Gender differences in tumor characteristics, treatment allocation and survival in stage I-III pancreatic cancer: a nationwide study.

INTRODUCTION: Sex and gender are modulators of health and disease and may have impact on treatment allocation and survival in patients with cancer. In this study, we analyzed the impact of sex and gender on treatment allocation and overall survival in patients with stage I-III pancreatic cancer. METHODS: Patients with stage I-III pancreatic cancer diagnosed between 2015 and 2020 were selected from the nationwide Netherlands Cancer Registry. Associations between sex and gender and the probability of receiving surgical and/or systemic treatment were examined with multivariable logistic regression analyses. Overall survival was assessed with log rank test and multivariable Cox proportional hazard analysis. RESULTS: Among 6855 patients, 51.2 % were female. Multivariable logistic regression analyses with adjustment for known confounders (age, performance status, comorbidities, tumor location, tumor stage and previous malignancies) showed that females less often received systemic chemotherapy compared to males (OR 0.799, 95 %CI 0.703-0.909, p < .001). No difference was found in the probability for undergoing surgical resection. Furthermore, females had worse overall survival compared to males (median OS 8.5 and 9.2 months respectively, 95 %CI 8.669-9.731). CONCLUSION: This nationwide study found that female patients with stage I-III pancreatic cancer significantly less often received systemic treatment and had worse overall survival as compared to males. Disparities in pancreatic cancer care can be decreased by recognizing and resolving potential obstacles or biases in treatment decision-making.

Survival after Ivor Lewis versus McKeown esophagectomy for cancer: propensity score matched analysis.

It is unknown whether Ivor Lewis (IL) or McKeown (McK) esophagectomy is preferred in patients with potentially curable esophageal or gastro-esophageal junction (GEJ) cancer. Patients with mid- and distal esophageal and GEJ cancer without distant metastases who underwent IL or McK esophagectomy in the Netherlands between 2015 and 2017, were selected from the Netherlands Cancer Registry. Patients were propensity score matched for sex, age, American Society of Anesthesiologist classification, comorbidity, tumor type, tumor location, clinical stage, neoadjuvant treatment and year of diagnosis. The primary outcome was a 3-year relative survival (RS). Secondary outcome parameters were number of lymph nodes examined, number of positive lymph nodes, radical resection rate, tumor regression grade, post-operative complications and mortality. A total of 1627 patients who underwent IL (n = 1094) or McK (n = 533) esophagectomy were included. Patient and tumor characteristics were balanced after propensity score matching, leaving 658 patients to be compared. The 3-year RS was 54% after IL and 50% after McK esophagectomy, P = 0.140. The median number of lymph nodes examined, median number of positive lymph nodes, radical resection rate and tumor regression grade were comparable between both groups. Recurrent laryngeal nerve palsy (2 vs. 5%, P = 0.006) occurred less frequently after IL esophagectomy. No differences were observed in post-operative anastomotic leakage rate, pulmonary complication rate and mortality rates. There was no statistically significant difference in the 3-year RS between IL and McK esophagectomy. Based on these results, both IL and McK esophagectomy can be performed in patients with mid to distal esophageal and GEJ cancer.

Team dynamics and clinician's experience influence decision-making during Upper-GI multidisciplinary team meetings: A multiple case study.

Background: The probability of undergoing treatment with curative intent for esophagogastric cancer has been shown to vary considerately between hospitals of diagnosis. Little is known about the factors that attribute to this variation. Since clinical decision making (CDM) partially takes place during an MDTM, the aim of this qualitative study was to assess clinician's perspectives regarding facilitators and barriers associated with CDM during MDTM, and second, to identify factors associated with CDM during an MDTM that may potentially explain differences in hospital practice. Methods: A multiple case study design was conducted. The thematic content analysis of this qualitative study, focused on 16 MDTM observations, 30 semi-structured interviews with clinicians and seven focus groups with clinicians to complement the collected data. Interviews were transcribed ad verbatim and coded. Results: Factors regarding team dynamics that were raised as aspects attributing to CDM were clinician's personal characteristics such as ambition and the intention to be innovative. Clinician's convictions regarding a certain treatment and its outcomes and previous experiences with treatment outcomes, and team dynamics within the MDTM influenced CDM. In addition, a continuum was illustrated. At one end of the continuum, teams tended to be more conservative, following the guidelines more strictly, versus the opposite in which hospitals tended towards a more invasive approach maximizing the probability of curation. Conclusion: This study contributes to the awareness that variation in team dynamics influences CDM during an MDTM.

