The impact of T and N stage on long-term survival of rectal cancer patients in the community.

BACKGROUND AND OBJECTIVES: Use of the TNM staging system has been encouraged for rectal cancer patients. This study examined the impact of T and N stages on long-term survival as well as the performance of associated risk classification systems.
METHODS: Patients who underwent surgery for rectal adenocarcinoma from 1988 to 2004 were identified in the Surveillance, Epidemiology, and End Results (SEER) database. Kaplan-Meier survival analysis was performed for subgroups of patients defined by T and N stage.
RESULTS: For the overall population of 30,826 patients, both T and N stage significantly impacted overall survival (P < 0.001). N stage variably affected survival for subgroups of patients based on T stage, whereas T stage significantly affected survival regardless of N stage. A previously developed risk classification system that assigns one of four risk levels outperformed AJCC group staging in this cohort. Based on long-term outcomes, a modified risk classification system was constructed which was highly prognostic for long-term overall survival (P < 0.001).
CONCLUSIONS: Rectal cancer patients experience widely varying survival rates based on extent of disease. A new risk classification system is proposed that provides better prognostic information than AJCC group staging, suggesting current rectal cancer staging systems may be improved with appropriate revisions.