Photodynamic Therapy as an Adjunct During Stent-Bridged Neoadjuvant Management of Obstructive Colon Cancer: A Case-Based Narrative Review.

Abstract

Malignant left-sided large-bowel obstruction remains a high-risk presentation that often requires urgent decompression. Self-expanding metal stents (SEMS) can convert an emergency to an elective operation and may create a window for staging, multidisciplinary planning, and (in selected patients) neoadjuvant systemic therapy. Photodynamic therapy (PDT) is a light-activated, locally delivered ablative modality that has been used historically for palliation or local control of colorectal and pelvic recurrences, but its role in contemporary management of obstructing colon cancer remains investigational. We present an anchoring case of obstructive rectosigmoid adenocarcinoma managed with endoscopic SEMS placement, interval endoluminal PDT, followed by systemic neoadjuvant therapy and curative resection with a pathologic complete response. Using this case as a framework, we review established management pathways for obstructing left-sided colon cancer (emergency surgery, diversion, and SEMS as a bridge to surgery), summarize evidence and guideline positions on SEMS and neoadjuvant therapy for resectable colon cancer, and synthesize the limited clinical literature describing PDT in colorectal malignancy. We emphasize that, given the multimodal sequence and existing evidence base, PDT should be viewed as a potential adjunct to-rather than a replacement for-SEMS, systemic therapy, or standard oncologic surgery. This case illustrates technical feasibility and conceptual integration, but does not establish efficacy; prospective study is needed to define patient selection, timing, and safety.