The Prognostic Impact of Endoscopic Obstruction on Colorectal Cancer

Abstract

Purpose: The colorectal cancer has better prognosis rather than other gastrointestinal malignancy by the development of operation procedure and adjuvant therapy. But the high-risk patients have a high recurrence rate and a poor prognosis, so more interest and the development of new treatment modality for high-risk patients is needed. Now some high-risk factors of the colorectal cancer - lymph node metastasis and lymphatic/vascular invasion – were difficult to estimate preoperatively. The colon obstruction is considered to be a factor which is predictable preoperatively and helpful for patient. There were fewer studies about oncologic outcome of partial or endoscopic colon obstruction than complete colon obstruction, so we investigate the prognostic impact of endoscopic obstruction on colorectal cancer. Materials and Methods: Retrospective analysis of 317 patients with surgically resected stage II and III colorectal cancer in Korea Uinversity Guro Hospital from 1st January 2003 to 31st December 2006 was performed for preoperative colon obstruction and postoperative prognosis. Statistical analysis was performed using SPSSⓇ 12.0. Chi-square test and t-test were used for comparing each variables. OS analysis was performed using Kaplan-Meier curves with log-rank testing. P < 0.05 was considered statistically significant. Results: Gender (Male : Female) of whole patients was 1.4:1. Mean age was 62.0(year). Comparison of clinical features and pathologic findings according to the presence of obstruction demonstrated a significant difference in size, location, infiltration, and preoperative CEA (carcinoembryogenic antigen), yet showed no major differences in age, sex, the timing of surgery, and lymph node metastasis. When the left colon was compared with the right colon while excluding the rectum, difference was found between the sizes of the tumor, but no difference was found in the presence of obstruction. According to the comparison based on the shape of the tumor, 41.1% of the obstructive colon cancer was infiltrating or encircling, and these findings were observed in 23.4% of nonobstructive colon cancer (p<0.05). There were 69 recurrences during the monitoring, and the 5-year diseasefree survival rate for stage II and stage III were 85.5% and 70.7%, respectively. Comparing the disease-free survival rate according to the location of the lesion and presence of obstruction, it showed no difference in stage III colon and rectal cancer, but a significant difference was found in stage II rectal cancer. When compared according to the types of obstruction, the 5-year disease-free survival rates for no obstruction, endoscopic obstruction, and complete obstruction were 77.2%, 70.9%, and 67.1%, respectively. There were no differences between them. Conclusion: Endoscopic obstruction is a significant risk factor for recurrence in stage II rectal cancer compared to colon cancer and for those patients, adjuvant treatment such as pre-operative radiotherapy is needed.