Burning Through Colon Cancer: A Game Changer
Immunotherapy could potentially reduce death and recurrence rates of colon cancer by half.
Hey there! Let's talk about colon cancer - yup, the third most common cancer globally, affecting millions yearly. It's treated with various methods including surgery, radiation, immunotherapy, and chemotherapy. However, not all treatments are one-size-fits-all.
Take deficient mismatch repair (dMMR) colon cancer, for instance. This type, covering around 5-15% of cases, is known to be less responsive to chemotherapy than other types. But don't worry, there's a silver lining!
A groundbreaking study presented at the 2025 American Society of Clinical Oncology (ASCO) Annual Meeting has got our backs. Researchers found that adding immunotherapy to chemotherapy after surgery for stage 3 colon cancer may help cut the recurrence and death rate by half!
Atezolizumab: The New Kid on the Block
For this phased-out trial, researchers enlisted 712 participants, aged 64 on average, who had dMMR stage 3 colon cancer. This stage occurs when the cancer makes its way to the lymph nodes, but not other areas.
To clarify, stage 3 colon cancer happens when the cancer has spread to the lymph nodes, but not to distant organs. All study participants had undergone surgery to have their cancer removed and still had cancer cells in their lymph nodes.
Fascinatingly, participants were split into two groups - one received just chemotherapy for colon cancer, while the other got the standard chemotherapy, mFOLFOX6, combined with atezolizumab.
Atezolizumab targets a specific protein in cancer cells called PD-L1. PD-L1's job is to help cancer cells sneak past the immune system. By binding and blocking PD-L1, atezolizumab puts the cancer cells right under the spotlight for the immune system to attack.
The Peacekeeper: A Sweet 50% Reduction
At the study's conclusion, researchers found participants receiving chemotherapy with immunotherapy had a 50% decrease in cancer recurrence and death - referred to as disease-free survival (DFS) - compared to those who only received chemotherapy.
"The findings from our study represent a major advance in the adjuvant treatment of dMMR stage 3 colon cancer and will now change the treatment for this type of cancer," says Frank Sinicrope, MD, an oncologist at the Mayo Clinic in Minnesota and lead author of this study, in a press release.
"It's extremely rewarding to be able to offer our patients a new treatment regimen that can reduce the risk of recurrence and improve their chances of survival," he adds.
Long-term Data and Biomarkers: A Matter of Time
Medical News Today spoke with Glenn S. Parker, MD, FACS, FASCRS, vice chairman of surgery and chief of colorectal surgery at Hackensack Meridian Jersey Shore University Medical Center in New Jersey, about this study. Parker commented that his initial reaction to these findings was a strong sense of hope.
"The use of atezolizumab, an immune checkpoint inhibitor, alongside standard chemotherapy in stage III dMMR colon cancer represents a significant step forward in the care of our patients," Parker explained. "Patients with dMMR colon cancer often have a distinct tumor biology that affects how they respond to chemotherapy. Although they generally have a better prognosis, recurrence still occurs, and current treatments may not be optimal for this group."
Parker said he would like to see extended follow-up from the clinical trial to evaluate long-term survival and recurrence data. Additionally, he emphasized the importance of further studies to explore whether immunotherapy could eventually reduce the length of time for both adjuvant chemotherapy/immunotherapy in some dMMR patients, particularly those with high immune activation profiles.
"Biomarker analyses and quality-of-life assessments will also be critical in determining which patients benefit the most from combined therapy and how best to integrate this approach into standard of care," he added.
Forging Ahead: Personalized Colon Cancer Treatment
Medical News Today also spoke with Wael Harb, MD, a board-certified hematologist and medical oncologist at MemorialCare Cancer Institute at Orange Coast and Saddleback Medical Centers in Orange County, CA, about this research. He expressed genuine excitement about the trial's results.
"Colon cancer is one of the most common and deadly cancers worldwide," he continued. "Even after surgery, many patients - especially those with stage III disease - face a real risk that their cancer will return. For people with dMMR tumors, traditional chemotherapy doesn't always offer enough protection. What makes this group unique is that their tumors are especially responsive to immunotherapy. So finding new ways - like this study - to harness the immune system gives us a much better shot at keeping the cancer from coming back."
Harb explained that the most important next step for this research is to see this approach integrated into treatment guidelines, so doctors everywhere can offer it to eligible patients.
"I'd also like to see longer-term follow-up data to confirm the durability of benefit and monitor safety over time. And looking ahead, it would be exciting to explore whether immunotherapy could also help patients with earlier-stage disease - or even be used instead of chemotherapy in some cases. Ultimately, this study opens the door to more personalized and effective treatments for colon cancer," he added.
Collectively, these findings suggest a game-changing approach for colon cancer treatment, offering hope and improvement in the battle against this deadly disease. Stay tuned for more as research continues to evolve and bring us closer to a future where cancer is no longer a death sentence.
- The immune system plays a crucial role in the treatment of medical conditions like cancer, including colorectal cancer, which is one of the most common globally.
- In oncology, immunotherapy is used to boost the immune system's ability to fight cancer cells, and recent studies have shown promising results, particularly for deficient mismatch repair (dMMR) colorectal cancer.
- A groundbreaking study presented at the 2025 ASCO Annual Meeting found that adding immunotherapy to chemotherapy after surgery for stage 3 colorectal cancer may reduce the recurrence and death rate by half.
- Atezolizumab, an immunotherapy drug that targets a specific protein in cancer cells called PD-L1, has shown significant potential in this context, improving treatment outcomes for dMMR stage 3 colon cancer patients.
- As research continues, there is growing hope for more personalized and effective treatments for colorectal cancer, potentially leading to a future where cancer is no longer a death sentence.
