experimental treatment) after 3-4 cycles of systemic chemotherapy.Patients with gastric cancer are eligible for inclusion if (1) the primary cT3-cT4 gastric tumour including regional lymph nodes is considered to be resectable, (2) limited peritoneal dissemination (Peritoneal Cancer Index < 7) and/or tumour positive peritoneal cytology are confirmed by laparoscopy or laparotomy, and (3) systemic chemotherapy was given (prior to inclusion) without disease progression. DISCUSSION: The PERISCOPE II study will determine whether gastric cancer patients with limited peritoneal dissemination and/or tumour positive peritoneal cytology treated with systemic chemotherapy, gastrectomy, CRS and HIPEC have a survival benefit over patients treated with palliative systemic chemotherapy only. TRIAL REGISTRATION: clinicaltrials.gov NCT03348150 ; registration date November 2017; first enrolment November 2017; expected end date December 2022; trial status: Ongoing.

Impact of upfront randomization for postoperative treatment on quality of surgery in the CRITICS gastric cancer trial.

BACKGROUND: Preoperative randomization for postoperative treatment might affect quality of surgery. In the CRITICS trial (ChemoRadiotherapy after Induction chemotherapy In Cancer of the Stomach), patients were randomized before treatment to receive chemotherapy prior to a D1 + gastrectomy (removal of lymph node station (LNS) 1-9 + 11), followed by either chemotherapy (CT) or chemoradiotherapy (CRT). In this analysis, the influence of upfront randomization on the quality of surgery was evaluated. METHODS: Quality of surgery was analyzed in both study arms using surgicopathological compliance (removal of ≥ 15 lymph nodes), surgical compliance (removal of the indicated LNS), and surgical contamination (removal of LNS that should be left in situ). Furthermore, the 'Maruyama Index of Unresected disease' (MI) was evaluated in both study arms, and validated with overall survival. RESULTS: Between 2007 and 2015, 788 patients with gastric cancer were included in the CRITICS study of which 636 patients were operated with curative intent. No difference was observed between the CT and CRT group regarding surgicopathological compliance (74.8% vs 70.9%, P = 0.324), surgical compliance (43.2% vs 39.2%, P = 0.381), and surgical contamination (59.4% vs 59.9%, P = 0.567). Median MI was 1 in both groups (range CT 0-88 and CRT 0-136, P = 0.700). A MI below 5 was associated with better overall survival (CT: P = 0.009 and CRT: P = 0.013). CONCLUSION: Surgical quality parameters were similar in both study arms in the CRITICS gastric cancer trial, indicating that upfront randomization for postoperative treatment had no impact on the quality of surgery. A Maruyama Index below five was associated with better overall survival.

Using textbook outcome as a measure of quality of care in oesophagogastric cancer surgery.

BACKGROUND: Textbook outcome is a multidimensional measure representing an ideal course after oesophagogastric cancer surgery. It comprises ten perioperative quality-of-care parameters and has been developed recently using population-based data. Its association with long-term outcome is unknown. The objectives of this study were to validate the clinical relevance of textbook outcome at a hospital level, and to assess its relation with long-term survival after treatment for oesophagogastric cancer. METHODS: All patients with oesophageal or gastric cancer scheduled for surgery with curative intent between January 2009 and June 2015 were selected from an institutional database. A Cox model was used to study the association between textbook outcome and survival. RESULTS: A textbook outcome was achieved in 58 of 144 patients (40·3 per cent) with oesophageal cancer and in 48 of 105 (45·7 per cent) with gastric cancer. Factors associated with not achieving a textbook outcome were failure to achieve a lymph node yield of at least 15 (after oesophagectomy) and postoperative complications of grade II or more. After oesophagectomy, median overall survival was longer for patients with a textbook outcome than for patients without (median not reached versus 33 months; P = 0·012). After gastrectomy, median survival was 54 versus 33 months respectively (P = 0·018). In multivariable analysis, textbook outcome was associated with overall survival after oesophagectomy (hazard ratio 2·38, 95 per cent c.i. 1·29 to 4·42) and gastrectomy (hazard ratio 2·58, 1·25 to 5·32). CONCLUSION: Textbook outcome is a clinically relevant measure in patients undergoing oesophagogastric cancer surgery as it can identify underperforming parameters in a hospital setting. Overall survival in patients with a textbook outcome is better than in patients without a textbook outcome.

