Impact of Total Lymph Node Count on Staging and Survival After Neoadjuvant Chemoradiation Therapy for Rectal Cancer
- 298 Downloads
Current guidelines recommend that a minimum of 12 lymph nodes (LNs) be dissected to accurately stage rectal cancer patients. Neoadjuvant chemoradiation therapy (CRT) decreases the number of LNs retrieved at surgery. The purpose of this study was to assess the impact of the number of LNs dissected on overall survival (OS) for localized rectal cancer patients treated with neoadjuvant CRT.
Treatment data were obtained on all patients treated for rectal cancer (2000–2013) in the National Oncology Data Alliance™, a proprietary database of merged tumor registries. Eligible patients were treated with neoadjuvant CRT followed by surgery and had complete data on number of positive LNs, number of LNs examined, and treatment dates (n = 4565).
Hazard ratios for OS decreased sequentially with increasing number of LNs examined until a maximum benefit was achieved with examination of eight LNs. On multivariate analysis, age, sex, race, marital status, grade, ypT stage, ypN stage, type of surgery, margin status, presence of pathologically confirmed metastasis at surgery, and number of LNs examined were significant predictors of OS.
Examination of eight or more LNs in rectal cancer patients treated with neoadjuvant CRT resulted in accurate staging and assignment into prognostic groups with an ensuing improvement in OS by stage. This study suggests that eight LNs is the threshold for an adequate lymph node dissection after neoadjuvant CRT.
KeywordsOverall Survival Rectal Cancer Total Mesorectal Excision National Comprehensive Cancer Network Rectal Cancer Patient
- 5.National Comprehensive Cancer Network. NCCN clinical practice guidelines in oncology: rectal cancer. 2013. http://www.nccn.org/professionals/physician_gls/pdf/rectal.pdf. Accessed 31 Dec 2014.
- 14.National Cancer Institute. Surveillance, Epidemiology, and End Results (SEER) Program (www.seer.cancer.gov). SEER*Stat Database: Incidence – SEER 18 Regs Research Data, Nov 2012 Sub (1973-2010) < Katrina/Rita Population Adjustment >—Linked To County Attributes—Total U.S., 1973-2012 Counties, National Cancer Institute, DCCPS, Surveillance Research Program, Surveillance Systems Branch, released September 2013.
- 15.Harrell FE Jr (2014) Regression modeling strategies with applications to linear models, logistic regression, and survival analysis. Springer, New York pp 13–15; 509–522Google Scholar
- 16.Edge SB, Byrd DR, Compton CC, Fritz AG, Greene FL, Trotti A. (eds). (2009) AJCC Cancer Staging Manual. 7th ed. Springer, New York pp 144–166Google Scholar
- 25.Kapiteijn E, Kranenbarg EK, Steup WH, et al. Total mesorectal excision (TME) with or without preoperative radiotherapy in the treatment of primary rectal cancer: prospective randomised trial with standard operative and histopathological techniques. Eur J Surg. 1999;165(5):410–20.PubMedCrossRefGoogle Scholar