Non-operative Management of Locally Advanced Rectal Adenocarcinoma Using a Watch-and-Wait Approach: A Report of Two Cases.

The rectum constitutes the distal segment of the large intestine, and rectal cancer typically arises through a multistep process in which normal epithelial cells undergo dysplastic transformation, eventually progressing to invasive carcinoma. This progression is often asymptomatic and may take years, making early detection challenging. Consequently, many cases are diagnosed at advanced stages. Management strategies are highly dependent on the stage at diagnosis. For T3N1M0 rectal cancers, current guidelines recommend neoadjuvant chemoradiotherapy followed by surgical resection. However, when the tumor location precludes sphincter-sparing surgery, patients may require a permanent colostomy, significantly affecting quality of life. We present two cases of rectal adenocarcinoma in which patients underwent total neoadjuvant therapy, achieved a complete clinical response, and opted for non-operative management with active surveillance. These cases illustrate the potential role of a non-surgical, observation-based approach in selected patients and emphasize the importance of shared decision-making and individualized treatment planning in rectal cancer care.