From the Guidelines
Staging of Gastric Cancer
The key points for staging gastric cancer from Stage 0 to Stage IV are based on the AJCC/UICC staging system, which considers the tumor size and extent (T), lymph node involvement (N), and presence of metastasis (M) 1.
- Stage 0 (Carcinoma in situ): The cancer is confined to the mucosa and has not invaded the basement membrane.
- Stage I: The cancer has invaded the submucosa (T1) and may have involvement of 1-2 regional lymph nodes (N1).
- Stage II: The cancer has invaded the muscularis propria (T2) or the subserosa (T3) and may have involvement of 3-6 regional lymph nodes (N2).
- Stage III: The cancer has invaded the serosa (T4a) or has spread to nearby organs (T4b) and may have involvement of 7 or more regional lymph nodes (N3).
- Stage IV: The cancer has spread to distant organs, such as the liver, lungs, or peritoneum (M1).
Key Considerations
When staging gastric cancer, it is essential to evaluate at least 16 lymph nodes to ensure accurate staging 1. The Lauren classification can also be used to classify gastric adenocarcinoma into intestinal, diffuse, or mixed types based on histological growth patterns 1.
Diagnostic Modalities
Various diagnostic modalities, such as endoscopic ultrasound (EUS), CT scanning, and FDG-PET, can be used to assess the depth of tumor invasion and nodal involvement 1. However, the accuracy of these modalities can vary, and a combination of modalities may be necessary for accurate staging.
Pathological Evaluation
The pathological evaluation of gastric cancer specimens should include meticulous resection, collection, and preparation of specimens, as well as evaluation of lymph node metastasis and carcinomatous nodules 1. The Borrmann classification can also be used to classify gastric cancer into four subtypes based on tumor morphology.
Treatment Implications
Accurate staging of gastric cancer is crucial for determining the optimal treatment strategy, which may include surgery, chemotherapy, radiation therapy, or a combination of these modalities 1.
From the Research
Staging of Gastric Cancer
The staging of gastric cancer is critical for determining the prognosis and survival prediction of patients. The American Joint Committee on Cancer (AJCC) staging system is the most widely applied system to determine the disease's prognosis and survival prediction 2. The staging system incorporates the depth of tumor invasion, extent of lymph node, and distant metastases.
Key Points for Staging Gastric Cancer
- Stage 0: Carcinoma in situ, where the cancer is limited to the mucosa and has not invaded the basement membrane 3
- Stage I: The cancer has invaded the submucosa, but has not extended beyond the gastric wall 3
- Stage II: The cancer has invaded the muscularis propria or the subserosa, but has not extended beyond the gastric wall 3
- Stage III: The cancer has extended beyond the gastric wall, but has not metastasized to distant sites 3
- Stage IV: The cancer has metastasized to distant sites, such as the liver, lungs, or peritoneum 3
Imaging Modalities for Staging Gastric Cancer
- Multidetector computed tomography (MDCT) is the preferred technique for staging gastric cancer, as it can assess tumor depth, nodal disease, and metastases 4
- Endoscopic ultrasonography is more accurate for assessing the depth of wall invasion in early cancer, but is limited in the assessment of advanced local or stenotic cancer and detection of distant metastases 4
- Positron emission tomography (PET) is most useful for detecting and characterizing distant metastases 4
Clinical and Pathological Staging
- Accurate categorization of invasive depth and lymph node metastasis is fundamentally critical for prognostic assessment and decision making regarding subsequent therapies after surgery for gastric cancer 3
- The quality of standardized pathological diagnosis of gastric cancer requires improvement, and a new development in TNM staging and a way to improve clinical and pathological quality control of gastric cancer is needed 3
Surgical Approaches
- Resection is the cornerstone of cure for gastric adenocarcinoma, and a D2 lymphadenectomy is preferred for curative-intent resection of gastric cancer 5
- At least 16 lymph nodes should be assessed for adequate staging of curative-resected gastric cancer 5
- Gastric cancer surgery should aim to achieve an R0 resection margin, and patients should be referred to higher-volume centers and those that have adequate support to manage potential complications 5