Clinical variation in the organization of clinical pathways in esophagogastric cancer, a mixed method multiple case study.

BACKGROUND: Among esophagogastric cancer patients, the probability of having undergone treatment with curative intent has been shown to vary, depending on the hospital of diagnosis. However, little is known about the factors that contribute to this variation. In this study, we sought to understand the organization of clinical pathways and their association with variation in practice. METHODS: A mixed-method study using quantitative and qualitative data was conducted. Quantitative data were obtained from the Netherlands Cancer Registry (e.g., outpatient clinic consultations and diagnostic procedures). For qualitative data, thematic content analysis was performed using semi-structured interviews (n = 30), observations of outpatient clinic consultations (n = 26), and multidisciplinary team meetings (MDTM, n = 16) in eight hospitals, to assess clinicians' perspectives regarding the clinical pathways. RESULTS: Quantitative analyses showed that patients more often underwent surgical consultation prior to the MDTM in hospitals associated with a high probability of receiving treatment with curative intent, but more often consulted with a geriatrician in hospitals associated with a low probability of such treatment. The organization of clinical pathways was analyzed quantitatively at three levels: regional, local, and patient levels. At a regional level, hospitals differed in terms of the number of patients discussed during the MDTM. At the local level, the revision of radiological images and restaging after neoadjuvant treatment varied. At the patient level, some hospitals routinely conduct fitness tests, whereas others estimated the patient's physical fitness during an outpatient clinic consultation. Few clinicians performed a standard geriatric consultation in older patients to assess their mental fitness and frailty. CONCLUSION: Surgical consultation prior to MDTM was more often conducted in hospitals associated with a high probability of receiving treatment with curative intent, whereas a geriatrician was consulted more often in hospitals associated with a low probability of receiving such treatment.

Occult lymph node metastases in patients without residual muscle-invasive bladder cancer at radical cystectomy with or without neoadjuvant chemotherapy: a nationwide study of 5417 patients.

PURPOSE: Little is known about the prevalence of occult lymph node metastases (LNM) in muscle-invasive bladder cancer (MIBC) patients with pathological downstaging of the primary tumor. We aimed to estimate the prevalence of occult LNM in patients without residual MIBC at radical cystectomy (RC) with or without neoadjuvant chemotherapy (NAC) or neoadjuvant radiotherapy (NAR), and to assess overall survival (OS). METHODS: Patients with cT2-T4aN0M0 urothelial MIBC who underwent RC plus pelvic lymph node dissection (PLND) with curative intent between January 1995-December 2013 (retrospective Netherlands Cancer Registry (NCR) cohort) and November 2017-October 2019 (prospective NCR-BlaZIB cohort (acronym in Dutch: BlaaskankerZorg In Beeld; in English: Insight into bladder cancer care)) were identified from the nationwide NCR. The prevalence of occult LNM was calculated and OS of patients with <(y)pT2N0 vs. <(y)pT2N+ disease was estimated by the Kaplan-Meier method. RESULTS: In total, 4657 patients from the NCR cohort and 760 patients from the NCR-BlaZIB cohort were included. Of 1374 patients downstaged to <(y)pT2, 4.3% (N = 59) had occult LNM 4.1% (N = 49) of patients with cT2-disease and 5.6% (N = 10) with cT3-4a-disease. This was 4.0% (N = 44) in patients without NAC or NAR, 4.5% (N = 10) in patients with NAC, and 13.5% (N = 5) in patients with NAR but number of patients treated with NAR and downstaged disease was small. The prevalence of <(y)pT2N+ disease was 4.2% (N = 48) in the NCR cohort and 4.6% (N = 11) in the NCR-BlaZIB cohort. For patients with <(y)pT2N+ and <(y)pT2N0, median OS was 3.5 years (95% CI 2.5-8.9) versus 12.9 years (95% CI 11.7-14.0), respectively. CONCLUSION: Occult LNM were found in 4.3% of patients with cT2-4aN0M0 MIBC with (near-) complete downstaging of the primary tumor following RC plus PLND. This was regardless of NAC or clinical T-stage. Patients with occult LNM showed considerable worse survival. These results can help in counseling patients for bladder-sparing treatments.

