Prognostic Factors Affecting Survival and Recurrence of Patients with pT1 and pT2 Colorectal Cancer

Abstract

Data on the prognostic factors of survival and recurrence in patients with colorectal cancers confined to the bowel wall (T1 and T2) are limited. The aim of the present study was to determine factors that might predict the survival and recurrence of patients who had T1 and T2 colorectal cancers. All patients with T1 or T2 colorectal cancers who underwent resection in the Department of Surgery, University of Hong Kong Medical Centre, from 1996 to 2004 were included. Analysis was made from the prospectively collected database. Predictive factors for lymph node metastasis and prognostic factors were analyzed. A total of 265 patients (144 men) with the median age of 71 years (range: 33-93 years) were included. Seventy-two patients had T1 cancers (rectal cancer n = 44; colon cancer n = 28; p = 0.89) and 193 patients suffered from T2 cancer (rectal n = 120; colon cancer n = 73). The overall incidence of lymph node metastasis was 12.7% (5.6% for T1 cancer and 14.5% for T2 cancer; p = 0.021). The presence of lymphovascular permeation was the only independent factor associated with a higher incidence of lymph node metastasis on multivariate analysis (odds ratio: 1.48, 95% CI: 1.44-13.47, p = 0.009). There were no significant differences in disease-free 5-year survival (T1 = 84.6%; T2 = 81.1%) and 5-year cancer-specific survival in patients with T1 and T2 tumors (T1 = 90.2%; T2 = 90.6%). Patients with lymph node metastasis had a significantly shorter disease-free 5-year survival (p < 0.001) and 5-year cancer-specific survival (p = 0.002) when compared with those having a negative lymph node status. Cox proportional hazards model analysis showed that lymph node status was the only significant independent factor predicting cancer-specific survival (hazard ratio: 3.52, 95% CI: 1.60-7.71, p = 0.002) and disease-free survival (hazard ratio: 3.42, 95% CI: 1.75-6.69, p < 0.001). Presence of lymphovascular permeation would have a significant higher chance of lymph node metastasis. Positive lymph node status was predictive of poorer survival in patients with T1 or T2 colorectal cancers. For those cancers with positive lymphovascular permeation, radical surgery is recommended.