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TOPLINE
In a phase 2/3 trial of patients with early- or intermediate-stage rectal cancer, long-course chemoradiotherapy (CRT) was more effective than short-course radiotherapy (RT) for organ preservation. At 12 months, total mesorectal excision (TME)-free survival was 78.5% vs 60.6% with CRT vs short-course RT.
METHODOLOGY
- TME remains standard care for most patients with low-risk rectal cancer, but it can cause substantial functional and quality-of-life issues. STAR-TREC is the first randomized trial to directly compare long-course CRT and short-course RT as rectum-preserving strategies, alongside a radical surgery comparator.
- The phase 2/3, open-label trial was conducted across 37 sites in Europe and enrolled 503 patients, all of whom had biopsy-confirmed rectal adenocarcinoma < 40 mm, staged as mrT1-T3bN0 on MRI. Patients chose between TME or organ preservation; those who chose the latter were randomly assigned to CRT or short-course RT.
- Patients allocated to CRT received 50 Gy in 25 fractions with oral capecitabine 825 mg/m2 twice daily on RT days. Those allocated to short-course RT received 25 Gy in 5 fractions without consolidation chemotherapy.
- This interim analysis included 409 participants in the modified intention-to-treat population (163 treated with CRT, 168 with RT, and 78 with primary surgery). It focused on short-term outcomes at 12 months. The trial’s primary outcome is organ preservation at 30 months.
TAKEAWAY
- At 12 months, TME-free survival was higher with long-course CRT than with short-course RT, at 78.5% vs 60.6% (hazard ratio, 1.90; 95% CI, 1.29-2.81).
- The difference was driven by a higher rate of clinical complete response at 16-20 weeks with CRT (64% vs 36% with RT), as well as less residual ypT2-3 disease (15% vs 37%).
- There were fewer grade 3 or worse adverse events with the organ-preservation approaches than with TME, at 8% vs 19%. The most common included gastrointestinal disorders (2% with CRT, 4% with RT, and 8% with TME) and procedural complications (2%, 3%, and 6%, respectively).
- There were no notable differences in non-regrowth pelvic tumor control, metastasis-free survival, non-regrowth disease-free survival, or overall survival between the CRT and RT groups.
IN PRACTICE
“These early results support a response-adapted organ-preservation approach, with [long-course] CRT appearing more effective than [short-course] RT at 12 months,” the study authors wrote. They stressed, however, the need for longer follow-up to determine whether these early findings translate into durable organ preservation without compromising oncologic safety.
SOURCE
The study, led by Simon P. Bach, of University College London, London, England, was published online in The Lancet Oncology.
LIMITATIONS
The trial’s partially randomized patient-preference design introduced potential selection bias. Follow-up for this analysis was intentionally short and not intended to define long-term functional or oncologic outcomes. The response assessment was timed from the start of RT, rather than completion.
DISCLOSURES
The study was funded by Cancer Research UK, Stand Up to Cancer, the Dutch Cancer Society, the Danish Cancer Society, and other sources. Bach and a co-author reported financial relationships with various companies, including Intuitive Surgical Sarl, GSK, and Roche Diagnostics, outside of the submitted work. Full disclosures are noted in the original article.
This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.
