Fei-Long Ning1, Jun-Peng Pei2, Nan-Nan Zhang3, Jun Wang1, Hong-Guang Quan1, Zu-Bing Mei4, Xian-Tao Zeng5,6, Masanobu Abe7, Chun-Dong Zhang8,9. 1. Department of General Surgery, Xuzhou Hospital of Traditional Chinese Medicine, Xuzhou, People's Republic of China. 2. Department of Gastrointestinal Surgery, The Fourth Affiliated Hospital of China Medical University, Shenyang, People's Republic of China. 3. State Key Laboratory of Cancer Biology, Institute of Digestive Diseases, Xijing Hospital, Fourth Military Medical University, Xi'an, People's Republic of China. 4. Department of Anorectal Surgery, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, People's Republic of China. 5. Center for Evidence-Based and Translational Medicine, Zhongnan Hospital of Wuhan University, Wuhan, People's Republic of China. 6. Department of Evidence-Based Medicine and Clinical Epidemiology, The Second Clinical College of Wuhan University, Wuhan, People's Republic of China. 7. Division for Health Service Promotion, University of Tokyo, Tokyo, Japan. 8. Department of Gastrointestinal Surgery, The Fourth Affiliated Hospital of China Medical University, Shenyang, People's Republic of China. zhangchundong2007@126.com. 9. Department of Gastrointestinal Surgery, Graduate School of Medicine, University of Tokyo, Tokyo, Japan. zhangchundong2007@126.com.
Abstract
PURPOSE: To investigate the correlation between number of retrieved lymph nodes (rLNs) and prognosis and further ascertain the optimal number of rLNs with a beneficial survival impact in patients with pN0 colon cancer. METHODS: The Surveillance, Epidemiology, and End Results (SEER) database was searched for pN0 colon cancer cases. X-Tile software and Kaplan-Meier survival analysis were applied to determine the optimal number of rLNs based on the minimal probability (P) value and the largest χ2 value. Univariate analyses and Cox proportional hazard regression model were used to investigate the relationship between rLN number and overall survival. Multiple analyses were conducted to assess the prognostic predictive ability of the identified optimal rLN cut-off value under different stratifications. Nomograms were established based on the independent prognostic factors selected by the multivariate analysis to predict 3- and 5-year overall survival rates of pN0 patients. RESULTS: A total of 6269 pN0 colon cancer patients who underwent surgical therapy were finally included for analysis. Harvest of at least 18 lymph nodes was determined as the optimal rLN number. This cut-off rLN value (< 18 versus ≥ 18) was identified as an independent prognostic factor (P < 0.001) of overall survival via multivariate analysis. Similar findings were obtained in patients with retrieval of at least 12 lymph nodes (18 > rLNs ≥ 12 versus rLNs ≥ 18) stratified into several groups. CONCLUSIONS: The number of rLNs was identified as an independent prognostic factor for pN0 colon cancer. Retrieval of at least 18 lymph nodes was associated with favorable prognosis in patients with pN0 colon cancer, and should, therefore, be regarded as an alternative cut-off value for survival analysis.
PURPOSE: To investigate the correlation between number of retrieved lymph nodes (rLNs) and prognosis and further ascertain the optimal number of rLNs with a beneficial survival impact in patients with pN0 colon cancer. METHODS: The Surveillance, Epidemiology, and End Results (SEER) database was searched for pN0 colon cancer cases. X-Tile software and Kaplan-Meier survival analysis were applied to determine the optimal number of rLNs based on the minimal probability (P) value and the largest χ2 value. Univariate analyses and Cox proportional hazard regression model were used to investigate the relationship between rLN number and overall survival. Multiple analyses were conducted to assess the prognostic predictive ability of the identified optimal rLN cut-off value under different stratifications. Nomograms were established based on the independent prognostic factors selected by the multivariate analysis to predict 3- and 5-year overall survival rates of pN0 patients. RESULTS: A total of 6269 pN0 colon cancerpatients who underwent surgical therapy were finally included for analysis. Harvest of at least 18 lymph nodes was determined as the optimal rLN number. This cut-off rLN value (< 18 versus ≥ 18) was identified as an independent prognostic factor (P < 0.001) of overall survival via multivariate analysis. Similar findings were obtained in patients with retrieval of at least 12 lymph nodes (18 > rLNs ≥ 12 versus rLNs ≥ 18) stratified into several groups. CONCLUSIONS: The number of rLNs was identified as an independent prognostic factor for pN0 colon cancer. Retrieval of at least 18 lymph nodes was associated with favorable prognosis in patients with pN0 colon cancer, and should, therefore, be regarded as an alternative cut-off value for survival analysis.