Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2023 Dec 30;13(12):e076866.
doi: 10.1136/bmjopen-2023-076866.

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

Barbara M Geubels  1   2   3 , Baukelien van Triest  4 , Femke P Peters  4 , Monique Maas  5 , Geerard L Beets  1   3 , Corrie A M Marijnen  4   6 , Petra A Custers  1 , Harm J T Rutten  2 , Jaqueline C M Theuws  7 , An-Sofie E Verrijssen  7 , Jeltsje S Cnossen  7 , Jacobus W A Burger  2 , Brechtje A Grotenhuis  8
Affiliations

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

Barbara M Geubels et al. BMJ Open. .

Abstract

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.

Keywords: Clinical trials; Colorectal surgery; Gastrointestinal tumours; Radiation oncology.

PubMed Disclaimer

Conflict of interest statement

Competing interests: None declared.

Figures

Figure 1
Figure 1
Flowchart for the OPAXX study for patients with a clinical good response after neoadjuvant (chemo)radiotherapy for rectal cancer.
See this image and copyright information in PMC

References

    1. Habr-Gama A, Perez RO, Nadalin W, et al. . Operative versus Nonoperative treatment for stage 0 distal Rectal cancer following Chemoradiation therapy: long-term results. Ann Surg 2004;240:711–7; 10.1097/01.sla.0000141194.27992.32 - DOI - PMC - PubMed
    1. van der Valk MJM, Hilling DE, Bastiaannet E, et al. . Long-term outcomes of clinical complete responders after Neoadjuvant treatment for Rectal cancer in the International watch & wait database (IWWD): an international Multicentre Registry study. Lancet 2018;391:2537–45. 10.1016/S0140-6736(18)31078-X - DOI - PubMed
    1. Hupkens BJP, Martens MH, Stoot JH, et al. . Quality of life in Rectal cancer patients after Chemoradiation: watch-and-wait policy versus standard resection - A matched-controlled study. Dis Colon Rectum 2017;60:1032–40. 10.1097/DCR.0000000000000862 - DOI - PubMed
    1. Maas M, Beets-Tan RGH, Lambregts DMJ, et al. . Wait-and-see policy for clinical complete responders after Chemoradiation for Rectal cancer. J Clin Oncol 2011;29:4633–40. 10.1200/JCO.2011.37.7176 - DOI - PubMed
    1. Custers PA, van der Sande ME, Grotenhuis BA, et al. . Long-term quality of life and functional outcome of patients with Rectal cancer following a watch-and-wait approach. JAMA Surg 2023;158:e230146. 10.1001/jamasurg.2023.0146 - DOI - PMC - PubMed

Publication types

Associated data

LinkOut - more resources