Tumour regression grading after chemoradiotherapy for locally advanced rectal cancer: A near pathologic complete response does not translate into good clinical outcome

Hendrik A.M. Swellengrebel, Steven L. Bosch, Annemieke Cats, Andrew Vincent, Luc G.H. Dewit, Vic J. Verwaal, Iris D. Nagtegaal, Corrie A.M. Marijnen

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36 Citations (Scopus)

Abstract

Background: After preoperative chemoradiotherapy (CRT) for rectal cancer, clinically undetectable residual tumour deposits or pathologic lymph nodes may remain in the mesorectum. Aim: The aim of this study was to report histopathological effects of CRT and factors affecting outcome in a uniformly treated series of locally advanced rectal cancer (LARC) patients. Methods: Between 2004 and 2008, 107 patients with cT3 (threatening the mesorectal fascia or <5 cm from the anal verge), cT4 or cN2 rectal cancer were treated with preoperative CRT (25 × 2 Gy with capecitabine) and TME 6-8 weeks later. Central histopathological review followed. Tumour regression grade (TRG) was scored in pCR, near-pCR, response and no response. Cox regression was performed to identify prognosticators. Results: The 3-year distant metastasis-free interval, disease-free rate and overall survival rate were 82%, 73% and 87% (median 44 months follow-up). TRG consisted of 20% pCR, 11% near-pCR, 55% response and 14% no response. 6/21 pCR patients harboured nodal metastases. 5/12 near-pCR had ypT3 disease, while 6 harboured node metastases. 5/12 near-PCR patients developed distant metastases. ypN and TRG were powerful outcome discriminators. Conclusion: The high number of near-pCR with ypT3 or ypN1/2 and their poor outcome demonstrates that "watch-and-wait" in LARC patients should be applied with care.

Original languageEnglish
Pages (from-to)44-51
Number of pages8
JournalRadiotherapy and Oncology
Volume112
Issue number1
DOIs
Publication statusPublished - 1 Jan 2014
Externally publishedYes

Keywords

  • Chemoradiotherapy
  • Outcome
  • Rectal cancer
  • Tumour regression grade

ASJC Scopus subject areas

  • Hematology
  • Oncology
  • Radiology Nuclear Medicine and imaging

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