Outcomes after prophylactic gastrectomy for hereditary diffuse gastric cancer.

BACKGROUND: Patients with hereditary diffuse gastric cancer and a CDH1 mutation have a 60-80 per cent lifetime risk of developing diffuse gastric cancer. Total prophylactic gastrectomy eliminates this risk, but is associated with considerable morbidity. The effectiveness (removal of all gastric mucosa) and outcomes of this procedure were evaluated retrospectively. METHODS: All consecutive individuals undergoing a prophylactic gastrectomy for a CDH1 mutation or gastric signet ring cell foci at the authors' institute between 2005 and 2017 were included. RESULTS: In 25 of 26 patients, intraoperative frozen-section examination (proximal resection margin) was used to verify complete removal of gastric mucosa. All definitive resection margins were free of gastric mucosa, but only after the proximal margin had been reresected in nine patients. In the first year after surgery, five of the 26 patients underwent a relaparotomy for adhesiolysis (2 patients) or jejunostomy-related complications (3 patients). Six patients were readmitted to the hospital within 1 year for nutritional and/or psychosocial support (4 patients) or surgical reintervention (2 patients). Mean weight loss after 1 year was 15 (95 per cent c.i. 12 to 18) per cent. For the 25 patients with a follow-up at 1 year or more, functional complaints were reported more frequently at 1 year than at 3 months after the operation: bile reflux (15 versus 11 patients respectively) and dumping (11 versus 7 patients). The majority of patients who worked or studied before surgery (15 of 19) had returned fully to these activities within 1 year. CONCLUSION: The considerable morbidity and functional consequences of gastrectomy should be considered when counselling individuals with an inherited predisposition to diffuse gastric cancer. Intraoperative frozen-section examination is recommended to remove all risk-bearing gastric mucosa.

Association between hospital volume and quality of gastric cancer surgery in the CRITICS trial.

BACKGROUND: Studies investigating the association between hospital volume and quality of gastric cancer surgery are lacking. In the present study, the effect of hospital volume on quality of gastric cancer surgery was evaluated by analysing data from the CRITICS (ChemoRadiotherapy after Induction chemotherapy In Cancer of the Stomach) trial. METHODS: Patients who underwent gastrectomy with curative intent in the Netherlands were selected from the CRITICS trial database. Annual hospital volume of participating centres was derived from the Netherlands Cancer Registry. Hospital volume was categorized into very low (1-10 gastrectomies per year per institution), low (11-20), medium (21-30) and high (31 or more), and linked to the CRITICS database. Quality of surgery was analysed by surgicopathological compliance (removal of at least 15 lymph nodes), surgical compliance (removal of indicated lymph node stations) and the Maruyama Index. Postoperative morbidity and mortality were also compared between hospital categories. RESULTS: Between 2007 and 2015, 788 patients were included in the CRITICS study, of whom 494 were analysed. Surgicopathological compliance was higher (86·7 versus 50·4 per cent; P < 0·001), surgical compliance was greater (52·9 versus 19·8 per cent; P < 0·001) and median Maruyama Index was lower (0 versus 6; P = 0·006) in high-volume hospitals compared with very low-volume hospitals. There was no statistically significant difference in postoperative complications or mortality between the hospital volume categories. CONCLUSION: Surgery performed in high-volume hospitals was associated with better surgical quality than surgery carried out in lower-volume hospitals.

Preoperative image-guided identification of response to neoadjuvant chemoradiotherapy in esophageal cancer (PRIDE): a multicenter observational study.

