Risk factor analysis for inaccurate pre-operative MRI staging in rectal cancer

Zerong Cai,Yufeng Chen,Wuteng Cao,Yifeng Zou,Xiaojian Wu,Zexian Chen,Ping Lan,Khamis Salem Saeed Saad,Xiaoyu Xie

doi:10.1186/s12885-020-06761-0

Abstract

BackgroundVarious tumor characteristics might lead to inaccurate local MRI-defined stage of rectal cancer and the purpose of this study was to explore the clinicopathological factors that impact on the precision pre-treatment MRI-defined stage of rectal cancer.MethodsA retrospectively analysis was conducted in non-metastatic rectal cancer patients who received radical tumor resection without neoadjuvant treatment during 2007–2015 in the Sixth Affiliated Hospital of Sun Yat-sen University. Clinical T stage and N stage defined by pelvic enhanced MRI and pathological stage were compared and patients were subdivided into accurate-staging, over-staging and under-staging subgroups. Logistic regressions were used to explore risk factors for over-staging or under-staging.ResultsFive hundred fifty-one cases of patients were collected. Among them, 109 cases (19.4%) of patients were over-T-staged and 50 cases (8.9%) were under-T-staged, while 78 cases (13.9%) were over-N-staged and 75 cases (13.3%) were under-N-staged. Logistic regression suggested that pre-operative bowel obstruction was risk factor for over-T-staging (OR = 3.120, 95%CI: 1.662–5.857, P < 0.001) as well as over-N-staging (OR = 3.494, 95%CI: 1.797–6.794, P < 0.001), while mucinous adenocarcinoma was a risk factor for under-N-staging (OR = 4.049, 95%CI: 1.876–8.772, P < 0.001). Patients with larger tumor size were at lower risk for over-T-staging (OR = 0.837, 95%CI: 0.717–0.976, P = 0.024) and higher risk for over-N-staging (OR = 1.434, 95%CI: 1.223–1.680, P < 0.001).ConclusionBowel obstruction, mucinous adenocarcinoma and tumor size might have impact on the pre-operative MRI T staging or N staging of rectal cancer. Our results reminded clinicians to assess clinical stage individually in such rectal cancer patients.

Highlights

Various tumor characteristics might lead to inaccurate local Magnetic resonance imaging (MRI)-defined stage of rectal cancer and the purpose of this study was to explore the clinicopathological factors that impact on the precision pre-treatment MRI-defined stage of rectal cancer
Treatment methods including pre-operative chemotherapy plus or not plus radiotherapy and total mesorectal excision plus radical tumor resection depends on the initial clinical stage in rectal cancer especially in those with tumor that extend beyond the rectal wall or lymph node metastatic disease [2]
Patients’ characteristics and MRI assessment Patients’ clinicopathological characteristics including gender, age, Body mass index (BMI), history of diabetes mellitus, pre-treatment serum Carcinoembryonic antigen (CEA) and CA199 level, present of bowel obstruction, pre-treatment white blood cell (WBC), hemoglobin (HB) and plate (PLT) level, tumor size of lesion according to the MRIs, location of tumor and pathological information were collected from the database of the Sixth Affiliated Hospital of Sun Yat-sen University

Summary

Introduction

Various tumor characteristics might lead to inaccurate local MRI-defined stage of rectal cancer and the purpose of this study was to explore the clinicopathological factors that impact on the precision pre-treatment MRI-defined stage of rectal cancer. Treatment methods including pre-operative chemotherapy plus or not plus radiotherapy and total mesorectal excision plus radical tumor resection depends on the initial clinical stage in rectal cancer especially in those with tumor that extend beyond the rectal wall or lymph node metastatic disease [2]. Magnetic resonance imaging (MRI) has a high resolution of soft tissue and spatial resolution These properties of MRI make it suitable to assess involvement of rectal tumor into the circumferential resection margin, relationship of the tumor to the anal sphincter and any suspicious metastatic lymph node [4]. There was few article investigating factors that associated with over-staging or under-staging in the assessment of local stage by MRI, while tumor parameters such as tumor size, bowel obstruction, pathological subtype may influence the tumor morphology and tumor infiltration into the mesorectal lymph node

Objectives

Methods

Results

Discussion

Conclusion