Predictors of undergoing multivisceral resection, margin status and survival in Dutch patients with locally advanced colorectal cancer.

BACKGROUND: The aim of this nationwide observational study was to evaluate factors associated with multivisceral resection (MVR), margin status and overall survival in locally advanced colorectal cancer (CRC). MATERIAL AND METHODS: Patients with (y)pT4, cM0 CRC between 2006 and 2017 were selected from the Netherlands Cancer Registry. Cox-proportional hazards modelling was used for survival analysis, stratified for T4a and T4b. Annual hospital volume cut-off was 75 for colon and 40 for rectal resections. RESULTS: A total of 11.930 patients were included and 2410 patients (20.2%) underwent MVR. Factors associated with MVR for colon and rectal cancer besides cT4 category were more recent diagnosis (OR 3.61, CI 95% 3.06-4.25 (colon) and OR 2.72, CI 95% 1.82-4.08 (rectum)) and high hospital volume (OR 1.20, CI 95% 1.05-1.38 (colon) and OR 2.17, CI 95% 1.55-3.04 (rectum)). Patients ≥70 year were less likely to undergo MVR for colon cancer (OR 0.80, 95% CI 0.70-0.90). Risk factors for incomplete resection were cT4 (OR 3.08, CI 95% 2.35-4.04 (colon) and OR 1.82, CI 95% 1.13-2.94 (rectum)) and poor/undifferentiated tumors (OR 1.41, CI 95% 1.14-1.72 (colon) and OR 1.69, CI 95% 1.05-2.74 (rectum)). More recent diagnosis was independently associated with less incomplete resections in colon cancer (OR 0.58, CI 95% 0.40-0.76). Independent predictors of survival were age, resection margin, nodal status and adjuvant chemotherapy, but not MVR. CONCLUSION: Treatment of locally advanced CRC with MVR at population level was influenced by year of diagnosis and hospital volume. Margin status in colon cancer improved substantially over time.

Prognostic value of patient-reported quality of life for survival in oesophagogastric cancer: analysis from the population-based POCOP study.

BACKGROUND: Accumulating evidence of trials demonstrates that patient-reported health-related quality of life (HRQoL) at diagnosis is prognostic for overall survival (OS) in oesophagogastric cancer. However, real-world data are lacking. Moreover, differences in disease stages and tumour-specific symptoms are usually not taken into consideration. The aim of this population-based study was to assess the prognostic value of HRQoL, including tumour-specific scales, on OS in patients with potentially curable and advanced oesophagogastric cancer. METHODS: Data were derived from the Netherlands Cancer Registry and the patient reported outcome registry (POCOP). Patients included in POCOP between 2016 and 2018 were stratified for potentially curable (cT1-4aNallM0) or advanced (cT4b or cM1) disease. HRQoL was measured with the EORTC QLQ-C30 and the tumour-specific OG25 module. Cox proportional hazards models assessed the impact of HRQoL, sociodemographic and clinical factors (including treatment) on OS. RESULTS: In total, 924 patients were included. Median OS was 38.9 months in potentially curable patients (n = 795) and 10.6 months in patients with advanced disease (n = 129). Global Health Status was independently associated with OS in potentially curable patients (HR 0.89, 99%CI 0.82-0.97), together with several other HRQoL items: appetite loss, dysphagia, eating restrictions, odynophagia, and body image. In advanced disease, the Summary Score was the strongest independent prognostic factor (HR 0.75, 99%CI 0.59-0.94), followed by fatigue, pain, insomnia and role functioning. CONCLUSION: In a real-world setting, HRQoL was prognostic for OS in patients with potentially curable and advanced oesophagogastric cancer. Several HRQoL domains, including the Summary Score and several OG25 items, could be used to develop or update prognostic models.