BACKGROUND: Nearly one third of patients undergoing neoadjuvant chemoradiotherapy (nCRT) for locally advanced esophageal cancer have a pathologic complete response (pCR) of the primary tumor upon histopathological evaluation of the resection specimen. The primary aim of this study is to develop a model that predicts the probability of pCR to nCRT in esophageal cancer, based on diffusion-weighted magnetic resonance imaging (DW-MRI), dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and 18F-fluorodeoxyglucose positron emission tomography with computed tomography (18F-FDG PET-CT). Accurate response prediction could lead to a patient-tailored approach with omission of surgery in the future in case of predicted pCR or additional neoadjuvant treatment in case of non-pCR. METHODS: The PRIDE study is a prospective, single arm, observational multicenter study designed to develop a multimodal prediction model for histopathological response to nCRT for esophageal cancer. A total of 200 patients with locally advanced esophageal cancer - of which at least 130 patients with adenocarcinoma and at least 61 patients with squamous cell carcinoma - scheduled to receive nCRT followed by esophagectomy will be included. The primary modalities to be incorporated in the prediction model are quantitative parameters derived from MRI and 18F-FDG PET-CT scans, which will be acquired at fixed intervals before, during and after nCRT. Secondary modalities include blood samples for analysis of the presence of circulating tumor DNA (ctDNA) at 3 time-points (before, during and after nCRT), and an endoscopy with (random) bite-on-bite biopsies of the primary tumor site and other suspected lesions in the esophagus as well as an endoscopic ultrasonography (EUS) with fine needle aspiration of suspected lymph nodes after finishing nCRT. The main study endpoint is the performance of the model for pCR prediction. Secondary endpoints include progression-free and overall survival. DISCUSSION: If the multimodal PRIDE concept provides high predictive performance for pCR, the results of this study will play an important role in accurate identification of esophageal cancer patients with a pCR to nCRT. These patients might benefit from a patient-tailored approach with omission of surgery in the future. Vice versa, patients with non-pCR might benefit from additional neoadjuvant treatment, or ineffective therapy could be stopped. TRIAL REGISTRATION: The article reports on a health care intervention on human participants and was prospectively registered on March 22, 2018 under ClinicalTrials.gov Identifier: NCT03474341 .

Evaluation of PET and laparoscopy in STagIng advanced gastric cancer: a multicenter prospective study (PLASTIC-study).

BACKGROUND: Initial staging of gastric cancer consists of computed tomography (CT) and gastroscopy. In locally advanced (cT3-4) gastric cancer, fluorodeoxyglucose positron emission tomography with CT (FDG-PET/CT or PET) and staging laparoscopy (SL) may have a role in staging, but evidence is scarce. The aim of this study is to evaluate the impact and cost-effectiveness of PET and SL in addition to initial staging in patients with locally advanced gastric cancer. METHODS: This prospective observational cohort study will include all patients with a surgically resectable, advanced gastric adenocarcinoma (cT3-4b, N0-3, M0), that are scheduled for treatment with curative intent after initial staging with gastroscopy and CT. The modalities to be investigated in this study is the addition of PET and SL. The primary outcome of this study is the proportion of patients in whom the PET or SL lead to a change in treatment strategy. Secondary outcome parameters are: diagnostic performance, morbidity and mortality, quality of life, and cost-effectiveness of these additional diagnostic modalities. The study recently started in August 2017 with a duration of 36 months. At least 239 patients need to be included in this study to demonstrate that the diagnostic modalities are break-even. Based on the annual number of gastrectomies in the participating centers, it is estimated that approximately 543 patients are included in this study. DISCUSSION: In this study, it is hypothesized that performing PET and SL for locally advanced gastric adenocarcinomas results in a change of treatment strategy in 27% of patients and an annual cost-reduction in the Netherlands of €916.438 in this patient group by reducing futile treatment. The results of this study may be applicable to all countries with comparable treatment algorithms and health care systems. TRIAL REGISTRATION: NCT03208621 . This trial was registered prospectively on June 30, 2017.

Nationwide comprehensive gastro-intestinal cancer cohorts: the 3P initiative.

