Watch-and-wait in rectal cancer: A critical appraisal of promise, perils and unresolved contours of organ preservation (Review).

Abstract

Total neoadjuvant therapy has elevated pathological complete response (pCR) rates in locally advanced rectal cancer to unprecedented levels (25-30%), catalyzing interest in organ preservation via the non-surgical 'Watch-and -Wait' (WaW) strategy. Although this approach offers a paradigm shift, its rapid clinical adoption necessitates a critical appraisal of unresolved controversies. The present review synthesizes current evidence to outline the benefits of WaW while critically examining its inherent challenges. A comprehensive analysis interrogates the dualistic nature of WaW. It can provide favorable survival (5-year overall survival of 85% and cancer-specific survival of 94% in the International WaW Database) and meaningful quality-of-life improvements by avoiding radical surgery; concurrently, it embodies substantial risks due to the inherent imprecision of clinical complete response (cCR) assessment (a 10-25% discordance with pCR), a marked local regrowth rate (~25%) and unresolved long-term oncological uncertainties. In the present review it is argued that successful implementation of WaW depends on transcending current limitations through technological integration. Circulating tumor DNA is a promising but still investigational biomarker that may enable dynamic risk stratification; however, its clinical utility requires prospective validation. In conclusion, WaW has evolved from a radical concept to a reasonable, evidence-supported option within a precision oncology framework for a meticulously selected patient cohort, contingent upon rigorous multidisciplinary team assessment and an unwavering, structured surveillance protocol. Its future safety and efficacy will be defined by advances in response assessment, personalized monitoring and long-term outcome data.