Acquisition of histologic diversity contributes to not only invasiveness but also lymph node metastasis in early gastric cancer

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.

Mixed Histologic Type is a Risk Factor for Lymph Node Metastasis in Submucosal Invasive Early Gastric Cancer

INTRODUCTION

The treatment regimen for early gastric cancer (EGC) with mixed histologic type remains controversial. We aimed to clarify the relationship between mixed histologic type and lymph node metastasis (LNM) in EGC, with emphasis on submucosal invasive EGC.

METHODS

We collected data on 730 consecutive EGC patients at Nanjing Drum Tower hospital between June 2010 and May 2019. Risk factors of LNM and overall survival were analyzed to compare the prognostic differences between different histologic types.

RESULTS

Mixed-type EGC patients had higher LNM rates than differentiated-type patients (29.2 % versus 10.6 %, P < 0.001), while no significant difference was found between mixed-type and undifferentiated-type EGC patients (29.2% versus 24.0%, P = 0.225). Multivariate analyses identified tumor location (cardiac and bottom versus antrum), larger tumor size, submucosal invasion, histologic differentiation (undifferentiated-type, mixed-type versus differentiated-type), and lymphovascular invasion as independent risk factors for LNM in EGC patients. Subgroup analysis further elucidated that mixed histologic type was associated with LNM in submucosa invasive EGC, but not in mucosa-confined EGC. There was no statistical significance in overall survival and disease-specific survival of submucosal invasive EGC patients who underwent radical gastrectomy with lymphadenectomy between different histologic types (P = 0.151).

CONCLUSIONS

Mixed histologic type may be an independent risk factor for LNM in submucosal invasive EGC. Curative resection with lymphadenectomy should be considered the appropriate treatment for submucosal invasive EGC with mixed histologic type.

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.

Histological diversity and molecular characteristics in gastric cancer: relation of cancer stem cell-related molecules and receptor tyrosine kinase molecules to mixed histological type and more histological patterns

BACKGROUND

Gastric cancers (GCs) are still one of the leading causes of cancer-related mortality. The histological and molecular features of GC may differ widely from area to area within the same tumor. Intratumoral heterogeneity has been considered a major obstacle to an efficient diagnosis and successful molecular treatment.

METHODS

We selected and reevaluated 842 GC cases and analyzed the relationship between numbers or composites of histological patterns within tumors, and clinicopathological parameters in mucosal and invasive areas. In addition, we searched for the GC-associated molecules or molecular subtypes marking histological diversities.

RESULTS

GC cases with more histological numbers or mixed types in invasive areas showed significantly higher T grade and staging, whereas those in mucosal areas did not show any significant associations. GCs with histological diversities showed poorer prognosis and characteristically expressed cancer stem cell-related molecules (CD44, CD133 or ALDH1) and receptor tyrosine kinase molecules (HER2, EGFR or c-MET) as well as Helicobacter pylori infection. Expressions of CD44, HER2, c-MET, laminin 5·2 or retained E-cadherin in mucosal areas were predictive of more histological numbers and mixed types in invasive areas. In addition, the chromosomal instability subtype of GC showed significant associations with more histological numbers and mixed histological type, whereas the genomic stability subtype of GC showed a significant relationship with pure type.

CONCLUSIONS

We displayed the relationship between histological diversity and molecular features in GC, and we hope that the present data can contribute to the early diagnosis and prevention, and effective treatment of GC.

Identification and external validation of a novel miRNA signature for lymph node metastasis prediction in submucosal-invasive gastric cancer patients

Endoscopic resection (ER) has been increasingly performed in the treatment of early gastric cancer (GC). However, lymph node metastasis (LNM) can cause treatment failure with ER, especially in T1b patients. Here, we attempted to develop a miRNA‐based classifier to detect LNM in T1b patients. Based on high‐throughput data from The Cancer Genome Atlas, we identified 20 miRNAs whose expression significantly changed in T1‐2 GC with LNM vs T1‐2 GC without LNM. We then developed a miRNA signature to predict LNM of T1b GC using the LASSO model and backward step wise elimination approach in a training cohort. Furthermore, the predictive accuracy of this classifier was validated in both an internal testing group of 63 patients and an external independent group of 114 patients. This systematic and comprehensive in silico study identified a 7‐miRNA signature with an area under the receiver operating characteristic curve (AUROC) value of 0.843 in T1‐2 GC and 0.911 in T1 EGC. The backward elimination was further used to develop a 4‐miRNA (miR‐153‐3p, miR‐708, miR‐940 and miR‐375) risk‐stratification model in the training cohort with an AUROC value of 0.898 in cohort 2. When pathologic results were used as a reference, the risk model yielded AUROC values of 0.829 and 0.792 in two cohorts of endoscopic biopsy specimens. This novel miRNA‐LNM classifier works better than the currently used pathologic criteria of ER in T1b EGC. This classifier could individualize the management of T1b patients and facilitate treatment decisions.