Influence of Organ Invasion in Clinical Outcomes for Locally Advanced Rectal Cancer

Aim: To evaluate whether patients with external sphincter invasion have a better prognosis than patients with invasion of other organs.

Patients and methods: Patients with cT4b adenocarcinoma of the rectum were treated with a tri-modality approach, including neo-adjuvant chemoradiotherapy (CRT), surgery and adjuvant chemotherapy. Patients with external sphincter invasion were classified as cT4b1, whereas patients with invasion of other organs as cT4b2. Survival curves were compared for cT4b sub-stage.

Results: Between January 2008 and December 2014, a total of 21 consecutive patients with cT4b disease (14 with cT4b1 and seven with cT4b2) were treated with CRT, followed by surgery and adjuvant chemotherapy. In total, the overall survival rate at 5 years was 57.4%, whereas 5-year disease-free survival was 52%. The 5-year overall survival rates were 65.3% and 44.4% for patients with cT4b1 and cT4b2 disease, respectively.

Conclusion: External sphincter invasion seems to be associated with a better prognosis when compared to primary lesion with extension to other organs.