Hospital variation in sphincter-preservation rates in rectal cancer treatment: results of a population-based study in the Netherlands.

BACKGROUND: This study aimed to examine the sphincter-preservation rate variations in rectal cancer surgery. The influence of hospital volume on sphincter-preservation rates and short-term outcomes (anastomotic leakage (AL), positive circumferential resection margin (CRM), 30- and 90-day mortality rates) were also analysed. METHODS: Non-metastasized rectal cancer patients treated between 2009 and 2016 were selected from the Netherlands Cancer Registry. Surgical procedures were divided into sphincter-preserving surgery and an end colostomy group. Multivariable logistic regression models were generated to estimate the probability of undergoing sphincter-preserving surgery according to the hospital of surgery and tumour height (low, 5 cm or less, mid, more than 5 cm to 10 cm, and high, more than 10 cm). The influence of annual hospital volume (less than 20, 20-39, more than 40 resections) on sphincter-preservation rate and short-term outcomes was also examined. RESULTS: A total of 20 959 patients were included (11 611 sphincter preservation and 8079 end colostomy) and the observed median sphincter-preservation rate in low, mid and high rectal cancer was 29.3, 75.6 and 87.9 per cent respectively. After case-mix adjustment, hospital of surgery was a significant factor for patients' likelihood for sphincter preservation in all three subgroups (P < 0.001). In mid rectal cancer, borderline higher rates of sphincter preservation were associated with low-volume hospitals (odds ratio 1.20, 95 per cent c.i. 1.01 to 1.43). No significant association between annual hospital volume and sphincter-preservation rate in low and high rectal cancer nor short-term outcomes (AL, positive CRM rate and 30- and 90-day mortality rates) was identified. CONCLUSION: This population-based study showed a significant hospital variation in sphincter-preservation rates in rectal surgery. The annual hospital volume, however, was not associated with sphincter-preservation rates in low, and high rectal cancer nor with other short-term outcomes.

Transanal total mesorectal excision and low anterior resection syndrome.

BACKGROUND: Bowel dysfunction after rectal cancer surgery is common, with some experiencing low anterior resection syndrome (LARS) is common after rectal cancer surgery. This study examined if transanal total mesorectal excision (TaTME) has a similar risk of LARS and altered quality of life (QoL) as patients who undergo low anterior resection (LAR). METHODS: Patients who underwent TaTME or traditionally approached total mesorectal excision in a prospective colorectal cancer cohort study (2014-2019) were propensity score matched in a 1 : 1 ratio. LARS and QoL scores were assessed before and after surgery with a primary endpoint of major LARS at 12 months analysed for possible association between factors by logistic regression. RESULTS: Of 61 TaTME and 317 LAR patients eligible, 55 from each group were propensity score matched. Higher LARS scores (30.6 versus 25.4, P = 0.010) and more major LARS (65 versus 42 per cent, P = 0.013; OR 2.64, 95 per cent c.i. 1.22 to 5.71) were reported after TaTME. Additionally, QoL score differences (body image, bowel frequency, and embarrassment) were worse in the TaTME group. CONCLUSIONS: TaTME may be associated with more severe bowel dysfunction than traditional approaches to rectal cancer.

Neoadjuvant Chemoradiotherapy Combined with Atezolizumab for Resectable Esophageal Adenocarcinoma: A Single-arm Phase II Feasibility Trial (PERFECT).

