Management of Stage IV Rectal Cancer with Complete Response in Primary Organ After Total Neoadjuvant Therapy

Abstract Stage IV rectal cancer with clinical complete response (cCR) in the pelvis following total neoadjuvant therapy presents management challenges requiring careful consideration of oncological outcomes, quality of life (QoL), and patient-specific characteristics. This chapter focuses on the practical clinical decision-making encountered when pelvic cCR is observed among patients with distant metastatic disease, specifically addressing whether to proceed with radical resection versus organ-preservation and/or watch and wait strategies. Key topics include assessment of cCR, limitations of current diagnostic modalities in predicting pathological complete response, role of different surgical sequencing approaches in stage IV rectal cancer management, and integration of QoL considerations into treatment decision-making. In this manuscript, we will emphasize the importance of multidisciplinary collaboration and careful patient selection for organ-preservation strategies in this complex patient population.