M.W.J.M. Wouters

Meta-analysis of internal herniation after gastric bypass surgery.

The aim of this study was to provide a systematic and quantitative summary of the association between laparoscopic Roux‐en‐Y gastric bypass (LRYGB) and the reported incidence of internal herniation (IH). The route of the Roux limb and closure of mesenteric and/or mesocolonic defects are described as factors of influence.

Enhancing the quality of care for patients with breast cancer: Seven years of experience with a Dutch auditing system

BACKGROUND Hospitals in the Midwestern part of the Netherlands carried out a clinical audit to monitor the quality of breast cancer care during the years 2002-2008. Compliance with the National Guideline was investigated together with improvement in quality over time. METHODS Patients with a malignancy of the breast (including ductal carcinoma in situ) participated in this study. Nine quality indicators were evaluated over the years. In 2004 and 2005 the hospitals also carried out an intervention project aimed at improvement of the efficiency of both the diagnostic process and the surgical treatment. RESULTS At the end of the project all nine indicators showed significant improvement compared to the start of the project. Discussion of treatment strategy in a multidisciplinary breast cancer team took place more often before surgery (83% versus 56%) as well as after surgery (98% versus 70%). The National Guideline for maximum waiting times was met more often for the outpatient clinic (74% versus 61%), time to diagnosis (92% versus 82%), and surgical treatment (52% versus 34%). More sentinel node procedures were performed successfully (92% versus 69%), and for more patients more than 10 lymph nodes were evaluated in case of axillary lymph node dissection (85% versus 58%). More patients had definitive surgical treatment consisting of one surgical intervention (87% versus 75%), and left the hospital within 7 days after hospital admission (98% versus 66%). CONCLUSION The clinical audit contributed to improvement of the quality of breast cancer care in the Midwestern part of the Netherlands between 2002 and 2008.

Neo)adjuvant systemic therapy for melanoma

Surgery still is the cornerstone of treatment for patients with stage II and III melanoma, but despite great efforts to gain or preserve locoregional control with excision of the primary tumour, satellites, intransits, sentinel node biopsy and lymphadenectomy, surgery alone does not seem to improve survival any further. Prognosis for patients with high risk melanoma remains poor with 5-year survival rates of 40 to 80%. Only interferon-2b has been approved as adjuvant therapy since 1995, but clinical integration is low considering the high risk-benefit ratio. In recent years systemic targeted- and immunotherapy have proven to be beneficial in advanced melanoma and could be a promising strategy for (neo)adjuvant treatment of patients with resectable high risk melanomas as well. Randomised, placebo- controlled phase III trials on adjuvant systemic targeted- and immunotherapy are currently being performed using new agents like ipilimumab, pembrolizumab, nivolumab, vemurafenib and dabrafenib plus trametinib. In this article we review the literature on currently known adjuvant therapies and currently ongoing trials of (neo)adjuvant therapies in high risk melanomas.

Sentinel node biopsy in melanoma: Current controversies addressed

Sentinel node biopsy (SNB) is the most accurate staging tool for melanoma patients. The procedure is indicated especially for intermediate thickness melanoma (pT2/3). SNB can be of value in thin melanoma (>0.75 mm in thickness), with adverse prognostic factors, and in thick melanomas (pT4), although T4 patients are already at high risk of disease progression. Completion lymph node dissection (CLND) after positive SN yields additional non-sentinel lymph nodes (NSNs) in 20% of cases. Several factors are predictive for NSN positivity, such as primary tumor characteristics and SN tumor burden. The most used and best validated tumor burden parameter is the maximum diameter of the SN metastasis. Others are the microanatomic location of the metastasis in the SN and tumor penetrative depth. These parameters might be used to stratify risk and select patients for either adjuvant treatment trials (diameter >1 mm), or refraining from treatment (minimal SN tumor burden). There is no undisputed evidence for an overall treatment-related benefit for SNB-based management, although benefit has been suggested for a subgroup of node positive patients with intermediate-thickness melanomas. The DeCOG-SLT study failed to demonstrate a survival benefit for CLND after a positive SN. Results of the MSLT-2 and EORTC 1208 (MINITUB) trial, that both assess the role of CLND in SN positive patients have to be awaited. There might be a role for US-FNAC in melanoma staging. New SN visualization techniques can help allow easier identification of SNs in complex areas, shorten operation time and possibly reduce the amount of false-negative SNBs.

