O-017 The prognostic relevance of MRI Tumor Regression Grade versus histopathological complete response in rectal cancer

AbstractPre-operative chemoradiotherapy (CRT) followed by surgical resection is still the standard treatment for locally advanced low rectal cancer. Nowadays new strategies are emerging to treat patients with a complete response to pre-operative treatment, rendering the optimal management still controversial and under debate. The primary aim of this study was to obtain a snapshot of tumor regression grade (TRG) distribution after standard CRT. Second, we aimed to identify a correlation between clinical tumor stage (cT) and TRG, and to define the accuracy of magnetic resonance imaging (MRI) in the restaging setting. Between January 2017 and June 2019, a cross sectional multicentric study was performed in 22 referral centers of colon-rectal surgery including all patients with cT3-4Nx/cTxN1-2 rectal cancer who underwent pre-operative CRT. Shapiro–Wilk test was used for continuous data. Categorical variables were compared with Chi-squared test or Fisher’s exact test, where appropriate. Accuracy of restaging MRI in the identification of pathologic complete response (pCR) was determined evaluating the correspondence with the histopathological examination of surgical specimens.In the present study, 689 patients were enrolled. Complete tumor regression rate was 16.9%. The “watch and wait” strategy was applied in 4.3% of TRG4 patients. A clinical correlation between more advanced tumors and moderate to absent tumor regression was found (p = 0.03). Post-neoadjuvant MRI had low sensibility (55%) and high specificity (83%) with accuracy of 82.8% in identifying TRG4 and pCR.Our data provided a contemporary description of the effects of pre-operative CRT on a large pool of locally advanced low rectal cancer patients treated in different colon-rectal surgical centers.

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Development of a novel apoptosis-based tumor regression grade to assess the efficacy of preoperative chemoradiotherapy for rectal cancer: a retrospective single-center study

International Journal of Clinical Oncology ◽

10.1007/s10147-021-01948-2 ◽

2021 ◽

Author(s):

Kosuke Ozaki ◽

Kazushige Kawai ◽

Hiroaki Nozawa ◽

Kazuhito Sasaki ◽

Koji Murono ◽

...

Keyword(s):

Rectal Cancer ◽

Tumor Regression ◽

Preoperative Chemoradiotherapy ◽

Tumor Regression Grade ◽

Single Center ◽

Single Center Study ◽

Regression Grade ◽

Center Study

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Rectal cancer – current treatment strategy and the tumor regression grade evaluation after neoadjuvant therapy in patients who underwent surgery at the I. Department of Surgery, General University Hospital in Prague between 2012 and 2016

10.33699/pis.2021.100.2.74-82 ◽

2021 ◽

Vol 100 (2) ◽

Keyword(s):

Rectal Cancer ◽

Neoadjuvant Therapy ◽

Tumor Regression ◽

Neoadjuvant Treatment ◽

Neoadjuvant Chemoradiotherapy ◽

Current Treatment ◽

University Hospital ◽

Tumor Regression Grade ◽

Oncological Treatment ◽

Regression Grade

Introduction: The article contains a summary of the issues of staging and therapy with an emphasis on the neoadjuvant treatment and associated tumor regression grade with the analysis of our own group of patients. Methods: Retrospective analysis of patients with rectal cancer who underwent a surgery at the 1st Department of Surgery – Thoratic, Abdominal and Injury Surgery; First Faculty of Medicine, Charles University in Prague and General University Hospital in Prague, Czech Republic, focusing on those who underwent neoadjuvant chemoradiotherapy and their pathologists evaluated tumor regression grade after the resection. Results: The group consists of 161 patients operated on between 2012 and 2016. 47 patients underwent neoadjuvant oncological treatment with further evaluation of the tumor regression grade by a pathologist, a scoring system according to Ryan was used. A complete pathological response was elicited in 10.4% of patients, no response in 35.4% of patients, and partial tumor regression in 54.2%. Conclusion: Although there is a difference in our results compared to foreign publications, the proportion of patients remains comparable. Studies evaluating the advantages versus disadvantages of neoadjuvant therapy will certainly follow, and the question of the suitability of surgical treatment as the only curative solution is partially raised.

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