International quality assurance project in colorectal cancer-unifying diagnostic and histopathological evaluation

Several European countries are undertaking quality control projects in colorectal cancer. These efforts have led to improvements in survival, but a comparison between different projects reveals questionable results. The aim of this study is the presentation of results from hospitals in three different European countries participating in the International Quality Assurance in Colorectal Cancer (IQACC) project. For this publication, patients with cancer of the colon or rectum treated in 2009 and 2010 and recorded in the IQACC (Germany, Poland and Italy) were analysed. The comparison included number of patients, age, preoperative diagnostics (CT of the abdomen and thorax, MRI, colonoscopy, ultrasound, tumour markers), surgical approach, metastasis, height of rectal cancer and histopathological examination of a specimen (T stage, N stage and MERCURY classification for rectum resection). For short-term outcomes, general complications, wound dehiscence, tumour-free status at discharge, anastomotic leakage and in-hospital mortality were analysed. A total of 12,691 patients (6,756 with colon cancer, 5,935 with rectal cancer) were included in the analysis. Preoperative diagnostics differed significantly between countries. For pT and pN stages, several quality differences could be demonstrated, including missing stages (colon cancer: pT 5.7-12.5 %, pN 2.5-11.0 %; rectal cancer: pT 1.1-5.6 %, pN 1.1-15.5 %). The most relevant differences for short-term outcomes in colon cancer were found in general complications (4.2-22.8 %) and tumour-free status at discharge (74.5-91.7 %). In-hospital deaths ranged between 2.5 and 4.3 % and did not show significant differences. For rectal cancer, the country with the highest percentage of tumours localised less than 4 cm from the anal verge (16.0 %) showed the lowest frequency of amputation (8.5 %). Outcome differences were found for general complications (3.2-18.8 %), anastomotic leakage (0-4.3 %) and tumour-free status at discharge (72.9-87.6 %). In-hospital deaths ranged between 1.1 and 3.2 %. This study demonstrates the feasibility of an international quality assurance project in colorectal cancer. This concept ensures data analysis based on a comparable data input. Differences in preoperative diagnostics, completeness of histopathological evaluation and short-term outcomes for Germany, Poland and Italy might result from disparities in socioeconomic factors and implementation of existing guidelines. Further activities are necessary to warrant the use of common standards in outcome control.