The Quality of Staging Non-Small Cell Lung Cancer in the Netherlands: Data From the Dutch Lung Surgery Audit

BACKGROUND Clinical staging of non-small cell lung cancer (NSCLC) determines the initial treatment offered to a patient. The similarity between clinical and pathologic staging in some studies is as low as 50%, and others publish results as high as 91%. The Dutch Lung Surgery Audit is a clinical database that registers the clinical and pathologic TNM of almost all NSCLC patients who undergo operations in the Netherlands. The objective of this study was to determine the accuracy of clinical staging of NSCLC. METHODS Prospective data were derived from the Dutch Lung Surgery Audit in 2013 and 2014. Patients were included if they had undergone a surgical resection for stage IA to IIIB NSCLC without neoadjuvant treatment and had a positron emission tomography-computed tomography scan as part of the clinical workup. Clinical (c)TNM and pathologic (p)TNM were compared, and whether discrepancy was based on tumor or nodal staging was determined. RESULTS From 2,834 patients identified, 2,336 (82.4%) fulfilled the inclusion criteria and had complete data. Of these 2,336, 1,276 (54.6%) were staged accurately, 707 (30.3%) were clinically understaged, and 353 (15.1%) were clinically overstaged. In the understaged group, 346 patients had a higher pN stage (14.8%), of which 148 patients had unforeseen N2 disease (6.3%). In the overstaged group, 133 patients had a cN that was higher than the pN (5.7%). CONCLUSIONS Accuracy of NSCLC staging in the Netherlands is low (54.6%), even in the era of positron emission tomography-computed tomography. Especially accurate nodal staging remains challenging. Future efforts should include the identification of specific pitfalls in NSCLC staging.

Changes in nationwide use of preoperative radiotherapy for rectal cancer after revision of the national colorectal cancer guideline

BACKGROUND The rate of preoperative radiotherapy (RT) for rectal cancer in the Netherlands has been the highest among European countries. Revision of the national guideline on colorectal cancer, officially published in 2014, specifically focussed on the indication for RT and MRI criteria to evaluate mesorectal lymph nodes. The objective of this study was to evaluate implementation of the revised guideline using a national audit. METHODS Data of the Dutch Surgical Colorectal Audit (DSCA) between 2009 and 2014 were used to evaluate RT use and RT regimen for relevant subgroups of cM0 rectal cancer patients, as well as accuracy of pre-operative MRI. RESULTS 14,018 patients were included for analysis. Overall RT use in cT1-4N0-2M0 stage ranged from 81.4% to 84.2% between 2009 and 2013, and decreased to 64.4% in 2014. The absolute decrease in RT use from 2013 to 2014 for cT1N0, cT2N0 and cT3N0 stage was 32.8%, 43.5% and 31.6%, respectively. Short course RT with delayed surgery was used as an alternative to chemoradiotherapy up to 2013 in 30.6% of patients over 80 years, and in 12.1% of patients with an ASA score >2; these percentages increased to 45.8% and 19.9% in 2014, respectively. Specificity of MRI for N-stage decreased from 82.9% in 2009 to 62.9% in 2013, with an increase to 73.2% in 2014. CONCLUSION The revised national guideline on colorectal cancer was rapidly implemented in the Netherlands with a substantial decrease in RT use for low risk resectable rectal cancer, and increased specificity of MRI for N-staging.

