Direct tumor invasion in colon cancer: correlation with tumor spread and survival.

PURPOSE: This study examined the correlation between depth of local invasion in colon cancer and tumor spread and patient survival. METHODS: A cohort of 796 patients with a complete set of TNM staging information following an elective resection for colon cancer was selected. The rates of lymph node and distant metastasis, tumor differentiation, and extramural venous invasion for different tumor (T) categories were compared. The effects of initial tumor (T) category on overall patient survival were studied. RESULTS: The depth of local tumor invasion correlated strongly with nodal involvement (P = 0.0001), rates of extramural venous invasion (P = 0.0002), poor differentiation (P = 0.0001), and distant metastasis (P = 0.0001). Fifty-seven percent of the patients remained lymph node-negative and distant metastasis-negative irrespective of their depth of tumor invasion had no impact on overall survival (P = 0.49). For patients with lymph node or distant metastasis (43 percent), depth of tumor invasion had significant impact on overall survival (P = 0.001). Thirteen percent of T3N1, 33 percent of T3N2, 40 percent of T4N1, and 68.percent of T4N2 cases had distant metastasis at presentation. CONCLUSION: Two types of colon cancer were observed: locally active and tendency to metastasize. For the latter, overall mortality and the risk of metastasis increased with depth of tumor invasion.

Tumor pathology and long-term survival in emergency colorectal cancer.

PURPOSE: Patients who have an emergency operation for colorectal cancer have poorer long-term survival outcomes compared with elective patients. This study was designed to define the role of tumor pathology as a basis for the differences in survival outcomes. METHODS: There were 1,537 elective and 286 emergency patients who had an operation for bowel cancer from 1997 to 2003. Tumor pathology and survival data collected prospectively for these patients were compared by modes of presentation. RESULTS: Excluding 30-day mortality, emergency patients as a whole had a five-year all-cause survival rate of 39.2 percent compared with 64.7 percent for elective patients P<0.0001 they also had more advanced Dukes C and D tumors (P<0.0001). The rates of early T1 and T2 cancers were 4.7 percent for the emergency and 25 percent for the elective group. Emergency cases had more lymph node-positive patients and N2 patients (57.1 vs. 41.8 percent and 26.6 vs. 15.9 percent, respectively; P<0.0001). Curatively resected emergency colon patients again had more advanced Dukes staged tumors (P<0.0001) with a five-year survival rate of 51.6 percent compared with 75.6 percent for elective patients P<0.0001. On stage-for-stage analysis, the survival rates for curatively resected Dukes B and C colon cancers remained worse for emergency patients (P=0.003 and P=0.0002, respectively). Both emergency Dukes B and C groups had more T4 cases (21.5 vs. 10.6 percent; P=0.017 and 26.4 vs. 15 percent; P=0.016, respectively). CONCLUSION: Advanced tumor pathology is a basis for poor long-term survival in emergency colorectal cancers.