Tailoring adjuvant chemotherapy by circulating tumor DNA (ctDNA) in older patients with stage II-III colon cancer

Abstract

In most western countries, the median age of patients with CRC is around 70years. Although the benefit of adjuvant chemotherapy has been established in stage III colon cancer, it remains controversial in patients with stage II disease. Colon cancer treatment in older adults follows the same basic concepts as in younger patients. However, for older patients, who may have age-related organ function decline and comorbid conditions that may limit life expectancy, special attention must be paid to the risks of chemotherapy, including treatment-related toxicities and quality of life issues. Long-term toxicities are particular concerns in older patients who received adjuvant chemotherapy. In the high-risk frail patient population, avoiding adjuvant therapies in patients with negative circulating tumor DNA (ctDNA) group, could prevent treatmentrelated toxicities while preserving the quality of life. In the treatment paradigm of earlystage colon cancer, the promise of ctDNA lies in its potential to detect minimal residual disease following resection of the primary tumor, allowing precise risk assessment and ctDNA-guided adjuvant therapy. Future studies will determine whether this technique may tailor treatment for patients in the adjuvant setting. Subgroup analyses by age may yield data on the use of ctDNA in older patients. Integration of the ctDNA approach to geriatric assessment may complete the missing piece of the puzzle when making adjuvant treatment decisions in older patients with colon cancer.