OPERA: surgery may be avoided with adequate therapy in rectal cancer

The 38-month follow-up data of the phase 3 OPERA trial showed that non-surgical treatment is feasible for patients with distal-middle, cT2-cT3a-b rectal cancer (RC). In patients who need surgery, this treatment can be administered without comprising the chance of a cure.

The OPERA trial (NCT02505750) randomised 142 patients with cT2-cT3a-b RC 1:1 to external beam chemoradiotherapy (EBCRT) with capecitabine and external beam radiotherapy (EBRT) boosts of 9Gy, 5 fractions, every 5 days (arm A) or to EBCRT followed by targeted radiotherapy using contact X-ray brachytherapy 50 kV (CXB), 90 Gy, 3 fractions, every 4 weeks (arm B) [1]. Prof. Arthur Sun Myint (Clatterbridge Cancer Centre, UK) presented the results.

After 24 weeks, the investigators observed a clinical complete response in 92% of the patients in arm B and in 64% of the patients in arm A. After a median follow-up time of 38.2 months, 46 patients had received surgery in arm A, either total mesorectal excision (TME), or local excision, compared with 20 patients in arm B. In addition, the TME rate was 39% in arm A and 19% in arm B (HR 0.36; P=0.004). Importantly, the organ preservation rates in patients with tumours <3 cm was 63% in arm A and 97% in arm B (HR 0.072; P=0.01) and the 3-year overall survival rates with organ preservation were 57% in arm A and 79% in arm B (P=0.0026).

“In short, non-surgical treatment was feasible for well selected patients (T2-T3a-b) and those who needed surgery could be saved without a decreased chance of cure,” concluded Prof. Sun Myint. Contact X-ray is, however, not feasible everywhere.

1. Sun Myint A, et al. Do nonoperative modality (NOM) treatments of rectal cancer compromise the chance of cure? Final surgical salvage results from OPERA phase 3 randomised trial (NCT02505750). Abstract 6, ASCO GI 2023, 19–21 January, San Francisco, CA, USA.

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Posted on 17 March, 2023