Michel W.J.M. Wouters

Bio: Michel W.J.M. Wouters is an academic researcher from Netherlands Cancer Institute. The author has contributed to research in topics: Medicine & Melanoma. The author has an hindex of 43, co-authored 293 publications receiving 7571 citations. Previous affiliations of Michel W.J.M. Wouters include Leiden University & Erasmus University Rotterdam.

Completion Dissection or Observation for Sentinel-Node Metastasis in Melanoma

Abstract: BackgroundSentinel-lymph-node biopsy is associated with increased melanoma-specific survival (i.e., survival until death from melanoma) among patients with node-positive intermediate-thickness melanomas (1.2 to 3.5 mm). The value of completion lymph-node dissection for patients with sentinel-node metastases is not clear. MethodsIn an international trial, we randomly assigned patients with sentinel-node metastases detected by means of standard pathological assessment or a multimarker molecular assay to immediate completion lymph-node dissection (dissection group) or nodal observation with ultrasonography (observation group). The primary end point was melanoma-specific survival. Secondary end points included disease-free survival and the cumulative rate of nonsentinel-node metastasis. ResultsImmediate completion lymph-node dissection was not associated with increased melanoma-specific survival among 1934 patients with data that could be evaluated in an intention-to-treat analysis or among 1755 patients in t...

Systematic review and meta-analysis of the volume-outcome relationship in pancreatic surgery.

Abstract: Background: Many studies have shown lower mortality and higher survival rates after pancreatic surgery with high-volume providers, suggesting that centralization of pancreatic surgery can improve outcomes. The methodological quality of these studies is open to question. This study involves a systematic review of the volume–outcome relationship for pancreatic surgery with a meta-analysis of studies considered to be of good quality. Methods: A systematic search of electronic databases up to February 2010 was performed to identify all primary studies examining the effects of hospital or surgeon volume on postoperative mortality and survival after pancreatic surgery. All articles were critically appraised with regard to methodological quality and risk of bias. After strict inclusion, meta-analysis assuming a random-effects model was done to estimate the effect of higher surgeon or hospital volume on patient outcome. Results: Fourteen studies were included in the meta-analysis. The results showed a significant association between hospital volume and postoperative mortality (odds ratio 0·32, 95 per cent confidence interval 0·16 to 0·64), and between hospital volume and survival (hazard ratio 0·79, 0·70 to 0·89).The effect of surgeon volume on postoperative mortality was not significant (odds ratio 0·46, 0·17 to 1·26). Significant heterogeneity was seen in the analysis of hospital volume and mortality. Sensitivity analysis showed no correlation with the extent of risk adjustment or study country; after removing one outlier study, the result was homogeneous. The data did not suggest publication bias. Conclusion: There was a consistent association between high hospital volume and lower postoperative mortality rates with improved long-term survival.

The Dutch Surgical Colorectal Audit

Abstract: Introduction In 2009, the nationwide Dutch Surgical Colorectal Audit (DSCA) was initiated by the Association of Surgeons of the Netherlands (ASN) to monitor, evaluate and improve colorectal cancer care. The DSCA is currently widely used as a blueprint for the initiation of other audits, coordinated by the Dutch Institute for Clinical Auditing (DICA). This article illustrates key elements of the DSCA and results of three years of auditing. Methods Key elements include: a leading role of the professional association with integration of the audit in the national quality assurance policy; web-based registration by medical specialists; weekly updated online feedback to participants; annual external data verification with other data sources; improvement projects. Results In two years, all Dutch hospitals participated in the audit. Case-ascertainment was 92% in 2010 and 95% in 2011. External data verification by comparison with the Netherlands Cancer Registry (NCR) showed high concordance of data items. Within three years, guideline compliance for diagnostics, preoperative multidisciplinary meetings and standardised reporting increased; complication-, re-intervention and postoperative mortality rates decreased significantly. Discussion The success of the DSCA is the result of effective surgical collaboration. The leading role of the ASN in conducting the audit resulted in full participation of all colorectal surgeons in the Netherlands. By integrating the audit into the ASNs' quality assurance policy, it could be used to set national quality standards. Future challenges include reduction of administrative burden; expansion to a multidisciplinary registration; and addition of financial information and patient reported outcomes to the audit data.

