Dual immunotherapy brings complete response in rectal cancer case

A 54-year-old man in Taichung has had no detectable rectal tumour or affected lymph node lesions for two years after four rounds of dual immunotherapy, while retaining his rectum and bowel function. The complete response allowed him to avoid chemotherapy, radiotherapy and surgery, according to his medical team.

He had endured unexplained buttock pain for four months despite rehabilitation and acupuncture. Bleeding with bowel movements, together with a family history of cancer, eventually prompted further investigation. Doctors diagnosed stage III mid-to-low rectal cancer. Cancerous lymph nodes were pressing on nerves and causing the pain.

Biomarker testing found two features, MSI-high and deficient mismatch repair, indicating that the tumour might respond to immunotherapy. After a multidisciplinary review, the team used PD-1 and CTLA-4 inhibitors as the initial treatment, aiming both to control the disease and preserve the organs. Follow-up MRI, colonoscopy and blood tests found that the primary tumour and lymph node lesions had disappeared.

This approach applies only to selected patients with the right biomarkers and clinical profile. Continued close surveillance remains essential even after a complete response. The case also highlights why persistent symptoms such as rectal bleeding or altered bowel habits deserve timely medical assessment, especially for people with a family history of cancer.