LAUSR

Key Points Question Can a previously validated clinical calculator be adapted to estimate the risk of rectal cancer recurrence dynamically at different time points for patients who defer surgery after complete response to neoadjuvant therapy? Findings In this cohort study of 302 patients with stage II or III rectal cancer, recurrence-free survival for patients in the watch-and-wait cohort at 12 months from completion of total neoadjuvant therapy resembled recurrence-free survival in patients who had undergone surgery and had a pathologic complete response. Model performance improved over time, and the concordance index increased from 0.62 at 3 months after total neoadjuvant therapy to 0.66 at 12 months. Meaning These findings suggest that this calculator, which helps show how risk of recurrence changes with time, could help patients decide whether to proceed with surgery after neoadjuvant therapy or to safely hold off and could help physicians adjust follow-up intervals optimally over time.