Dr. Axe Wire · Study decoded · health

Short-Course Radiation Plus Immunotherapy Beat Standard Care for Rectal Cancer in Phase 3 Trial

A 231-patient trial found short-course radiation followed by an immune drug and chemotherapy lowered the 3-year risk of progression, recurrence or death.

By Dr. Josh Axe · November 2, 2026 · 1 source · Understand

Photo: Pexels

A phase 3 trial of 231 patients with locally advanced rectal cancer, published October 25, 2026 in The Lancet Oncology, found that short-course radiation followed by the immune drug camrelizumab and chemotherapy lowered the risk of cancer progression, recurrence or death by 67% compared with standard long-course chemoradiotherapy.

91.3% vs 77.4%event-free

67%lower progression risk

231patients, 9 hospitals

3-yearfollow-up

Researchers in China ran a phase 3 trial called UNION across nine hospitals, enrolling 231 adults aged 18 to 75 with untreated locally advanced rectal cancer.

One group received short-course radiotherapy (25 Gy over five treatments), then two cycles of the checkpoint inhibitor camrelizumab with chemotherapy, then surgery, more chemotherapy and up to 15 more cycles of camrelizumab. The other group received standard long-course chemoradiotherapy, chemotherapy and surgery. After a median follow-up of about 36.7 months in the camrelizumab group and 34.7 months in the standard group, 91.3% of the camrelizumab group were alive with no progression, recurrence or spread at 3 years, versus 77.4% of the standard group, a 67% lower risk.

Serious treatment-related side effects occurred in 19% of the camrelizumab group versus 13% of the standard group. One treatment-related death occurred in the camrelizumab group, from septic shock linked to chemotherapy rather than camrelizumab; none occurred in the standard group.

Checkpoint inhibitors like camrelizumab block a signal some cancer cells use to hide from immune attack, letting immune cells find and destroy them. Radiation can make tumors more visible to the immune system, which may explain the lower rate of progression seen in the combination group.

3-Year Event-Free Survival: Short-Course Radiation + Camrelizumab vs. Standard Care

The Lancet Oncology, 2026, Tao et al.

This is a prespecified interim analysis of a key secondary endpoint in a still-active trial, so longer-term survival numbers aren't available yet. The trial was open-label, meaning patients and doctors knew which treatment was given, and it compared against long-course chemoradiotherapy rather than newer total neoadjuvant approaches.

Dr. Axe’s Take

Radiation and a checkpoint drug don't address what drove the cancer. In general, diet, excess weight and inactivity are established risk factors for colorectal cancer, and no arm of this trial touched them. The 91% versus 77% result at three years is still a real gain. The cost: up to 15 more cycles of camrelizumab after surgery, and serious treatment-related side effects ran 19% versus 13%. What I'd watch for is immune-related side effects, since checkpoint drugs can turn the immune system on the thyroid, gut, skin or lungs. And listen, never stop or change a medication on your own. Make that change with your practitioner.

— Dr. Axe

Take the Cellular Health Quiz →

Study summary

Who: 231 adults aged 18-75 with untreated locally advanced rectal cancer, nine hospitals in China.
Design: Open-label, randomized phase 3 trial (UNION); 113 in the experimental arm, 118 on standard care.
Dose: Short-course radiotherapy (25 Gy, 5 fractions), then camrelizumab (200 mg) plus chemotherapy, vs. long-course chemoradiotherapy (50.4 Gy, 28 fractions) plus chemotherapy.
Primary result: 3-year event-free survival: 91.3% (experimental) vs. 77.4% (standard care); hazard ratio 0.33.
Secondary: Serious treatment-related side effects: 19% (experimental) vs. 13% (standard). Treatment-related deaths: one (experimental, chemotherapy-related) vs. none.
Funding / conflicts: Funded by Union Hospital, a Hubei Province research programme and Jiangsu Hengrui Pharmaceuticals. Four authors (ZH, RZ, FZ, CH) are Hengrui employees; all other authors declare no competing interests.
Date: Oct 25, 2026