Undifferentiated-predominant mixed-type early gastric cancer is more aggressive than pure undifferentiated type: a systematic review and meta-analysis

Abstract

BackgroundStudies have shown that differentiated-predominant mixed-type early gastric cancer (EGC) is more aggressive than pure differentiated-type EGC. However, the biological behaviour of undifferentiated-predominant mixed-type (MU) EGC and pure undifferentiated-type (PU) EGC are controversial. This study was conducted to compare the biological behaviour of MU EGC and PU EGC.MethodsA systematic review and meta-analysis of observational studies was conducted using literature published through PubMed and Embase from inception to 9 November 2021. Inclusion criteria were: (1) a direct or indirect comparison of MU and PU; (2) patients with EGC; (3) a specified outcome of lymph node metastasis (LNM), lymphovascular invasion, submucosal invasion and/or ulcer findings; and (4) the primary lesion was obtained. The literature search, data extraction and quality assessment were performed by two independent reviewers. The meta-analysis was conducted with a random-effect model using the Mantel-Haenszel method.ResultsTwelve publications with 5644 patients were included. Patients with MU EGC had significantly higher risk of LNM (OR 2.28; 95% CI 1.72 to 3.03) and submucosal invasion (OR 2.19; 95% CI 1.90 to 2.52) compared with patients with PU EGC. No difference was found between patients with MU and PU EGC with respect to lymphovascular invasion risk (OR 1.81; 95% CI 0.84 to 3.87). After stratifying the data according to depth of tumour invasion, a significantly higher risk for LNM was associated with intramucosal MU EGC (OR 2.56; 95% CI 1.66 to 3.95) and submucosal MU EGC (OR 2.63; 95% CI 2.06 to 3.06). Submucosal MU EGC also had a significantly higher risk of lymphovascular invasion (OR 2.40; 95% CI 1.79 to 3.21) compared with submucosal PU EGC.DiscussionPatients with MU EGC had an increased risk of submucosal invasion and LNM compared with patients with PU EGC . MU patients with submucosal EGC also had an increased lymphovascular invasion risk compared with PU patients. Therefore, attention should be focused on the clinical management of patients with MU EGC.

Value of enhanced computed tomography in differentiating small mesenchymal tumours of the gastrointestinal from smooth muscle tumours

“…The treatment methods for GIMTs have been rapidly changing with the development of medical treatment technology in recent years, and there are various methods commonly used for differential diagnosis in clinical practice[ 29 - 35 ]. However, the sensitivity of single tumour markers is low, and there is a certain degree of underdiagnosis; thus, combined detection of tumour markers is necessary for the diagnosis of GIMTs[ 36 ].…”

Endoscopic Resection of Early Gastric Cancer and Pre-Malignant Gastric Lesions

“…Additional risk factors identified in individual studies include large tumor size (generally >20 mm), ulceration, undifferentiated tumors (including the presence of an undifferentiated component in differentiated-type-predominant mixed-type lesions), and old age [ 26 , 27 , 28 , 29 , 30 , 31 ]. Regarding lesion differentiation, a meta-analysis incorporating 5644 patients showed that undifferentiated-predominant mixed-type lesions show more aggressive biological behavior compared to pure undifferentiated-type lesions, presenting a significantly higher risk of submucosal invasion (OR 2.19, 95%CI 1.90–2.52) and LNM (OR 2.28, 95%CI 1.72–3.03) even after stratification for depth of tumor invasion [ 32 ].…”

Endoscopic Resection of Undifferentiated Early Gastric Cancer

“…Mixed-type EGC is commonly identified during a review of ER specimens rather than in biopsies before ER [ 68 ]. There is some debate regarding the handling of mixed-type EGC, as mixed-type is known to be associated with more aggressive biological behavior than the non-mixed type [ 69 70 71 72 ]. In a recent systematic review and meta-analysis, patients with UD-predominant mixed EGC were found to have a significantly higher risk of submucosal invasion and LNM than those with pure UD-EGC [ 70 ].…”

“…There is some debate regarding the handling of mixed-type EGC, as mixed-type is known to be associated with more aggressive biological behavior than the non-mixed type [ 69 70 71 72 ]. In a recent systematic review and meta-analysis, patients with UD-predominant mixed EGC were found to have a significantly higher risk of submucosal invasion and LNM than those with pure UD-EGC [ 70 ]. Table 3 summarizes the frequency of LNM in the surgical specimens of EGC for UD-predominant mixed EGC and pure UD-EGC.…”