PURPOSE: The CROSS trial established neoadjuvant chemoradiotherapy (nCRT) for patients with resectable esophageal adenocarcinoma (rEAC). In the PERFECT trial, we investigated the feasibility and efficacy of nCRT combined with programmed-death ligand-1 (PD-L1) inhibition for rEAC. PATIENTS AND METHODS: Patients with rEAC received nCRT according to the CROSS regimen combined with five cycles of atezolizumab (1,200 mg). The primary endpoint was the feasibility of administering five cycles of atezolizumab in ≥75% patients. A propensity score-matched nCRT cohort was used to compare pathologic response, overall survival, and progression-free survival. Exploratory biomarker analysis was performed on repeated tumor biopsies. RESULTS: We enrolled 40 patients of whom 85% received all cycles of atezolizumab. Immune-related adverse events of any grade were observed in 6 patients. In total, 83% proceeded to surgery. Reasons for not undergoing surgery were progression (n = 4), patient choice (n = 2), and death (n = 1). The pathologic complete response rate was 25% (10/40). No statistically significant difference in response or survival was found between the PERFECT and the nCRT cohort. Baseline expression of an established IFNγ signature was higher in responders compared with nonresponders (P = 0.043). On-treatment nonresponders showed either a high number of cytotoxic lymphocytes (CTL) with a transcriptional signature consistent with expression of immune checkpoints, or a low number of CTLs. CONCLUSIONS: Combining nCRT with atezolizumab is feasible in patients with rEAC. On the basis of our exploratory biomarker study, future studies are necessary to elucidate the potential of neoadjuvant immunotherapy in patient subgroups.See related commentary by Catenacci, p. 3269.

Extensive diagnostic work-up for patients with carcinoma of unknown primary.

Patients with carcinoma of unknown primary (CUP) present with metastatic disease without an identified primary tumour. The unknown site of origin makes the diagnostic work-up and treatment challenging. Since little information is available regarding diagnostic work-up and treatment in daily practice, we collected and analysed these in a patient cohort with regard to the recommendations of the national CUP guideline. Data of 161 patients diagnosed with CUP in 2014 or 2015 were extracted from the Netherlands Cancer Registry (NCR) and supplemented with diagnostic work-up information from patient files and analysed. Patients underwent an average of five imaging studies during the diagnostic phase (range 1-17). From the tests as recommended in the national guideline on CUP, a chest X-ray was most commonly performed (73%), whereas a PET-CT was done in one out of four patients (24%). Biopsies were taken in 86% of the study population, with Cytokeratin 7 being the most frequently tested histopathological marker (73%). Less than half of patients received therapy (42%). CUP patients undergo extensive diagnostic work-up. The performance status did not influence the extent of the diagnostic work-up in CUP patients, but it was an important factor for receiving treatment.

The metastatic pattern of intestinal and diffuse type gastric carcinoma - A Dutch national cohort study.

INTRODUCTION: The Lauren classification of gastric adenocarcinoma describes three histological subtypes, the intestinal, the diffuse and the mixed type carcinoma. The metastatic pattern of gastric adenocarcinoma by histological subtype has not been studied. METHODS: Gastric adenocarcinoma patients with metastatic disease at the time of diagnosis between 1999 and 2017 were identified through the Netherlands Cancer Registry. The Lauren classification was determined based on pathology reports archived in the Dutch Pathology Registry and was linked to individual cases in the Netherlands Cancer Registry. RESULTS: Among 8 231 newly diagnosed, metastatic and evaluable gastric adenocarcinoma patients, 57 % had an intestinal type carcinoma, 38 % patients had a diffuse type carcinoma and 5 % had a mixed type carcinoma. Intestinal type carcinomas more often metastasized to the liver (57 % versus 21 %, p < 0.0001) and lungs (13 % versus 7 %, p < 0.0001), whereas diffuse type carcinomas more often metastasized to the peritoneum (58 % versus 29 %, p < 0.0001) and bones (9 % versus 6 %, p < 0.0001). Patients with a diffuse type carcinoma had a worse survival perspective regardless of the number or the location of the metastases. CONCLUSION: In this national cohort study, metastatic gastric adenocarcinoma of the intestinal type had a predilection for the liver and that of the diffuse type for the peritoneum.

