A phase III randomised trial on the addition of a contact X-ray brachytherapy boost to standard neoadjuvant chemo-radiotherapy for organ preservation in early rectal adenocarcinoma: 5 year results of the OPERA trial.

Background: The OPERA trial has shown that a contact X-ray brachytherapy 50 kV (CXB) boost with neoadjuvant chemoradiotherapy (NCRT) can increase organ preservation (OP) rate for early rectal adenocarcinoma (ADK) of low-mid rectum. We report the results after 5 years of follow-up.

Patients And Methods: OPERA was a multicentre, phase III trial that included operable patients (pts), with cT2-cT3b low-mid rectal ADK, tumours <5 cm, cN0 or cN1 <8 mm.

'Folfirinox' chemotherapy combined with contact x-ray brachytherapy 50kVp and 'CAP50' chemoradiotherapy aiming at organ preservation for selected intermediate distal-middle cT2-T3 rectal cancers: A feasibility study.

Purpose: The standard treatment of T2-T3 rectal adenocarcinoma is radical proctectomy by total mesorectal excision often combined with some neoadjuvant treatment. To reduce morbidity of this surgery, organ preservation strategy using various combination of radiotherapy, chemotherapy and local excision is gaining interest. Some randomized trials have proven the feasibility of such approaches.

The safety and efficacy of total mesorectal excision (TME) surgery following dose-escalation: Surgical outcomes from the organ preservation in early rectal adenocarcinoma (OPERA) trial, a European multicentre phase 3 randomised trial (NCT02505750).

Aim: Nonsurgical treatment with chemoradiotherapy for rectal cancer is gaining interest as it avoids total mesorectal excision (TME) surgery and stoma. The OPERA trial aims to evaluate whether dose escalation with contact X-ray brachytherapy (CXB) boost improves organ preservation compared to external beam radiotherapy (EBRT) boost. It has been suggested that dose escalation adversely affects surgical outcomes and therefore we report outcomes following TME in OPERA at 36 months.

Neoadjuvant chemoradiotherapy with radiation dose escalation with contact x-ray brachytherapy boost or external beam radiotherapy boost for organ preservation in early cT2-cT3 rectal adenocarcinoma (OPERA): a phase 3, randomised controlled trial.

Background: Organ preservation after reaching clinical complete response on neoadjuvant therapy is gaining interest for rectal cancers, although the role of radiation dose escalation is still not known. We aimed to determine whether a contact x-ray brachytherapy boost, following or preceding neoadjuvant chemoradiotherapy, increases the probability of 3-year organ preservation for patients with early rectal cancers.

Methods: OPERA was a multicentre, open-label, phase 3 randomised controlled trial done at 17 cancer centres that included operable patients, aged 18 years or older, with cT2, cT3a, or cT3b adenocarcinoma of low-mid rectum, tumours of less than 5 cm in diameter, and cN0 or cN1 smaller than 8 mm.