Early gastric cancer and lymph node metastasis

Area of Science:

• Gastroenterology
• Oncology
• Surgical Pathology

Background:

• Gastric cancer resection is a common procedure, with early gastric cancer (EGC) representing a significant portion.
• Understanding metastasis patterns in EGC is crucial for treatment planning and patient outcomes.

Purpose of the Study:

• To analyze lymph node metastasis rates in early gastric cancer based on depth of invasion, macroscopic type, microscopic differentiation, and tumor size.
• To identify risk factors for lymph node metastasis in EGC.

Main Methods:

• Retrospective analysis of 1,845 gastric cancer resections over 18 years.
• Stratification of early gastric cancer cases by depth (mucosal vs. submucosal), macroscopic type, microscopic differentiation, and tumor size.
• Comparison of lymph node metastasis rates across different subgroups.

Main Results:

• Overall, 41.5% of resected gastric cancers were early gastric cancer.
• Lymph node metastasis rates were significantly higher in early submucosal cancer (19.4%) compared to early mucosal cancer (2%).
• Early mucosal cancer with lymph node metastasis was associated with specific macroscopic (0-IIc, IIc + III) and microscopic (poorly differentiated) types.
• Early submucosal cancers showed higher metastasis rates in mucinous (40%) and papillary (33%) adenocarcinomas.
• No lymph node metastasis was observed in EGC cases smaller than 1 cm in surface diameter.

Conclusions:

• Depth of invasion is a critical factor in lymph node metastasis for early gastric cancer.
• Tumor size < 1 cm is a favorable prognostic indicator, suggesting minimal metastatic potential.
• Accurate staging and risk stratification are essential for optimizing treatment strategies in early gastric cancer.