BACKGROUND: The increasing sub-classification of cancer patients due to more detailed molecular classification of tumors, and limitations of current trial designs, require innovative research designs. We present the design, governance and current standing of three comprehensive nationwide cohorts including pancreatic, esophageal/gastric, and colorectal cancer patients (NCT02070146). Multidisciplinary collection of clinical data, tumor tissue, blood samples, and patient-reported outcome (PRO) measures with a nationwide coverage, provides the infrastructure for future and novel trial designs and facilitates research to improve outcomes of gastrointestinal cancer patients. MATERIAL AND METHODS: All patients aged ≥18 years with pancreatic, esophageal/gastric or colorectal cancer are eligible. Patients provide informed consent for: (1) reuse of clinical data; (2) biobanking of primary tumor tissue; (3) collection of blood samples; (4) to be informed about relevant newly identified genomic aberrations; (5) collection of longitudinal PROs; and (6) to receive information on new interventional studies and possible participation in cohort multiple randomized controlled trials (cmRCT) in the future. RESULTS: In 2015, clinical data of 21,758 newly diagnosed patients were collected in the Netherlands Cancer Registry. Additional clinical data on the surgical procedures were registered in surgical audits for 13,845 patients. Within the first two years, tumor tissue and blood samples were obtained from 1507 patients; during this period, 1180 patients were included in the PRO registry. Response rate for PROs was 90%. The consent rate to receive information on new interventional studies and possible participation in cmRCTs in the future was >85%. The number of hospitals participating in the cohorts is steadily increasing. CONCLUSION: A comprehensive nationwide multidisciplinary gastrointestinal cancer cohort is feasible and surpasses the limitations of classical study designs. With this initiative, novel and innovative studies can be performed in an efficient, safe, and comprehensive setting.

Adjuvant Chemoradiotherapy for Non-Pretreated Gastric Cancer.

BACKGROUND: While the curative approach to gastric cancer includes perioperative regimens in several countries, a substantial proportion of patients may not receive treatment prior to surgery. This study examines the adjuvant provision of chemoradiotherapy (CRT) for non-pretreated patients with cancer of the stomach including the gastric cardia. METHODS: All surgically treated patients with primary adenocarcinoma of the stomach and gastric cardia diagnosed between January 2004-December 2013 were selected from the Netherlands Cancer Registry. Patients who did not receive neoadjuvant treatment were included. Early gastric cancers (cT1), postoperative deaths within 90 days, patients with metastatic disease (M1), patients who received adjuvant chemotherapy and patients with macroscopic tumor after surgery (R2) were excluded. RESULTS: Some 3277 patients underwent surgery, and 99 patients (3%) received adjuvant CRT. Treatment was more often administered in patients with a younger age (<65 years) and a high socioeconomic status (SES), in case of non-cardia cancer, positive lymph nodes, and positive resection margins (R1). Median survival time was 28 months (95% CI 17-39), compared to 35 months (95% CI 33-38) in CRT-naïve patients. After adjustment for confounders, a small net benefit for adjuvant CRT was found (hazard ratio, HR: 0.75, 95% CI 0.58-0.96). In subgroup analyses, benefit was most pronounced for patients with seven or more lymph metastases. CONCLUSIONS: Marginal survival benefit was observed for adjuvant CRT in gastric cancer patients who did not receive neoadjuvant treatment. Treatment could be considered for patients with disease involving nodal invasion and those left with microscopic residual disease after surgery.

Textbook outcome as a composite measure in oesophagogastric cancer surgery.

BACKGROUND: Quality assurance is acknowledged as a crucial factor in the assessment of oncological surgical care. The aim of this study was to develop a composite measure of multiple outcome parameters defined as 'textbook outcome', to assess quality of care for patients undergoing oesophagogastric cancer surgery. METHODS: Patients with oesophagogastric cancer, operated on with the intent of curative resection between 2011 and 2014, were identified from a national database (Dutch Upper Gastrointestinal Cancer Audit). Textbook outcome was defined as the percentage of patients who underwent a complete tumour resection with at least 15 lymph nodes in the resected specimen and an uneventful postoperative course, without hospital readmission. Hospital variation in textbook outcome was analysed after adjustment for case-mix factors. RESULTS: In total, 2748 patients with oesophageal cancer and 1772 with gastric cancer were included in this study. A textbook outcome was achieved in 29·7 per cent of patients with oesophageal cancer and 32·1 per cent of those with gastric cancer. Adjusted textbook outcome rates varied from 8·5 to 52·4 per cent between hospitals. The outcome parameter 'at least 15 lymph nodes examined' had the greatest negative impact on a textbook outcome both for patients with oesophageal cancer and for those with gastric cancer. CONCLUSION: Most patients did not achieve a textbook outcome and there was wide variation between hospitals.

