Continuous Effect of Radial Resection Margin on Recurrence and Survival in Rectal Cancer Patients Who Receive Preoperative Chemoradiation and Curative Surgery: A Multicenter Retrospective Analysis

Publication date: Available online 14 March 2017
Source:International Journal of Radiation Oncology*Biology*Physics
Author(s): Soo-Yoon Sung, Sung Hwan Kim, Joo Hwan Lee, Taek Keun Nam, Songmi Jeong, Hong Seok Jang, Jin Ho Song, Jeong Won Lee, Jung Min Bae, Jong Hoon Lee
PurposeResection margin status is a well-known prognostic factor after curative surgery in colorectal cancer. However, proper length and significance of circumferential resection margin (CRM) and distal resection margin (DRM) in rectal cancer patients who received neoadjuvant chemoradiotherapy (CRT) followed by total mesorectal excision (TME) has not been clearly determined yet.Methods and materialsA total of 1476 rectal cancer patients staging cT3-4N0-2M0 were analyzed. All patients received radiation dose of 50.4 Gy in 28 fractions with concurrent 5-fluorouracil or capecitabine. TME was performed 4 to 8 weeks after radiotherapy.ResultsThe recurrence-free survival (RFS) at 5 years showed a significant difference between three groups; patients with CRM ≤ 1mm, CRM 1.1-5mm, and CRM > 5mm (46.2% vs. 68.6% vs. 77.5%, P<0.001). Patients with CRM ≤ 1mm showed significantly higher cumulative incidence of locoregional (P<0.001) recurrence and distant (P<0.001) metastasis at 5 years compared to the other two groups. Patients with CRM 1.1-5mm showed a significantly higher cumulative incidence of distant metastasis (P<0.001), not locoregional recurrence (P=0.192) than those with CRM > 5mm. DRM (≤ 5 vs. > 5mm) did not show any significant difference in cumulative incidence of locoregional recurrence (P=0.310) and distant metastasis (P=0.926).ConclusionThe rectal cancer patients with CRM ≤ 1mm is a high-risk group with the lowest RFS. Patients with CRM 1.1-5mm may be at intermediate risk with moderately increased distant recurrence. DRM was not significantly associated with the RFS in rectal cancer after neoadjuvant CRT and TME.

Teaser

When the association between resection margin and recurrence-free survival (RFS) is assessed in rectal cancer patients who have received neoadjuvant chemoradiotherapy and curative surgery, patients with circumferential resection margin (CRM) ≤ 1mm, 1.1-5mm, and > 5mm showed an increasing RFS rate in order with a significant difference (P<0.001). However, distal resection margin was not a significant prognostic factor for the RFS in rectal cancer.


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