Analysis of risk factors of lymph node metastasis and clinical significance of deep submucosal invasion in 64 cases of T1 stage colorectal cancer / 中华消化杂志

ABSTRACT

Objective:To investigate the risk factors of lymph node metastasis and the clinical significance of deep submucosal invasion in patients with T1 stage colorectal cancer.Methods:From January 30, 2010 to December 31, 2019, at Shandong Provincial Hospital Affiliated to Shandong First Medical University, among patients with T1 stage colorectal cancer, 41 patients underwent radical surgery for colorectal cancer (surgery group) and 23 patients received endoscopic submucosal dissection (ESD) (ESD group) were enrolled. The tumor gross type, maximum diameter, histologically poorly differentiated components, degree of invasion (the type of mucosal muscle destruction, the width and depth of invasion), the budding grade of tumor, and whether with vascular tumor thrombus were recorded. The additional treatment and prognosis of patients were collected by telephone follow-up. The risk factors of lymph node metastasis in stage T1 colorectal cancer, the correlation between the complete muscularis mucosa destruction and the width and depth of invasion in the ESD group, and the effects of additional treatment after operation on the prognosis of patients were analyzed. Independent sample t test and chi-square test were used for statistical analysis. Results:The rate of lymph node metastasis in patients with poorly differentiated components or vascular tumor thrombus was higher than that in patients without poorly differentiated components or vascular tumor thrombus (3/6 vs. 12.1%, 7/58; 3/4 vs. 11.7%, 7/60), and the differences were statistically significant ( χ2=5.934 and 11.409, both P<0.05). All patients in the surgery group had complete muscularis mucosa destruction. In ESD group, the width of tumor invasion was ≥ 2 mm in 16 cases, including complete destruction of muscularis mucosa in 15 cases and partial destruction in one case; the width of tumor invasion was <2 mm in seven cases, including complete destruction of muscularis mucoa in two cases and partial destruction in five cases; the depth of infiltration was ≥ 2 000 μm in 14 cases, including complete destruction of muscularis mucosa in 13 cases and partial destruction in one case; the depth of infiltration was <2 000 μm in nine cases, including complete destruction of muscularis mucosa in four cases and partial destruction in five cases. The complete muscularis mucosa destruction was related with tumor of invasion width ≥ 2 mm and invasion depth ≥ 2 000 μm (15/16 vs.2/7, 13/14 vs. 4/7), and the differences were statistically significant ( χ2=10.729, 6.659, both P<0.05). Among the 64 patients with T1 stage colorectal cancer in this study, six cases (9.4%) had poor prognosis; five cases (7.8%) died, and three of them (4.7%) were tumor-related deaths. Adjuvant therapy was added in 10 cases in surgery group and 10 cases in ESD group, and there were no poor prognosis in those patients. There were no significant difference in the incidences of poor prognosis of patients without additional treatment and patients with additional treatment of the two groups (9.7% (3/31) vs. 0 (0/10) and 23.1% (3/13) vs. 0 (0/10)) (both P>0.05). Conclusion:When T1 stage colorectal cancer with tumor submucosal invasion, clinicians should comprehensively evaluate the prognostic risk based on various pathological characteristics such as the degree of tumor differentiation, vascular tumor thrombus and mucosal muscle destruction.