Hospital of diagnosis and probability of having surgical treatment for resectable gastric cancer.

BACKGROUND: Gastric cancer surgery is increasingly being centralized in the Netherlands, whereas the diagnosis is often made in hospitals where gastric cancer surgery is not performed. The aim of this study was to assess whether hospital of diagnosis affects the probability of undergoing surgery and its impact on overall survival. METHODS: All patients with potentially curable gastric cancer according to stage (cT1/1b-4a, cN0-2, cM0) diagnosed between 2005 and 2013 were selected from The Netherlands Cancer Registry. Multilevel logistic regression was used to examine the probability of undergoing surgery according to hospital of diagnosis. The effect of variation in probability of undergoing surgery among hospitals of diagnosis on overall survival during the intervals 2005-2009 and 2010-2013 was examined by using Cox regression analysis. RESULTS: A total of 5620 patients with potentially curable gastric cancer, diagnosed in 91 hospitals, were included. The proportion of patients who underwent surgery ranged from 53.1 to 83.9 per cent according to hospital of diagnosis (P < 0.001); after multivariable adjustment for patient and tumour characteristics it ranged from 57.0 to 78.2 per cent (P < 0.001). Multivariable Cox regression showed that patients diagnosed between 2010 and 2013 in hospitals with a low probability of patients undergoing curative treatment had worse overall survival (hazard ratio 1.21; P < 0.001). CONCLUSION: The large variation in probability of receiving surgery for gastric cancer between hospitals of diagnosis and its impact on overall survival indicates that gastric cancer decision-making is suboptimal.

Role of omentectomy as part of radical surgery for gastric cancer.

BACKGROUND: A complete omentectomy is recommended as part of radical (sub)total gastrectomy for gastric cancer, but there is little evidence to suggest any survival benefit. The aim of this study was to evaluate the incidence of, and risk factors for, metastases in the greater omentum in patients undergoing gastrectomy for gastric cancer. METHODS: This was a multicentre prospective cohort study (OMEGA trial) of consecutive patients with gastric cancer undergoing (sub)total gastrectomy with complete en bloc omentectomy and modified D2 lymphadenectomy. After resection, the omentum was separated from the gastrectomy specimen distal to the gastroepiploic vessels and sent separately for pathological examination. The primary endpoint was the presence of metastases in the greater omentum. RESULTS: Of 100 included patients, five (5·0 per cent) had metastases in the greater omentum. Pathology results showed advanced tumours in all five (pT4b N1 M1, pT4b N2 M1, ypT4a N1 M1, ypT3 N2 M0, ypT3 N3 M0). The resection was microscopically non-radical at the proximal (3) or distal (2) resection margin in all of these patients. Metastases in the greater omentum correlated significantly with a microscopically non-radical resection, tumour expansion in the oesophagus or duodenum, linitis plastica or a proximal gastric tumour with diameter of at least 5 cm, stage III-IV disease and (y)pM1 category. CONCLUSION: In resectable gastric cancer, the incidence of metastases in the greater omentum is low, and when present associated with advanced disease and non-radical features. Thus, omentectomy as part of a radical gastrectomy may be omitted. REGISTRATION NUMBER: NCT02050659 ( http://www.clinicaltrials.gov).

Early outcomes from the Dutch Upper Gastrointestinal Cancer Audit.

BACKGROUND: In 2011, the Dutch Upper Gastrointestinal Cancer Audit (DUCA) group began nationwide registration of all patients undergoing surgery with the intention of resection for oesophageal or gastric cancer. The aim of this study was to describe the initiation and implementation of this process along with an overview of the results. METHODS: The DUCA is part of the Dutch Institute for Clinical Auditing. The audit provides (surgical) teams with reliable, weekly updated, benchmarked information on process and (case mix-adjusted) outcome measures. To accomplish this, a web-based registration was designed, based on a set of predefined quality measures. RESULTS: Between 2011 and 2014, a total of 2786 patients with oesophageal cancer and 1887 with gastric cancer were registered. Case ascertainment approached 100 per cent for patients registered in 2013. The percentage of patients with oesophageal cancer starting treatment within 5 weeks of diagnosis increased significantly over time from 32·5 per cent in 2011 to 41·0 per cent in 2014 (P < 0·001). The percentage of patients with a minimum of 15 examined lymph nodes in the resected specimen also increased significantly for both oesophageal cancer (from 50·3 per cent in 2011 to 73·0 per cent in 2014; P < 0·001) and gastric cancer (from 47·5 per cent in 2011 to 73·6 per cent in 2014; P < 0·001). Postoperative mortality remained stable (around 4·0 per cent) for patients with oesophageal cancer, and decreased for patients with gastric cancer (from 8·0 per cent in 2011 to 4·0 per cent in 2014; P = 0·031). CONCLUSION: Nationwide implementation of the DUCA has been successful. The results indicate a positive trend for various process and outcome measures.

