Int J Colorectal Dis (2012) 27:1077–1085 Table 3 Univariate analysis of overall survival and cancer spe- cific survival in patients with colorectal resection Male Female Colon Rectum Laparoscopic Open Stage I Stage II Stage III Age >70 Age≤70 Presence of medical diseases No Yes Perineural invasion No Yes Lymphovascular permeation No Yes Differentiation Well Moderate Poor No complications Complications Overall survival p values Cancer specific survival p values 66.3% 71.6% 70.9% 66.4% 74.7% 65.5% 83.0% 72.1% 58.1% 63.3% 73.9% 71.9% 66.2% 71.0% 44.0% 72.7% 55.8% 76.2% 68.7% 61.2% 71.6% 59.1% 0.042 0.344 <0.001 <0.001 <0.001 0.042 <0.001 <0.001 0.003 <0.001 76.2 79.1 81.5 73.7 81.9 75.2 93.6% 81.7% 66.8% 77.5 77.8 76.5 78.3 80.6 46.5 82.3 62.6 90.0 77.7 64.9 79.8 70.1 1083 0.222 0.005 0.002 <0.001 0.398 0.324 <0.001 <0.001 <0.001 <0.001 important as many patients are elderly and death might be due to other medical diseases, which might be related to the operation. We demonstrated both a significantly better over- all and cancer specific survivals in patients who underwent laparoscopic resection. The approach of surgery was shown to be an independent significant factor of both overall and cancer specific survival. This confirmed our previous find- ings on the improved survival in patients with laparoscopic Table 4 Multivariate analysis of factors affecting overall survival Open operation Male Age >70 Presence of medical diseases Stage of disease Differentiation Perineural invasion Lymphovascular invasion Postoperative complication Risk ratio 1.36 1.20 1.72 1.10 1.56 1.26 1.55 1.23 1.60 p value 0.006 0.077 <0.001 0.357 <0.001 0.095 0.003 0.079 <0.001 95% confidence interval 1.093–1.700 0.980–1.461 1.399–2.110 0.897–1.351 1.335–1.832 0.961–1.651 1.161–2.075 0.976–1.548 1.299–1.969 colon and rectal resection with a larger patient population. The improvement occurred mainly both stage II and stage III cancer and occurred both in colon and rectal cancer. This is different from multicenter randomized studies [7–9], which showed equivalent survival in patients with open and laparoscopic resection. We postulated that most of these randomized trials such as the COST trial [4] were initially planned as non-inferiority studies and were not powered to show the difference in survival. Table 5 Multivariate analysis of factors affecting cancer specific survival Open operation Stage of disease Differentiation Perineural invasion Lymphovascular invasion Postoperative complication Rectal cancer Risk ratio 1.32 1.83 1.66 1.89 1.37 1.57 1.28 p value 0.048 <0.001 0.002 <0.001 0.024 0.001 0.048 95% confidence interval 1.005–1.738 1.489–2.246 1.207–2.288 1.372–2.611 1.044–1.811 1.215–2.041 1.003–1.635