Every year, the American Society of Clinical Oncology (ASCO) Annual Meeting brings together cancer researchers, oncologists, and advocates to discuss the latest advances in cancer care. Some studies presented at ASCO may eventually change how colorectal cancer (CRC) is treated. Others help answer important questions patients and families are already asking in clinic.
Here are three CRC updates patients and advocates should be paying attention to at ASCO 2026.
1. BREAKWATER update: Targeted therapy continues improving outcomes in BRAF-mutated metastatic colorectal cancer
One of the most important CRC updates at ASCO GI 2026 came from the phase III BREAKWATER trial, which evaluated encorafenib plus cetuximab and chemotherapy in patients with previously untreated BRAF V600E-mutated metastatic colorectal cancer (mCRC). At this year’s annual meeting, updated results were presented.
Updated results showed that adding the targeted therapy combo to chemotherapy led to a 56% reduction in the risk of disease progression or death for people with previously untreated BRAF V600E-mutant metastatic colorectal cancer compared with standard treatment.
Patients receiving the combination lived significantly longer without their cancer worsening, with a median progression-free survival of 15.2 months versus 8.3 months for standard therapy. At 18 months, nearly 75% of patients on the combination were alive compared with just over 50% in the standard treatment group, and overall survival had not yet been reached at the time of analysis.
The updated findings also confirmed that the regimen remained generally well-tolerated, with no new safety concerns identified.
2. Using ctDNA to guide chemotherapy decisions in CRC
Patients with CRC who had surgery and received chemotherapy afterwards showed very different outcomes depending on how their circulating tumor DNA (ctDNA) changed after about three months of treatment. In a large analysis from the GALAXY study, patients whose ctDNA increased during treatment had extremely high risk of recurrence, while those whose ctDNA became undetectable or stayed negative had much better outcomes.
People who achieved ctDNA clearance or maintained no detectable ctDNA generally didn’t gain additional benefit from extending chemotherapy beyond a shorter duration, suggesting their cancer may already be well controlled. In contrast, patients whose ctDNA decreased but remained detectable appeared to benefit from longer chemotherapy, with improved disease-free survival compared with shorter treatment. However, patients with rising ctDNA didn’t benefit from continuing the same therapy, indicating that treatment change rather than extension may be needed. Overall, these findings suggest ctDNA dynamics could help personalize how long patients need chemotherapy after surgery.
These results are significant because they show ctDNA may help doctors move beyond a “one-size-fits-all” approach to chemotherapy duration and instead tailor treatment intensity based on a patient’s real-time molecular response, potentially improving outcomes while avoiding unnecessary toxicity.
3. ctDNA deepens personalized care for patients with stage II MSS colon cancer
Patients with stage II colon cancer that was mismatch repair–proficient (pMMR) and microsatellite stable (MSS) had better outcomes when treatment decisions were guided by circulating tumor DNA (ctDNA) testing after surgery. ctDNA-positive patients who received chemotherapy had a much lower 3-year recurrence rate compared with those who were observed (19% vs 62%). They also had a higher 3-year disease-free survival rate (77% vs 38%), suggesting chemotherapy significantly reduced the risk of cancer coming back in this high-risk group.
These results highlight that ctDNA can help identify which patients are more likely to benefit from additional (adjuvant) chemotherapy after surgery. While the study didn’t reach statistical significance, likely due to the small number of patients and early trial closure, the findings support ctDNA-guided treatment as a promising strategy to better personalize care in stage II colon cancer.
Why this matters for patients
Large cancer meetings like ASCO can feel overwhelming, especially when headlines begin circulating before patients fully understand what the research may mean for them personally. Not every study will immediately change treatment, and early excitement doesn’t always translate into a new standard of care.
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