Background: It is generally known that long duration of untreated colonic cancer can lead to obstruction.Another contributing factor might be tumor growth rate. The present study was conducted to compare tumorgrowth rates related to lymph node metastasis of the obstructive and non-obstructive colonic cancers. Methods:169 patients who underwent operations for colonic cancer were studied retrospectively. Patient and tumorcharacteristics as well as clinical outcomes were analyzed. Results: 94 patients (55.6%) presented with obstructedcolonic cancers, and 75 (44.4%) with non-obstructed, 78.7% and 57.3%, respectively having a tumor size greaterthan 5 cm. On logistic regression analysis, both groups had similar lymph node metastasis rates (OR=1.6; 95%CI=0.8-3.2). Conclusion: No relations between obstruction and tumour size or lymph node metastasis werefound. Thus, obstructions only occur because of other factors and do not contribute to tumor growth. Utilizingeffective screening programs to determine obstructions is recommended.
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