Organ preservation in patients with a good clinical response after neoadjuvant (chemo)radiation for rectal cancer: optimization of treatment strategies and defining the role of additional contact x-ray brachytherapy versus extending the waiting interval and local excision.

Phase 2

Recruiting

• Conditions: rectal adenocarcinoma; rectal cancer; 10017991; 10017998

• Registration Number: NL-OMON52264
• Lead Sponsor: Antoni van Leeuwenhoek Ziekenhuis

Brief Summary

Not available

Detailed Description

Not available

Study Timeline

• Results First Posted: 1900-01-01
• Last Update Posted: 9 April 2024

Recruitment & Eligibility

• Status: Recruiting
• Sex: Not specified
• Target Recruitment: 168

Inclusion Criteria

• histologically verified adenocarcinoma above the dentate line and within 10cm
of the anal verge;
• neoadjuvant short-course radiotherapy for patients with 1) IRC and delayed
re-sponse evalation according to the Dutch national guidelines (cT1-3, cN1-2
lymph nodal status, no involved MRF or cT3c-d, N0-1 lymph nodal status without
pres-ence of significant distant metastases) without full dose chemotherapy in
the inter-val (e.g. Rapido-scheme) or 2) LARC due to comorbidity or frailty; OR
• neoadjuvant long-course radiotherapy (chemoradiation) for patients with 1)
LARC according to the Dutch national guidelines (cT4 tumour, cN2 lymph nodal
status, lateral lymph node involvement, and/or involved MRF, without the
presence of significant distant metastases) or 2) early rectal cancer or IRC
and a strong wish for organ preservation;
• clinically near-complete response or a small residual tumour mass <3 cm;
• technically feasible to perform both treatment options (contact x-ray
brachythera-py or local excision);
• age >18 years;
• written informed consent.

Exclusion Criteria

• neoadjuvant or induction chemotherapy prior or adjacent to (chemo)radiation,
e.g. patients with a Rapido or M1-scheme are not eligible;
• radiation dose >50.4 Gy or boost dose on the primary tumour;
• presence of suspicious lymph nodes (yN1/N2) at first response evaluation;
• residual tumour >= 3cm or over half of the circumference of the rectal lumen;
• patients who are unable to undergo contact x-ray brachytherapy or local
excision;
• patients who cannot tolerate a completion- or salvage-TME because of
comorbidi-ty or frailty;

Study & Design

• Study Type: Interventional
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
<p>The primary endpoint of the OPAXX study reflects the efficacy of both<br /><br>additional treatment options: the rate of successful organ preservation<br /><br>(defined as an in-situ rectum, no defunctioning stoma and absence of active<br /><br>locoregional cancer failure) at one year following randomisation in rectal<br /><br>cancer patients with a good, but not complete clinical response after<br /><br>(chemo)radiation. For patients with a good but not complete clinical response<br /><br>after (chemo)radiation who are not eligible for randomisation in the OPAXX<br /><br>study an observational cohort study is conducted (OPAXX registration study).</p><br>

Secondary Outcome Measures

Name	Time	Method
<p>Secondary endpoints are related to toxicity and morbidity of the two additional<br /><br>treatment options in the randomisation study, as well as to oncological and<br /><br>functional outcomes at one, two and five years of follow-up. </p><br>