Short-course Radiation Therapy Followed by Chemotherapy as Preoperative Treatment for Rectal Cancer

Background. Currently, neoadjuvant treatment followed by total mesorectal excision is the standard management for locally advanced rectal cancer. There are varied regimens regarding the combination of neoadjuvant radiotherapy and chemotherapy. In this study, we aimed to report the feasibility and early oncological outcomes of preoperative short-course radiation therapy (SRT) followed by consolidative chemotherapy and delayed surgery in patients with rectal cancer. Materials and Methods. A retrospective review of 39 patients with rectal cancer who underwent neoadjuvant SRT followed by chemotherapy between March 2014 and June 2019 was performed. The regimen of chemotherapy included either mFOLFOX6 or capecitabine and oxaliplatin or oral form 5-fluorouracail alone. Full course chemotherapy was defined as 8 weeks of preoperative chemotherapy after SRT. Results. All the 39 patients included in this study completed SRT, and 32 patients (82.1%) completed full course of neoadjuvant chemotherapy. One of the 32 patients required dose reduction due to general weakness. Six of the seven patients not completing full course of chemotherapy underwent early surgical intervention, and the remaining one patient achieved clinical completed response (cCR) without subsequent surgery. Of all patients, 4 patient (10.3%) achieved cCR and opted to watch-and-wait policy. Thirty-four patients underwent surgery and 3 (8.8%) of them presented with pathological complete response (pCR). No major treatment-related toxicity or para-operative morbidity and mortality presented. Conclusion. SRT followed by neoadjuvant chemotherapy is feasible and well tolerated by patients without significant toxicity. It is a safe regimen for patients with rectal cancer and results in acceptable short-term oncological outcomes.背景：術前輔助性治療後進行直腸全繫膜切除手術為目前對於局部侵犯性直腸癌之標準治療方式。術前輔助性治療中，放療及化療相互搭配的治療選項眾多，本研究目的是展示短程放療後行化療作為直腸癌術前輔助性治療的可行性及短期治療成果。方法：挑選本院2014年3月至2019年6月診斷直腸癌並接受短程放療及化療作為術前輔助性治療的病人進行回溯性研究。分析術前輔助性治療相關副作用、手術方式及併發症、腫瘤臨床病理分期及治療成果。結果：39位納入研究的病人均完整接受短程放療。32位病人接受完整療程之術前化療。4位病人在短程放療及化療後達到腫瘤臨床完全緩解（cCR）並接受等待觀察療法（watch and wait）。34位病人在短程放療及化療後接受手術，其中3位病人達到病理完全緩解（pCR）。未觀察到放化療及手術相關之嚴重併發症。結論：短程放療後行化療作為直腸癌術前輔助性治療是可行且安全的。