Extracapsular Extension Does Not Decrease Overall Survival in Rectal Cancer Patients with Lymph Node Metastasis Following Neoadjuvant Chemoradiotherapy

Background. The Tumor-Node-Metastasis system does not include additional prognostic factors present in the Lymph Node Metastasis (LNM) such as extra-capsular extension (ECE), which is associated with decreased survival. There are not studies addressing this topic in rectal cancer patients with preoperative chemoradiotherapy (nCRT) and total mesorectal excision (TME). Aim. We aimed to examine the survival influence of ECE in patients with stage III rectal cancer who received nCRT followed by surgery. Methods. A retrospective study of 126 patients prospectively collected with rectal cancer in clinical stage III rated with nCRT and TME from 2010 to 2015 was performed. Results. In total, 71.6% of cases had 1 to 3 lymph node metastases, most tumors were grade 2 (52.4%), 25.4% had good pathologic response, 77.8% had a good quality TME, and the median tumor budding count was 4/0.785 mm(2). Forty-four (34.9%) patients had ECE+, which was associated with a higher nodal stage (pN2), perineural invasion and a higher lymph node retrieval. The factors associated with the survival were a higher pathologic T stage, higher pathological N stage, high-grade tumors, and perineural invasion. The ECE did not decrease the 5-year survival with a similar median survival (86.5 months for the ECE+ group vs. 84.1 for the ECE-). Conclusion. Our results demonstrate that ECE has no impact on overall survival in rectal cancer patients who received nCRT and this was independent of nodal stage or number of lymph nodes examined.