Improving the local excision strategy for rectal cancer after chemoradiotherapy: Surgical and oncological results.

INTRODUCTION: Local excision (LE) for good responders after chemoradiotherapy (CRT) for rectal cancer is oncologically safe. Although the GRECCAR 2 trial did not demonstrate any advantages in morbidity, it provided useful information for optimising patient selection. This study assessed the impact of these results on our practice by focusing on the evolution of our selection criteria and management modalities for these patients over 10 years. METHODS: Data were collected using our retrospective database of 110 patients who underwent LE after CRT for low and middle rectal cancer between 2010 and 2022 before (Group 1) and after (Group 2) consideration of the GRECCAR 2 trial results. RESULTS: The pretherapeutic selection criteria remained stable after the GRECCAR 2 trial, although in Group 2, completion total mesorectal excision (TME) for ypT2 tumours with favourable tumour regression grade was abandoned, improving the organ preservation rate at 1 year from 63.3 % to 91.8 % (p < 0.01). The operative time and length of stay after LE were reduced by half in Group 2 (p < 0.01). The intention-to-treat rate for severe morbidity was also halved, but was not significant (8.2 % vs. 16.3 %, p = 0.24). Among patients with a 3-year follow-up data, disease-free survival was comparable between Group 1 (89.8 %) and Group 2 (85.4 %) (p = 0.51) with one locoregional recurrence in each group (2.0 % vs. 2.1 %, p = 1). CONCLUSION: LE is a safe and effective strategy when performed in a "high-volume" centre. Improved methods for assessing tumour response and the selection criteria for completion TME enhanced surgical outcomes without compromising oncological outcomes.

Multiparametric Magnetic Resonance Imaging in the follow-up of non-muscle-invasive bladder tumors after intravesical instillations: a promising tool.

PURPOSE: The standard follow-up for non-muscle-invasive bladder cancer is based on cystoscopy. Unfortunately, post-instillation inflammatory changes can make the interpretation of this exam difficult, with lower specificity. This study aimed to evaluate the interest of bladder MRI in the follow-up of patients following intravesical instillation. METHODS: Data from patients who underwent cystoscopy and bladder MRI in a post-intravesical instillation setting between February 2020 and March 2023 were retrospectively collected. Primary endpoint was to evaluate and compare the diagnostic performance of cystoscopy and bladder MRI in the overall cohort (n = 67) using the pathologic results of TURB as a reference. The secondary endpoint was to analyze the diagnostic accuracy of cystoscopy and bladder MRI according to the appearance of the lesion on cystoscopy [flat (n = 40) or papillary (n = 27)]. RESULTS: The diagnostic performance of bladder MRI was better than that of cystoscopy, with a specificity of 47% (vs. 6%, p < 0.001), a negative predictive value of 88% (vs. 40%, p = 0.03), and a positive predictive value of 66% (vs. 51%, p < 0.001), whereas the sensitivity did not significantly differ between the two exams. In patients with doubtful cystoscopy and negative MRI findings, inflammatory changes were found on TURB in most cases (17/19). The superiority in MRI bladder performance prevailed for "flat lesions", while no significant difference was found for "papillary lesions". CONCLUSIONS: In cases of doubtful cystoscopy after intravesical instillations, MRI appears to be relevant with good performance in differentiating post-therapeutic inflammatory changes from recurrent tumor lesions and could potentially allow avoiding unnecessary TURB.