Variation in head and neck cancer care in the Netherlands: A retrospective cohort evaluation of incidence, treatment and outcome

BACKGROUND To explore variation in numbers and treatment between hospitals that treat head and neck cancer (HNC) in the Netherlands. MATERIAL AND METHODS Patient, tumor and treatment characteristics were collected from the Netherlands Cancer Registry, while histopathological features were obtained by linkage to the national pathology record register PALGA. Inter-hospital variation in volume, stage, treatment, pathologically confirmed loco-regional recurrence and overall survival rate was evaluated by tumor site. RESULTS In total, 2094 newly diagnosed patients were included, ranging from 65 to 417 patients in participating hospitals treating HNC in 2008. Oral cavity cancer was mainly treated by surgery only, ranging from 46 to 82% per hospital, while the proportion of surgery with (chemo)radiotherapy ranged from 18 to 40%. Increasing age, male sex, and high stage were associated with a higher hazard of dying. In oropharynx cancer, the use of (chemo)radiotherapy varied from 31 to 82% between hospitals. We found an indication that higher volume was associated with a lower overall hazard of dying for the total group, but not by subsite. Low numbers, e.g. for salivary gland, nasopharynx, nasal cavity and paranasal sinus, did not permit all desired analyses. CONCLUSION This study revealed significant interhospital variation in numbers and treatment of especially oropharyngeal and oral cavity cancer. This study is limited because we had to rely on data recorded in the past for a different purpose. To understand whether this variation is unwanted, future research should be based on prospectively collected data, including detailed information on recurrences, additional case-mix information and cause of death.

International benchmarking in oesophageal and gastric cancer surgery: International benchmarking in oesophageal and gastric cancer surgery

Benchmarking on an international level might lead to improved outcomes at a national level. The aim of this study was to compare treatment and surgical outcome data from the Swedish National Register for Oesophageal and Gastric Cancer (NREV) and the Dutch Upper Gastrointestinal Cancer Audit (DUCA).

Abstract P6-06-19: Impact of hospital surgical volume on breast cancer mortality: A population based study in the Netherlands

Background : For some low-volume tumour types hospital surgical volume is associated with better survival. For breast cancer there is still much debate. The aim of this study is to determine to what extent the yearly surgical hospital volume determines the mortality in invasive non-metastatic breast cancer patients. Method : Women diagnosed with primary invasive breast cancer in the period 2001-2005 were selected from the Netherlands Cancer Registry. Hospitals were grouped by their annual volume of surgery for invasive breast cancer. Cox proportional hazard models were performed including all patients with primary non-metastatic breast cancer who underwent breast surgery. Gender, age at diagnosis, morphology, grade, size (pT), number of positive lymph nodes, year of diagnosis and socio economic status (SES) were included as covariates. Follow-up was complete until the 1 th of February 2013. Results : In total 58.982 patients with invasive non-metastatic breast cancer were diagnosed during the period 2001-2005. Hospitals were grouped by volume of surgery: less than 75 (n = 19), 76-100 (n = 30), 101-150 (n = 29), 150-199 (n = 9) and 200 or more (n = 14) surgeries per year. Non-metastatic patients had a 8% higher risk of death in a low volume hospitals than a hospital with >200 surgeries per year (HR 1.08, 95%CI 1.02-1.14). Patient and tumour characteristics like age (HR 1.05, 95%CI 1.05-1.05) and SES (lowest vs highest; HR 1.12, 95%CI 1.07-1.16), grade (low vs high, HR 1.72, 95%CI 1.63-1.82), tumour size (1-2 cm vs 2-5 cm; HR 1.46, 95%CI 1.40-1.51), and a higher number of positive lymph nodes (0 vs 1-3; HR 1.40, 95%CI 1.34-1.46 and 0 vs >10; HR 3.19, 95%CI 3.00-3.39) influenced death to a larger extend than surgical volume. Conclusion : In the Netherlands, surgical hospital volume influences risk of death marginally, and far less than patient and tumour characteristics. No differences in mortality between hospitals with a surgical volume of more than 75 were revealed for invasive non-metastatic breast cancer patients compared to hospitals with more than 200 operations. Over the more recent period of 2007-2012, only 3 hospitals had less than 75 operations on average per year, resulting in an even more comparable mortality between hospitals in future. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-06-19.