Analysis of re-recurrent rectal cancer after curative treatment of locally recurrent rectal cancer.

PURPOSE: Substantiating data guiding clinical decision making in locally recurrent rectal cancer (LRRC) is lacking, specifically in target volume (TV) definition for chemoradiotherapy (CRT). A case-by-case review of local re-recurrences (re-LRRC) after multimodal treatment for LRRC was performed, to determine location of re-LRRC and assess whether treatment could have been improved. METHODS: All patients treated with curative intent for LRRC at the Catharina Hospital Eindhoven from October 2016 onwards, in whom complete imaging of (re-)LRRC and radiotherapy was available, were retrieved. Patients were discussed in plenary meetings with expert colorectal surgeons, radiation oncologists and radiologists. Each case was classified based on re-LRRC location, whether it was in accordance with the (current) radiotherapy protocol, and whether multimodal management would have been different in retrospect. RESULTS: Thirty-three cases were discussed. LRRC treatment was deemed suboptimal in 17/33 patients, due to different target volumes (13/17) and/or different surgery (9/17). 15/33 (46 %) of re-LRRC developed in-field of the prior radiotherapy TV, possibly showing RT-resistant disease. Other re-LRRCs developed out-field (n = 5, 15 %), marginally (n = 6, 18 %), or in a combined fashion (n = 7, 21 %). In retrospect, 48 % of cases were irradiated in line with current TV recommendations. TVs of 13/33 cases would have been altered if irradiated today. CONCLUSION: This study highlights room for improvement within current standard-ofcare treatment for LRRC. Different surgical management or TVs may have improved outcome in up to half of discussed cases. Further delineation guideline development, incorporating the results from this study, may improve oncological outcome, specifically local control, for LRRC patients.

Locally recurrent rectal cancer and distant metastases: is there still a chance ofcure?

INTRODUCTION: Patients with locally recurrent rectal cancer (LRRC) generally have poor prognosis, especially those who have (a history of) distant metastases. The aim of this study was to investigate the impact of distant metastases on oncological outcomes in LRRC patients undergoing curative treatment. METHODS: Consecutive patients with surgically treated LRRC between 2005 and 2019 in two tertiary referral hospitals were retrospectively analysed. Oncological survival of patients without distant metastases were compared with outcomes of patients with synchronous distant metastases with the primary tumour, patients with distant metastases in the primary-recurrence interval, and patients with synchronous LRRC distant metastases. RESULTS: A total of 535 LRRC patients were analysed, of whom 398 (74%) had no (history of) metastases, 22 (4%) had synchronous metastases with the primary tumour, 44 (8%) had metachronous metastases, and 71 (13%) had synchronous LRRC metastases. Patients with synchronous LRRC metastases had worse survival compared to patients without metastases (adjusted hazard ratio: 1.56 [1.15-2.12]), whilst survival of patients with synchronous primary metastases and metachronous metastases of the primary tumour was similar as those patients who had no metastases. In LRRC patients who had metastases in primary-recurrence interval, patients with early metachronous metastases had better disease-free survival as patients with late metachronous metastases (3-year disease-free survival: 48% vs 22%, p = 0.039). CONCLUSION: LRRC patients with synchronous distant metastases undergoing curative surgery have relatively poor prognosis. However, LRRC patients with a history of distant metastases diagnosed nearby the primary tumour have comparable (oncological) survival as LRRC patients without distant metastases.