Matthew D Hall1, Timothy E Schultheiss2, David D Smith3, Marwan G Fakih4, Joseph Kim5, Jeffrey Y C Wong2, Yi-Jen Chen2. 1. Department of Radiation Oncology, City of Hope National Medical Cancer, Duarte, CA, USA. mhall@coh.org. 2. Department of Radiation Oncology, City of Hope National Medical Cancer, Duarte, CA, USA. 3. Division of Biostatistics, City of Hope National Medical Cancer, Duarte, CA, USA. 4. Department of Medical Oncology and Therapeutics Research, City of Hope National Medical Cancer, Duarte, CA, USA. 5. Department of Surgery, City of Hope National Medical Cancer, Duarte, CA, USA.
Abstract
PURPOSE: 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. METHODS: 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). RESULTS: 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. CONCLUSIONS: 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.
PURPOSE: Current guidelines recommend that a minimum of 12 lymph nodes (LNs) be dissected to accurately stage rectal cancerpatients. 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 cancerpatients treated with neoadjuvant CRT. METHODS: 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). RESULTS: 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. CONCLUSIONS: Examination of eight or more LNs in rectal cancerpatients 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.
Authors: Stefan Münch; Daniel Habermehl; Ayman Agha; Claus Belka; Stephanie E Combs; Renate Eckel; Helmut Friess; Alexander Gerbes; Natascha C Nüssler; Wolfgang Schepp; Roland M Schmid; Wolfgang Schmitt; Gabriele Schubert-Fritschle; Bernhard Weber; Jens Werner; Jutta Engel Journal: Strahlenther Onkol Date: 2017-10-25 Impact factor: 3.621