Comparison of Tumor Regression Grade Systems for Locally Advanced Rectal Cancer After Multimodality Treatment
Open Access
- 23 September 2014
- journal article
- research article
- Published by Oxford University Press (OUP) in JNCI Journal of the National Cancer Institute
- Vol. 106 (10)
- https://doi.org/10.1093/jnci/dju248
Abstract
Tumor regression grade (TRG) is a measure of histopathological response of rectal cancer to neoadjuvant chemoradiation and is associated with outcomes. Several TRG systems are used: Mandard (5,3-tier), Dowrak/Rödel (5,3-tier), Memorial Sloan Kettering Cancer Center (MSKCC), and American Joint Committee on Cancer (AJCC) Cancer Staging. A single measure of rectal cancer response would assist in comparing results across institutions, and in designing future rectal cancer studies. In this study, the predictive accuracies of the various published classification schemes are compared. Review of a prospective database identified 563 patients with locally advanced rectal cancer (T3/4 and/or N1) treated between 1998 and 2007 with long-course chemoradiation and total mesorectal excision. TRG was determined by measuring proportion of tumor mass replaced by fibrosis. Patients were classified into TRG schemes, which were compared by analyzing association with recurrence and survival using concordance index. Probabilities of recurrence-free survival were estimated using the Kaplan-Meier method. All statistical tests were two-sided. All TRG systems were predictive of recurrence. Concordance indices of the three-tier Mandard, three-tier Dowrak/Rödel, three-tier MSKCC, and four-tier AJCC systems were: 0.665, 0.653, 0.683, and 0.694, respectively (higher number = better prediction). The AJCC system more accurately predicted recurrence than the three-tier Mandard (P = .002) or Dowrak/Rödel (P = .006) and had a higher concordance index than MSKCC, although this did not reach statistical significance (P = .068). When classifying rectal cancer response to chemoradiation, the AJCC Staging Manual (7th edition) system is most accurate and should be adopted as the standard.Keywords
This publication has 21 references indexed in Scilit:
- Prognostic importance of Mandard tumour regression grade following pre-operative chemo/radiotherapy for locally advanced rectal cancerEuropean Journal Of Cancer, 2011
- Pathologic Complete Response of Primary Tumor Following Preoperative Chemoradiotherapy for Locally Advanced Rectal CancerAnnals of Surgery, 2010
- Complete pathologic response after preoperative rectal cancer chemoradiotherapyAnz Journal of Surgery, 2009
- Preoperative radiotherapy versus selective postoperative chemoradiotherapy in patients with rectal cancer (MRC CR07 and NCIC-CTG C016): a multicentre, randomised trialThe Lancet, 2009
- Prognostic Value of Pathologic Complete Response After Neoadjuvant Therapy in Locally Advanced Rectal Cancer: Long-Term Analysis of 566 ypCR PatientsInternational Journal of Radiation Oncology*Biology*Physics, 2008
- Pathologic stage is most prognostic of disease‐free survival in locally advanced rectal cancer patients after preoperative chemoradiationCancer, 2008
- Pathologic response assessed by Mandard grade is a better prognostic factor than down staging for disease‐free survival after preoperative radiochemotherapy for advanced rectal cancerColorectal Disease, 2007
- The relationship of pathologic tumor regression grade (TRG) and outcomes after preoperative therapy in rectal cancerInternational Journal of Radiation Oncology*Biology*Physics, 2005
- Preoperative versus Postoperative Chemoradiotherapy for Rectal CancerNew England Journal of Medicine, 2004
- Pathologic assessment of tumor regression after preoperative chemoradiotherapy of esophageal carcinoma. Clinicopathologic correlationsCancer, 1994