Predicting complete response: is there a role for non-operative management of rectal cancer?

Pre-operative chemoradiotherapy followed by a total mesorectal excision (TME) is the standard of care for patients with locally advanced (stage II or III) rectal cancer. Approximately 20% of patients may achieve a pathologic complete response after chemoradiation therapy (CRT), which has been shown to be associated with better oncologic outcomes. Whether surgery can be avoided in this population is an area of active investigation. Recent studies demonstrated feasibility and safety of non-operative management in patients with clinical complete response (cCR) after chemoradiotherapy. In this article, we set out to review the current data on non-operative management and to identify areas requiring further investigation, including improvement in imaging for reassessment after CRT and identifying the optimal time frame for restaging. As the field moves forward with non-operative management in select patients with rectal cancer, there continues to be a need to better understand the prognostic factors and biomarkers that may more accurately characterize patients who are qualified for this "wait-and-see" approach and thereby avoid overtreatment, potentially leading to improvements in long-term quality of life.