Planned organ preservation for elderly patients with rectal cancer using short course radiotherapy and a contact brachytherapy boost-an International multi-institution analysis

Survival prognostic in different age groups of patients undergoing local versus radical excision for rectal cancer: a study based on the SEER database

Age significantly affects the prognosis of patients with rectal cancer after radical excision (RE), and local excision (LE) is an alternative surgical procedure to RE. To compare the survival prognosis in different age groups of LE versus RE for rectal cancer. Patients diagnosed with rectal adenocarcinoma treated by LE or RE from 2010 to 2017 were obtained from the SEER database. The primary outcomes are 5-year OS and CSS. A total of 11,170 patients were eventually included, and there were 490 patients in LE and RE groups, respectively, after 1:1 propensity score matching. The 5-year OS and CSS after LE were significantly better in < 50 years and 50-66 years groups than in > 66 years group (5-year OS: 95.70% vs 88.40% vs 67.00%, P < 0.001; 5-year CSS: 95.70% vs 96.30% vs 82.60%, P < 0.001). No statistical significance was found for the differences in 5-year OS and CSS between LE and RE in < 50, 50-66, and > 66 years group (P > 0.05). Multivariate analysis showed age > 66 years, poorly differentiated or undifferentiated (Grade III/IV), and tumor size 3 to 5 cm was independent risk factors for 5-year OS after LE; age > 66 years, perineural invasion, and tumor size 3 to 5 cm were the 5-year CSS independent risk factors for after LE. We found that the survival prognosis of younger rectal cancer patients treated with LE was significantly better than older (> 66 years) patients, and the survival prognosis of rectal cancer patients in the three age groups was similar between LE and RE.

Optimisation of Organ Preservation treatment strategies in patients with rectal cancer with a good clinical response after neoadjuvant (chemo)radiotherapy: Additional contact X-ray brachytherapy versus eXtending the observation period and local excision (OPAXX) - protocol for two multicentre, parallel, single-arm, phase II studies

INTRODUCTION

Standard treatment for patients with intermediate or locally advanced rectal cancer is (chemo)radiotherapy followed by total mesorectal excision (TME) surgery. In recent years, organ preservation aiming at improving quality of life has been explored. Patients with a complete clinical response to (chemo)radiotherapy can be managed safely with a watch-and-wait approach. However, the optimal organ-preserving treatment strategy for patients with a good, but not complete clinical response remains unclear. The aim of the OPAXX study is to determine the rate of organ preservation that can be achieved in patients with rectal cancer with a good clinical response after neoadjuvant (chemo)radiotherapy by additional local treatment options.

METHODS AND ANALYSIS

The OPAXX study is a Dutch multicentre study that investigates the efficacy of two additional local treatments aiming at organ preservation in patients with a good, but not complete response to neoadjuvant treatment (ie near-complete response or a small residual tumour mass <3 cm). The sample size will be 168 patients in total. Patients will be randomised (1:1) between two parallel single-arm phase II studies: study arm 1 involves additional contact X-ray brachytherapy (an intraluminal radiation boost), while in study arm 2 the observation period is extended followed by a second response evaluation and optional transanal local excision. The primary endpoint of the study is the rate of successful organ preservation at 1 year following randomisation. Secondary endpoints include toxicity, morbidity, oncological and functional outcomes at 1 and 2 years of follow-up. Finally, an observational cohort study for patients who are not eligible for randomisation is conducted.

ETHICS AND DISSEMINATION

The trial protocol has been approved by the medical ethics committee of the Netherlands Cancer Institute (METC20.1276/M20PAX). Informed consent will be obtained from all participants. The trial results will be published in an international peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NCT05772923.