Histopathological validation of magnifying endoscopy for diagnosis of mixed-histological-type early gastric cancer

Endoscopic Submucosal Dissection Criteria for Differentiated-type Early Gastric Cancer Are Applicable to Mixed-type Differentiated Predominant

BACKGROUND

There is a lack of sufficient evidence on whether mixed-type differentiated predominant early gastric cancer (MD-EGC) can be treated endoscopically by referring to the criteria for differentiated-type early gastric cancer (EGC). This study aims to evaluate the efficacy of endoscopic submucosal dissection (ESD) in MD-EGC.

METHODS

Patients with differentiated-type EGC treated with ESD first from January 2015 to June 2021 were reviewed, including MD-EGC and pure differentiated-type EGC (PD-EGC). Clinical data, including the clinicopathological characteristics, resection outcomes of ESD, and recurrence and survival time, were collected, and the difference between MD-EGC and PD-EGC was tested.

RESULTS

A total of 48 patients (48 lesions) with MD-EGC and 850 patients (890 lesions) with PD-EGC were included. Compared with PD-EGC, MD-EGC had a higher submucosal invasion rate (37.5% vs. 13.7%, P<0.001) and lymphatic invasion rate (10.4% vs. 0.4%, P<0.001). The rates of complete resection (70.8% vs. 92.5%, P<0.001) and curative resection (54.2% vs. 87.4%, P<0.001) in MD-EGC were lower than those of PD-EGC. Multivariate analysis revealed that MD-EGC (OR 4.26, 95% CI, 2.22-8.17, P<0.001) was an independent risk factor for noncurative resection. However, when curative resection was achieved, there was no significant difference in the rates of recurrence (P=0.424) between the 2 groups, whether local or metachronous recurrence. Similarly, the rates of survival(P=0.168) were no significant difference.

CONCLUSIONS

Despite the greater malignancy and lower endoscopic curative resection rate of MD-EGC, patients who met curative resection had a favorable long-term prognosis.

Risk factors of additional surgery after non-curative endoscopic submucosal dissection for early gastric cancer

BACKGROUND

The criteria for surgical intervention after non-curative endoscopic submucosal dissection (ESD) of early gastric cancer are unclear. We aimed to clarify the risk factors for residual cancer and lymph node metastasis after non-curative ESD and to identify recommendations for additional surgery.

METHODS

We collected data on 133 consecutive patients who underwent additional surgery after non-curative ESD of early gastric cancer at Nanjing Drum Tower Hospital from January 2013 to July 2022. Univariate and multivariate analyses were performed to seek risk factors of residual cancer and lymph node metastasis.

RESULTS

The incidence rates of residual cancer and lymph node metastasis were 13.5% (18/133) and 10.5% (14/133), respectively. There was neither residual tumor nor lymph node metastasis in 104 (78.2%) cases. Multivariate analyses elucidated that horizontal margin was an independent risk factor for local residual cancer, whereas lymphatic infiltration was an independent risk factor for lymph node metastasis. Patients with mixed histological types were more likely to suffer lymph node metastasis and further undergo additional surgery after non-curative ESD than pure histological type.

CONCLUSIONS

Additional gastrectomy with lymph node dissection was strongly recommended in patients with lymphatic infiltration after non-curative ESD of early gastric cancer. Patients with mixed histological type have a high propensity for lymph node metastasis and should be treated as a separate subtype.

Relationship between histological mixed-type early gastric cancer and lymph node metastasis: A systematic review and meta-analysis

The clinicopathological features of early gastric cancer (EGC) with mixed-type histology (differentiated and undifferentiated) are incompletely understood, and the capacity of endoscopic submucosal dissection (ESD) to treat mixed-type cancer remains controversial. This systematic review analyzed the rate of lymph node metastasis (LNM) in mixed-type EGC. We gathered articles published up to February 21, 2021, that analyzed the relationship between LNM and mixed-type EGC from Embase, PubMed, and Web of Science. The primary outcome was the LNM rate associated with different histological types of EGC, and the secondary outcomes were the odds ratios (ORs) for LNM risk factors among EGC patients. From the 24 studies included in this meta-analysis, the overall rate of LNM in predominantly differentiated mixed-type (MD) EGC was 12%, whereas the LNM rate in predominantly undifferentiated mixed-type (MU) EGC was 22%. We further divided these studies into 2 groups according to the depth of invasion. In mixed-type mucosal EGC, the pooled LNM rate was 15%; in submucosal EGC, the rate was 33% for MU, which was higher than the rates for pure types (pure differentiated type, 13%; pure undifferentiated type, 21%; p<0.05). The LNM rate of MD was 20%, it was higher than those of the pure differentiated type and nearly the same as pure undifferentiated type. Other pooled statistics showed that submucosal invasion, pure undifferentiated EGC, and mixed-type EGC were independent risk factors for LNM. This meta-analysis showed that MD submucosal EGC has a high rate of LNM and is highly correlated with LNM; thus, the management of MD EGC as purely differentiated EGC according to the indications for ESD is inappropriate, and the mixed type should be added as a parameter in these indications.