External Validation of the Dutch SOURCE Survival Prediction Model in Belgian Metastatic Oesophageal and Gastric Cancer Patients.

The SOURCE prediction model predicts individualised survival conditional on various treatments for patients with metastatic oesophageal or gastric cancer. The aim of this study was to validate SOURCE in an external cohort from the Belgian Cancer Registry. Data of Belgian patients diagnosed with metastatic disease between 2004 and 2014 were extracted (n = 4097). Model calibration and discrimination (c-indices) were determined. A total of 2514 patients with oesophageal cancer and 1583 patients with gastric cancer with a median survival of 7.7 and 5.4 months, respectively, were included. The oesophageal cancer model showed poor calibration (intercept: 0.30, slope: 0.42) with an absolute mean prediction error of 14.6%. The mean difference between predicted and observed survival was -2.6%. The concordance index (c-index) of the oesophageal model was 0.64. The gastric cancer model showed good calibration (intercept: 0.02, slope: 0.91) with an absolute mean prediction error of 2.5%. The mean difference between predicted and observed survival was 2.0%. The c-index of the gastric cancer model was 0.66. The SOURCE gastric cancer model was well calibrated and had a similar performance in the Belgian cohort compared with the Dutch internal validation. However, the oesophageal cancer model had not. Our findings underscore the importance of evaluating the performance of prediction models in other populations.

Hospital variance in neoadjuvant rectal cancer treatment and the influence of a national guideline update: Results of a nationwide population-based study.

INTRODUCTION: The aim of this study was to examine the hospital variation in neoadjuvant treatment of rectal cancer according to the different risk groups (low-, intermediate- and high-risk) and evaluate the influence on survival. MATERIALS AND METHODS: Patients with non-metastasized rectal cancer diagnosed between 2009 and 2016 were selected from the Netherlands Cancer Registry. The observed and case-mix adjusted distribution of the different neoadjuvant treatment schemes (none, radiotherapy (RT), chemoradiotherapy (CRT)) by hospital of diagnosis were generated for each risk group in the cohorts before and after the national guideline update of 2014. RESULTS: A total of 25,306 patients were included and after case-mix adjustment, hospital of diagnosis was found to have a significant impact on neoadjuvant treatment administration in each of the three risk groups (p < 0.001). Overall survival was however not influenced, except for the high-risk group where hospitals with highest rates of CRT were associated with a better 5-years overall survival (HR 0.79; p = 0.03). After guideline revision, the rate of patients in the low-risk group who did not undergo RT increased from a median of 30.8% to 90.5% (p < 0.001). CONCLUSION: Although a significant change in treatment was observed after revision of the national guidelines, a wide range of hospital variation still exists in administered neoadjuvant treatment in rectal cancer patients. High-risk rectal cancer patients had a better survival when treated in hospitals with the highest rates of CRT provided. In order to minimize treatment differences, further research into the causes of this variation and implementation of regionalized MDTs may be warranted.

Analysis of 105.000 patients with cancer: have they been discussed in oncologic multidisciplinary team meetings? A nationwide population-based study in the Netherlands.

INTRODUCTION: For optimal oncological care, it is recommended to discuss every patient with cancer in a multidisciplinary team meeting (MDTM). This is a time consuming and expensive practice, leading to a growing demand to change the current workflow. We aimed to investigate the number of patients discussed in MDTMs and to identify characteristics associated with not being discussed. METHODS: Data of patients with a newly diagnosed solid malignant tumour in 2015 and 2016 were analysed through the nationwide population-based Netherlands Cancer Registry (NCR). We clustered tumour types in groups that were frequently discussed within a tumour-specific MDTM. Tumour types without information about MDTMs in the NCR were excluded. Multivariable logistic regression analyses were used to analyse factors associated with not being discussed. RESULTS: Out of 105.305 patients with cancer, 91% were discussed in a MDTM, varying from 74% to 99% between the different tumour groups. Significantly less frequently discussed were patients aged ≥75 years (odds ratio [OR] = 0.7, 95% confidence interval [CI] = 0.6-0.7), patients diagnosed with disease stage I (OR = 0.5, 95% CI = 0.5-0.6), IV (OR = 0.4, 95% CI = 0.4-0.4) or unknown (OR = 0.2, 95% CI = 0.2-0.2) and patients who received no treatment (OR = 0.3, 95% CI = 0.3-0.3). Patients who received a multidisciplinary treatment were more likely to be discussed in contrary to a monodisciplinary treatment (OR = 4.6, 95% CI = 4.2-5.1). CONCLUSION: In general, most patients with cancer were actually discussed in a MDTM, although differences were observed between tumour groups. Factors associated with not being discussed may, at least partially, reflect the absence of a multidisciplinary question. These results form a starting point for debate on a more durable and efficient new MDTM strategy.

