The prognostic value of the number of lymph nodes removed in patients with node-negative colorectal cancer.

BACKGROUND: To investigate the prognostic significance of the number of lymph nodes removed in colorectal cancer (CRC) patients with no metastatic lymph node. PATIENTS AND METHODS: The clinicopathological data of 461 CRC patients was analyzed. In order to compare the survival of patients who had fewer lymph nodes removed versus the survival of patients who had 1-3 metastatic lymph node(s), a separate group of 74 N1 disease patients were also included in the study. All patient data were collected prospectively. Kaplan-Meier method was used for calculation and plotting of the survival curves of the patient groups, and log-rank test was used for the comparison of the survival curves. RESULTS: Cancer-specific survival (CSS) rates of patients who had 1-7 lymph node(s) and 8-11 lymph nodes removed were significantly worse than those who had 12 or more lymph nodes removed (p = 0.006 and p = 0.037, respectively), while CSS was not significantly different between those who had 1-7 versus 8-11 lymph node(s) removed (p = 0.647); this grouping had independent prognostic significance in Cox analysis (p = 0.006). CSS of patients with N1 disease was not significantly different from those who had 1-7 and 8-11 lymph node(s) removed (p = 0.312 and p = 0.165, respectively), while it was significantly worse than CSS of patients who had 12 or more lymph nodes removed (p = 0.001). CONCLUSION: In colorectal cancer patients whose removed lymph nodes are non-metastatic, removal of at least 12 lymph nodes will determine the lymph node status reliably.

The impact of primary tumor resection on overall survival in patients with colorectal carcinoma and unresectable distant metastases: a prospective cohort study.

BACKGROUND: To compare the patients with primary colorectal carcinoma (CRC) and non-resectable distant metastases with or without primary colorectal tumor resection as a primary treatment in terms of postoperative mortality and overall survival (OS). PATIENTS AND METHODS: The clinicopathological data of 188 CRC patients with non-resectable distant metastases was analyzed. All patient data were collected prospectively. Colorectal tumor was resected in 121 patients (64.3%). Kaplan-Meier method was used for calculation and plotting of the OS curves of the patient groups, and log-rank test was used for the comparison of the survival curves. The relative importance of the prognostic features was investigated using the Cox proportional hazards model. RESULTS: In the whole series and in the patient group undergoing emergency surgical intervention, mortality rate was lower in patients having colorectal tumor resection compared with non-resected patients, with differences approaching the significance level (p = 0.072 and p = 0.076, respectively). Median OS time was significantly longer in resection group (11.0 months), compared with non-resection group (5.5 months) (p < 0.001); in the multivariate Cox analysis colorectal tumor resection had independent prognostic significance (p < 0.001). CONCLUSION: Resection of colorectal tumor in primary CRC patients with non-resectable distant metastasis gives significant survival advantage without increasing postoperative mortality compared with non-resection.