The incorporation of ICT in neoadjuvant regimens for locally recurrent rectal cancer is a promising strategy.

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Background The optimal treatment for patients with locally recurrent rectal cancer (LRRC) is controversial. The aim of this study was to investigate different treatment strategies in two leading tertiary referral hospitals in Europe. Methods All patients who underwent curative surgery for LRRC between January 2003 and December 2017 in Catharina Hospital, Eindhoven, the Netherlands (CHE), or Karolinska University Hospital, Stockholm, Sweden (KAR), were studied retrospectively. Available MRIs were reviewed to obtain a uniform staging for optimal comparison of both cohorts. The main outcomes studied were overall survival (OS), local re-recurrence-free survival (LRFS), and metastasis-free survival (MFS). Results In total, 377 patients were included, of whom 126 and 251 patients came from KAR and CHE respectively. At 5 years, the LRFS rate was 62.3 per cent in KAR versus 42.3 per cent in CHE (P = 0.017), whereas OS and MFS were similar. A clear surgical resection margin (R0) was the strongest prognostic factor for survival, with a hazard ratio of 2.23 (95 per cent c.i. 1.74 to 2.86; P < 0.001), 3.96 (2.87 to 5.47; P < 0.001), and 2.00 (1.48 to 2.69; P < 0.001) for OS, LRFS, and MFS respectively. KAR performed more extensive operations, resulting in more R0 resections than in CHE (76.2 versus 61.4 per cent; P = 0.004), whereas CHE relied more on neoadjuvant treatment and intraoperative radiotherapy, to reduce the morbidity of multivisceral resections (P < 0.001). Conclusion In radiotherapy-naive patients, neoadjuvant full-course chemoradiation confers the best oncological outcome. However, neoadjuvant therapy does not diminish the need for extended radical surgery to increase R0 resection rates.

LatLRs impose a major surgical challenge and result in high LRR and low OS. More R0 resections can possibly be achieved with ICT, which is the only factor that can improve LRR and OS.

Background This study aimed to investigate the agreement between magnetic resonance tumour regression grade (mrTRG) and pathological regression grade (pTRG) in patients with locally recurrent rectal cancer (LRRC). Also, the reproducibility of mrTRG was investigated. Methods All patients with LRRC who underwent a resection between 2010 and 2018 after treatment with induction chemotherapy and neoadjuvant chemo(re)irradiation in whom a restaging MRI was available were retrospectively selected. All MRI scans were reassessed by two independent radiologists using the mrTRG, and the pTRG was reassessed by an independent pathologist. The interobserver agreement between the radiologists as well as between the radiologists and the pathologist was assessed with the weighted kappa test. A subanalysis was performed to evaluate the influence of the interval between imaging and surgery. Results Out of 313 patients with LRRC treated during the study interval, 124 patients were selected. Interobserver agreement between the radiologists was fair (k = 0.28) using a two-tier grading system (mrTRG 1–2 versus mrTRG 3–5). For the lead radiologist, agreement with pTRG was moderate (k = 0.52; 95 per cent c.i. 0.36 to 0.68) when comparing good (mrTRG 1–2 and Mandard 1–2) and intermediate/poor responders (mrTRG 3–5 and Mandard 3–5), and the agreement was fair between the other abdominal radiologist and pTRG (k = 0.39; 95 per cent c.i. 0.22 to 0.56). A shorter interval (less than 7 weeks) between MRI and surgery resulted in an improved agreement (k = 0.69), compared with an interval more than 7 weeks (k = 0.340). For the lead radiologist, the positive predictive value for predicting good responders was 95 per cent (95 per cent c.i. 71 per cent to 99 per cent), whereas this was 56 per cent (95 per cent c.i. 44 per cent to 66 per cent) for the other radiologist. Conclusion This study showed that, in LRRC, the reproducibility of mrTRG among radiologists is limited and the agreement of mrTRG with pTRG is low. However, a shorter interval between MRI and surgery seems to improve this agreement and, if assessed by a dedicated radiologist, mrTRG could predict good responders.

Aim Patients with locally recurrent rectal cancer (LRRC) frequently present with either synchronous metastases or a history of metastases. This study was conducted to evaluate whether LRRC patients without metastases have a different oncological outcome compared to patients with a history of metastases treated with curative intent or patients with potentially curable synchronous metastases. Method All consecutive LRRC patients who underwent intentionally curative surgery between 2005 and 2017 in a large tertiary hospital were retrospectively reviewed and categorized as having no metastases, a history of (curatively treated) metastases or synchronous metastases. Patients with unresectable distant metastases were excluded from the analysis. Results Of the 349 patients who were analysed, 261 (75%) had no metastases, 42 (12%) had a history of metastases and 46 (13%) had synchronous metastases. The 3‐year metastasis‐free survival was 52%, 33% and 13% in patients without metastases, with a history of metastases, and with synchronous metastases, respectively (P < 0.001) A history of metastases did not influence overall survival (OS), but there was a trend towards a worse OS in patients with synchronous metastases compared with patients without synchronous metastases (hazard ratio 1.43; 95% CI 0.98–2.11). Conclusion LRRC patients with a history of curatively treated metastases have an OS comparable to that in patients without metastases and should therefore be treated with curative intent. However, LRRC patients with synchronous metastases have a poor metastasis‐free survival and worse OS; in these patients, an individualized treatment approach to observe the behaviour of the disease is recommended.

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Aim Positron emission tomography (PET)/CT can be used to monitor the metabolic changes that occur after intensified treatment with induction chemotherapy and chemo(re)irradiation for locally recurrent rectal cancer (LRRC). This study aimed to analyse the correlation between the PET/CT response and final histopathological outcomes. Methods All LRRC patients who underwent induction chemotherapy prior to surgery between January 2010 and July 2020 and were monitored with pretreatment and post‐treatment PET/CT were included. Visual qualitative analysis was performed, and patients were scored as having achieved a complete metabolic response (CMR), partial metabolic response (PMR) or no response (NR). The histopathological response was assessed according to the Mandard tumour regression (TRG) score and categorized as major (TRG 1–2), partial (TRG 3) or poor (TRG 4–5). The PET/CT and TRG categories were compared, and possible confounders were analysed. Results A total of 106 patients were eligible for analysis; 24 (23%) had a CMR, 54 (51%) had a PMR and 28 (26%) had NR. PET/CT response was a significant predictor of the negative resection margin rate, achieving 96% for CMR, 69% for PMR and 50% for NR. The overall accuracy between PET score and pathological TRG was 45%, and the positive predictive value for CMR was 63%. A longer interval between post‐treatment PET/CT and surgery negatively influenced the predictive value. Conclusion Metabolic PET/CT response evaluation after neoadjuvant treatment proves to be a complementary diagnostic tool to standard MRI in assessing tumour response, and may play a role for treatment planning in LRRC patients.