Recurrence after preoperative chemotherapy and surgery for gastric adenocarcinoma: a multicenter study.

BACKGROUND: In most western European countries perioperative chemotherapy is a part of standard curative treatment for gastric cancer. Nevertheless, recurrence rates remain high after multimodality treatment. This study examines patterns of recurrence in patients receiving perioperative chemotherapy with surgery for gastric cancer in a real-world setting. METHODS: All patients diagnosed with gastric adenocarcinoma between 2010 and 2015 who underwent at least preoperative chemotherapy and a gastrectomy with curative intent (cT1N+/cT2-4a,X; any cN; cM0) in 18 Dutch hospitals were selected from the Netherlands Cancer Registry. Additional data on chemotherapy and recurrence were collected from medical records. Rates, patterns, and timing of recurrence were examined. Multivariable Cox proportional hazard analyses were used to determine prognostic factors for recurrence. RESULTS: 408 patients were identified. After a median follow-up of 27.8 months, 36.8% of the gastric cancer patients had a recurrence of which the majority (88.8%) had distant metastasis. The 1-year recurrence-free survival was 71.8%. The risk of recurrence was higher in patients with an ypN+ stage (HR 4.92, 95% CI 3.35-7.24), partial or no tumor regression (HR 2.63, 95% CI 1.22-5.64), 3 instead of ≥ 6 chemotherapy cycles (HR 3.04, 95% CI 1.99-4.63), R1 resection (HR 1.52, 95% CI 1.02-2.26), and < 15 resected lymph nodes (HR 1.64, 95% CI 1.14-2.37). CONCLUSION: A considerable amount of gastric cancer patients who were treated with curative intent developed a recurrence despite surgery and perioperative treatment. The majority developed distant metastases, therefore, multimodality treatment approaches should be focused on the prevention of distant rather than locoregional recurrences to improve survival.

International comparison of treatment strategy and survival in metastatic gastric cancer.

Background: In the randomized Asian REGATTA trial, no survival benefit was shown for additional gastrectomy over chemotherapy alone in patients with advanced gastric cancer with a single incurable factor, thereby discouraging surgery for these patients. The purpose of this study was to evaluate treatment strategies for patients with metastatic gastric cancer in daily practice in five European countries, along with relative survival in each country. Methods: Nationwide population-based data from Belgium, Denmark, the Netherlands, Norway and Sweden were combined. Patients with primary metastatic gastric cancer diagnosed between 2006 and 2014 were included. The proportion of gastric resections performed and the administration of chemotherapy (irrespective of surgery) within each country were determined. Relative survival according to country was calculated. Results: Overall, 15 057 patients with gastric cancer were included. The proportion of gastric resections varied from 8·1 per cent in the Netherlands and Denmark to 18·3 per cent in Belgium. Administration of chemotherapy was 39·2 per cent in the Netherlands, compared with 63·2 per cent in Belgium. The 6-month relative survival rate was between 39·0 (95 per cent c.i. 37·8 to 40·2) per cent in the Netherlands and 54·1 (52·1 to 56·9) per cent in Belgium. Conclusion: There is variation in the use of gastrectomy and chemotherapy in patients with metastatic gastric cancer, and subsequent differences in survival.