Impact of centralization of pancreatic cancer surgery on resection rates and survival

Abstract: Background Centralization of pancreatic surgery has been shown to reduce postoperative mortality. It is unknown whether resection rates and survival have also improved. The aim of this study was to analyse the impact of nationwide centralization of pancreatic surgery on resection rates and long-term survival. Methods All patients diagnosed in the Netherlands between 2000 and 2009 with cancer of the pancreatic head were identified in the Netherlands Cancer Registry. Changes in referral pattern, resection rates and survival after pancreatoduodenectomy were analysed. Multivariable regression analysis was used to assess the impact of hospital volume (20 or more procedures per year) on survival after resection. Results Between 2000 and 2009, 11 160 patients were diagnosed with cancer of the pancreatic head. The resection rate increased from 10·7 per cent in 2000-2004 to 15·3 per cent in 2005-2009 (P < 0·001). No significant difference in survival after resection was observed between the two intervals (P = 0·135), although survival was significantly better in high-volume hospitals (median survival 18 months versus 16 months in low/medium-volume hospitals; P = 0·017). After adjustment for patient and tumour characteristics, high hospital volume remained associated with better overall survival after resection (hazard ratio 0·70, 95 per cent confidence interval 0·58 to 0·84; P < 0·001). Conclusion Centralization of pancreatic cancer surgery led to increased resection rates. High-volume centres had significantly better survival rates. Centralization improves patient outcomes and should be encouraged. More evidence to support the volume outcome relationship

Centralization of Esophageal Cancer Surgery: Does It Improve Clinical Outcome?

Abstract: Background The volume–outcome relationship for complex surgical procedures has been extensively studied. Most studies are based on administrative data and use in-hospital mortality as the sole outcome measure. It is still unknown if concentration of these procedures leads to improvement of clinical outcome. The aim of our study was to audit the process and effect of centralizing oesophageal resections for cancer by using detailed clinical data.

Global Cancer Statistics 2020: GLOBOCAN Estimates of Incidence and Mortality Worldwide for 36 Cancers in 185 Countries.

Abstract: This article provides an update on the global cancer burden using the GLOBOCAN 2020 estimates of cancer incidence and mortality produced by the International Agency for Research on Cancer. Worldwide, an estimated 19.3 million new cancer cases (18.1 million excluding nonmelanoma skin cancer) and almost 10.0 million cancer deaths (9.9 million excluding nonmelanoma skin cancer) occurred in 2020. Female breast cancer has surpassed lung cancer as the most commonly diagnosed cancer, with an estimated 2.3 million new cases (11.7%), followed by lung (11.4%), colorectal (10.0 %), prostate (7.3%), and stomach (5.6%) cancers. Lung cancer remained the leading cause of cancer death, with an estimated 1.8 million deaths (18%), followed by colorectal (9.4%), liver (8.3%), stomach (7.7%), and female breast (6.9%) cancers. Overall incidence was from 2-fold to 3-fold higher in transitioned versus transitioning countries for both sexes, whereas mortality varied <2-fold for men and little for women. Death rates for female breast and cervical cancers, however, were considerably higher in transitioning versus transitioned countries (15.0 vs 12.8 per 100,000 and 12.4 vs 5.2 per 100,000, respectively). The global cancer burden is expected to be 28.4 million cases in 2040, a 47% rise from 2020, with a larger increase in transitioning (64% to 95%) versus transitioned (32% to 56%) countries due to demographic changes, although this may be further exacerbated by increasing risk factors associated with globalization and a growing economy. Efforts to build a sustainable infrastructure for the dissemination of cancer prevention measures and provision of cancer care in transitioning countries is critical for global cancer control.

Multiple Imputation for Nonresponse in Surveys

Abstract: 25. Multiple Imputation for Nonresponse in Surveys. By D. B. Rubin. ISBN 0 471 08705 X. Wiley, Chichester, 1987. 258 pp. £30.25.

Pheochromocytoma and paraganglioma: An endocrine society clinical practice guideline

Abstract: Objective: The aim was to formulate clinical practice guidelines for pheochromocytoma and paraganglioma (PPGL). Participants: The Task Force included a chair selected by the Endocrine Society Clinical Guidelines Subcommittee (CGS), seven experts in the field, and a methodologist. The authors received no corporate funding or remuneration. Evidence: This evidence-based guideline was developed using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system to describe both the strength of recommendations and the quality of evidence. The Task Force reviewed primary evidence and commissioned two additional systematic reviews. Consensus Process: One group meeting, several conference calls, and e-mail communications enabled consensus. Committees and members of the Endocrine Society, European Society of Endocrinology, and Americal Association for Clinical Chemistry reviewed drafts of the guidelines. Conclusions: The Task Force recommends that initial biochemical testing for PPGLs shou...

Toyota production system : beyond large-scale production

Abstract: * Starting from Need* Evolution of the Toyota Production System* Further Development* Genealogy of the Toyota Production System* The True Intention of the Ford System* Surviving the Low-Growth Period