Published online Dec 28, 2017. doi: 10.3748/wjg.v23.i48.8582
Peer-review started: July 21, 2017
First decision: August 30, 2017
Revised: October 21, 2017
Accepted: November 28, 2017
Article in press: November 28, 2017
Published online: December 28, 2017
Lymph node metastasis is the primary type of metastasis seen in advanced colorectal cancer (CRC). The occurrence rate of T1-stage CRC has been reported to be approximately 3.51%[5,6]. When the tumor is completely removed, patients with T1-stage CRC generally have a good prognosis. However, since lymph node metastasis rarely occurs in T1-stage CRC, lymph node metastasis is often overlooked during the process of diagnosis and treatment. Nevertheless, lymph node metastasis is one of the most essential prognostic factors. In this study, we explored the features and prognostic value of lymph node metastasis, which will provide a theoretical basis for more effective treatment of patients with T1-stage CRC.
The main topic of this study is the exploration of whether lymph node metastasis in patients with T1-stage CRC is valuable for patient survival in multiple centers in China. The key is to find the risk factors for lymph node metastasis of CRC. The significance is the confirmation of the prognostic value of lymph node metastasis in patients with T1-stage CRC.
Studies have reported that lymph node metastasis is an essential prognostic factor for patients with CRC and that lymph node metastasis seldom occurs in T1-stage CRC. However, the definitive prognostic value of lymph node metastasis of T1-stage CRC remains elusive. The main objective of this study was to explore the features and prognostic value of lymph node metastasis in patients with T1-stage CRC.
The current research was a case-control study.
The occurrence rate of T1 stage CRC was 3.17% (321/10,132); of these cases, the lymph node metastasis rate was 8.41% (27/321), and the non-lymph node metastasis rate was 91.59% (294/321). Univariate analysis showed that preoperative serum CEA, preoperative serum CA199, preoperative serum CA724, vascular invasion, and degree of differentiation were associated with lymph node metastasis in T1-stage CRC. Multivariate analysis indicated that preoperative serum CA724, vascular invasion, and degree of differentiation were closely related to lymph node metastasis. Log-rank survival analysis showed that age, preoperative serum CEA, preoperative serum CA199, vascular invasion, degree of differentiation, and lymph node metastasis were prognostic factors for 5-year OS. COX regression analysis demonstrated that preoperative serum CA199 and lymph node metastasis were independent prognostic factors for 5-year OS of patients with T1-stage CRC.
The morbidity of T1-stage CRC was 3.17% out of all cases of CRC. Preoperative serum CA724, vascular invasion, and degree of differentiation were independent risk factors for lymph node metastasis of T1-stage CRC. Lymph node metastasis was an independent prognostic factor of OS in patients with T1-stage CRC.
T1-stage CRC is generally regarded as the early stage, easily leading to the neglect of metastasis, especially lymph node metastasis. However, the prognosis of a little part of these cases (8.41%) with lymph node metastasis will be much poorer than those without. We also analysed high risk factors of lymph node metastasis of T1-stage CRC patients. Therefore, we must pay enough attention to lymph node metastasis status of T1-stage CRC patients to guide clinic therapy. Future studies should be focused on greater verifying study to expand further clinical samples. In addition, the mechanistic study of lymph node metastasis in T1-stage CRC patients should be further explored. Multi-center prospective cohort clinical studies will be needed to further validate the conclusion. Moreover, high-throughput transcriptome or proteome screening technology will be necessary for analysing the regulators of lymph node metastasis in T1-stage CRC patients in the future.