Clinical significance of colorectal cancer: Metastases in lymph nodes <5 mm in size

Background: The clinical significance of metastases in small lymph nodes is not known. Our objective was to evaluate possible relationships between the number and size of lymph node metastases and survival after potentially curative colorectal resection. Methods: A retrospective chart review was performed in patients with Dukes' C (any T, N-1-3, M(0)) colorectal cancers from July 31, 1971 to December 31, 1987. Ail specimens underwent the lymph node clearing technique. Statistical analysis was performed with the log rank test and the Cox proportional hazards model. Results: In 77 patients there were 253 (8%) of 3,087 cleared lymph nodes with metastases. One hundred seventy-five (69%) of these metastatic nodes were 5 mm or less in diameter. The distal margin of resection (p = 0.011) and number of positive lymph nodes (p = 0.036) were statistically significant factors influencing overall survival. There was no significant difference in overall survival (p = 0.73) or disease-free survival (p = 0.56) whether the involved lymph nodes were < or > 5 mm in size, Conclusion: Most metastatic lymph nodes were < 5 mm in diameter. Based on our results, the size of lymph node metastases do not affect disease-free or overall survival in colorectal carcinoma.