A combination of therapies reduces the risk of recurrence of resistant colon cancer by up to 50%.

Colon cancer is already the most common cancer in Spain , with more than 40,000 new diagnoses in 2024 alone according to data from the Spanish Association Against Cancer (AECC) , and is the second leading cause of death.

If detected early, the prognosis is relatively good , and we currently have a wide variety of tools to combat it, including surgery, radiotherapy, immunotherapy, and chemotherapy. The choice of specific method depends primarily on the characteristics of the case and the patient.

A combination of immunotherapy and chemotherapy

Now, a new study presented at the American Society of Clinical Oncology (ASCO) annual convention and reported on its website has found that adding immunotherapy to chemotherapy treatments for stage 3 colon cancer with mismatch repair deficiency (dMMR, a type of colon cancer characterized by a difficulty for cells to repair genetic damage that has a worse response to chemotherapy than other types of cancer) after surgery could reduce a patient’s risk of recurrence and death by about 50%.

These are the conclusions drawn by the authors of a phase 3 clinical trial (and therefore the last step necessary for the possible approval of a treatment for human use) that recruited 712 patients with a mean age of 64 years with stage 3 dMMR colon cancer (the stage of cancer development in which it has already spread to the lymph nodes, but not to other parts of the body) who had already received surgery.

What these researchers did was divide these patients into two groups. One received a type of chemotherapy called mFOLFOX6, commonly used in colorectal cancer, and the other received mFOLFOX6 along with an immunotherapy drug called atezolizumab . They then compared the patients' outcomes over the following three years.

Up to 50% more disease-free survival

In this way, they observed that patients who had received the combination of therapies had a lower probability of suffering relapses in the following three years (up to 50% lower).

Due to the advanced nature of the study, the authors argue that these data are sufficient to modify first-line treatment for this type of cancer and incorporate their new approach, which they say will result in a better prognosis for patients.

Additionally, longer-term studies will need to be conducted in the coming years to help understand the statistical benefits of this treatment method over longer periods. This will allow us to assess the durability of the improved survival and the safety of the approach over time.

References

AECC. Colon cancer. Accessed online at https://www.contraelcancer.es/es/todo-sobre-cancer/tipos-cancer/cancer-colon on June 11, 2025.

Frank A. Sinicrope et al. Randomized trial of standard chemotherapy alone or combined with atezolizumab as adjuvant therapy for patients with stage III deficient DNA mismatch repair (dMMR) colon cancer (Alliance A021502; ATOMIC). ASCO (2025). Accessed online at https://www.asco.org/abstracts-presentations/ABSTRACT502396 on June 11, 2025.

Do you want to receive the best content to take care of your health and feel good? Sign up for our free newsletter.