Biobanking of fresh-frozen endoscopic biopsy specimens from esophageal adenocarcinoma.

The process of preparing endoscopic esophageal adenocarcinoma samples for next-generation DNA/RNA sequencing is poorly described. Therefore, we assessed the feasibility and pitfalls of preparing esophageal adenocarcinoma endoscopic biopsies toward DNA/RNA samples suitable for next-generation sequencing. In this prospective study, four tumor biopsy samples were collected from consecutive esophageal cancer patients during esophagogastroduodenoscopy and fresh-frozen in liquid nitrogen. DNA and RNA were isolated from samples with a tumor percentage of at least 50%. For next-generation sequencing, double-stranded DNA (dsDNA) is required and high-quality RNA preferred. The quantity dsDNA and RNA quantity and quality were assessed with the Nanodrop 2000 spectrophotometer (Thermo Fisher Scientific, Waltham, MA, USA) and Agilent 2100 Bioanalyzer (Agilent, Santa Clara, CA, USA). Biopsy samples of 69 consecutive patients with esophageal adenocarcinoma were included. In five patients (7%), the tumor percentage was less than 50% in all four biopsies. Using a protocol allowing simultaneous DNA and RNA isolation, the median dsDNA yield was 2.4 µg (range 0.1-12.0 µg) and the median RNA yield was 0.5 µg (range 0.01-2.05 µg). The median RNA integrity number of samples that were fresh-frozen within 30 minutes after sampling was 6.7 (range 4.2-8.9) compared with 2.5 (1.8-4.5) for samples that were fresh-frozen after 2 hours. The results from this study show that obtaining dsDNA and RNA for next-generation sequencing from endoscopic esophageal adenocarcinoma samples is feasible. Tumor percentage and dsDNA/RNA yield and quality emphasize the need for sampling multiple biopsies and minimizing the delay before fresh-freezing.

External validation of a lung cancer-based prediction model for two-year mortality in esophageal cancer patient cohorts.

PURPOSE/OBJECTIVE: Chemo-radiotherapy can improve the oncological outcome of esophageal cancer (EC) patients, but may cause long term radiation-induced toxicity, including an increased risk of non-cancer related death. For lung cancer patients, a model to predict 2-year total mortality using mean heart dose (MHD) and gross tumor volume (GTV) has previously been developed and validated. This project aimed to externally validate this model in EC patients. METHODS: Five EC patient cohorts from 3 different Dutch centres were used for model validation. External validity of the model was assessed separately in definitive (n = 170) and neo-adjuvant (n = 568) chemoradiotherapy (dCRT and nCRT) patients. External validity was assessed in terms of calibration by calibration plots, calibration-in-the-large (CITL) and calibration slope (CS), and discrimination by assessment of the c-statistic. If suboptimal model performance was observed, the model was further updated accordingly. RESULTS: For the dCRT patients, good calibration was found after adjustment of the intercept (CITL 0.00; CS 1.08). The c-statistic of the adjusted model was 0.67 (95%CI: 0.58 to 0.75). For nCRT patients the model needed adjustment of both the slope and the intercept because of initial miscalibration in the validation population (CITL 0.00; CS 1.72). After recalibration, the model showed perfect calibration (i.e., CITL 0, CS 1), as is common after recalibration. The c-statistic of the recalibrated model equaled 0.62 (95%CI: 0.57 to 0.67). CONCLUSION: The existing model for 2-year mortality prediction in lung cancer patients, based on the predictive factors MHD and GTV, showed good performance in EC patients after updating the intercept and/or slope of the original model.