A Comparative Study On Clinical Pathological And Prognosis Between Proximal And Distal Colon Cancer

Objective:To compare the difference on clinical characteristics of histopathology between proximal and distal colon cancer, so to provide scientific evidence for clinical diagnosis and treatment, meanwhile, to lay the foundation for the pathogenesis of proximal and distal colon cancer in the further.Methods:We retrospect the medical records of712patients who diagnosed as primary colon cancer, all patients were diagnosed and treated in the Xiangya hospital of College of Central South University from January2006to January2010. Data on age, gender, initial symptoms, histopathology, clinical characteristics, and clinical stages and so on were collected by questionnaires. Survival information was collected by telephone survey. All the data were inputted into compute by using Epidata3.0and statistical analysis were conducted by using SPSS16.0Statistical Soft Package. Ratio used for descriptive analysis. Analysis of categorical data was performed by Chi-square test, survival analysis was determined by the Kaplan-Meier and Long-rank method, Cox proportional hazard regression analysis was used to assess long-term survival outcomes. Results:1. A total of712cases of medical records were reviewed with distal and proximal colon cancer were307(43.1%) and405(56.9%), respectively.604patients were follow-up by telephone, follow-up rate was84.8%.2. There were more females patients among proximal colon cancer than that among distal colon cancer (p=0.008); and the patients whose BMI (body mass index)≥28kg/m2were more among distal colon cancer than that among proximal colon cancer (p<0.001).3. The initial symptoms of proximal colon cancer were common in abdominal pain and abdominal distension; while defecate habit change and intestinal obstruction were common in distal colon cancer.4. The ratio of tumor size=5cm was higher in proximal colon cancer than distal colon cancer (p<0.001). The ratios of infiltrating tumor was higher in distal colon cancer; while mass tumor were higher in proximal colon cancer (p<0.001). The ratios of poorly differentiated adenocarcinoma were higher in proximal colon cancer; while well differentiated adenocarcinoma were higher in distan colon cancer (p<0.001); The lymphatic metastasis and liver metastasis rates were higher in proximal colon cancer than in distal colon cancer (p=0.014and p=0.003).5. The positive rates of serum-CEA and serum-CA199were higher in proximal colon cancer than that in distal colon cancer (p<0.001; p=0.010).6. The1-year survival rates of distal and proximal colon cancer were88.9%and86.0%, respectively (p=0.279); the3-year survival rates of distal and proximal colon cancer were65.3%and56.7%, respectively (p=0.033); the5-year survival rates of distal and proximal colon cancer were56.7%and46.0%, respectively (p=0.045). There were no significance on5-year survival rates between distal and proximal colon cancer (stage I)(p=0.891), while significance were found in stages II> Ⅲ、Ⅳ(p<0.05).7. Cox proportional hazard regression analysis showed tumor location, lymphatic metastasis, liver metastasis, and pathological types were main factors influencing survival time.Conclusion:Proximal colon cancer have higher malignant degree and easier to lymphatic metastasis, liver metastasis and has a worse prognosis than distal colon cancer. Genetic gene and ecology factors may contribute to those differences.