VS System for diagnosing early gastric cancer

### **VS Classification System for Diagnosing Early Gastric Cancer**

The **VS Classification System** is a standardized diagnostic approach designed to detect **early gastric cancer (EGC)** using **Narrow Band Imaging (NBI)**, a specialized endoscopic imaging technology. This system enhances the visualization of mucosal and vascular changes in the stomach lining, enabling precise and early detection of cancerous lesions.

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### **Key Components of the VS Classification System**

The VS system is based on the evaluation of two critical features:

1. **Vascular Pattern (V)**

2. **Surface Pattern (S)**

These features are assessed using **magnifying endoscopy with NBI**, which provides high-resolution images of the stomach's mucosal and submucosal layers.

#### **1. Vascular Pattern (V)**

• **Irregular Microvascular Architecture**:
• Distorted, tortuous, or dilated capillary structures.
• Loss of normal vascular symmetry and organization.
• **Demarcation Line**:
• A clear boundary separating abnormal vascular patterns from surrounding normal mucosa.
• **Corkscrew Vessels**:
• Abnormal, twisted vessels often seen in early gastric cancer, indicative of neoplastic changes.

#### **2. Surface Pattern (S)**

• **Irregular Microsurface Structure**:
• Loss of normal pit patterns.
• Presence of irregular, ridged, or nodular mucosal surface architecture.
• **White Zone Changes**:
• Areas of abnormal light reflection, suggesting mucosal damage or cancerous transformation.

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### **Diagnostic Criteria**

Early gastric cancer (EGC) is suspected when:

1. **Vascular Pattern**:

• Irregular microvascular architecture is observed.
• A distinct **demarcation line** separates the lesion from normal mucosa.

2. **Surface Pattern**:

• Irregular microsurface structure is present.
• **White zone changes** are visible.

When **both vascular and surface irregularities** are identified, the likelihood of EGC is significantly increased.

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### **Clinical Applications**

1. **Targeted Biopsy**:

• The VS system helps identify suspicious areas for biopsy, improving diagnostic accuracy and reducing unnecessary biopsies.

2. **Endoscopic Submucosal Dissection (ESD)**:

• Lesions diagnosed using the VS system can be resected precisely via ESD, ensuring complete removal with clear margins.

3. **Surveillance**:

• High-risk patients (e.g., those with chronic atrophic gastritis or intestinal metaplasia) can be monitored using the VS system to detect EGC at an early stage.

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### **Advantages of the VS Classification System**

1. **High Sensitivity and Specificity**:

• Improves diagnostic accuracy compared to conventional white light endoscopy (WLE).
• Sensitivity: ~88%; Specificity: ~75% (depending on study and operator expertise).

2. **Non-Invasive**:

• NBI is integrated into standard endoscopy systems, eliminating the need for dyes or additional equipment.

3. **Improved Diagnostic Yield**:

• Enhances the detection of subtle mucosal changes indicative of early gastric cancer.

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### **Limitations**

1. **Operator Dependence**:

• Requires expertise in magnifying NBI and familiarity with VS classification patterns.

2. **False Positives**:

• Inflammatory lesions or benign changes may mimic irregular vascular and surface patterns, leading to potential overdiagnosis.

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### **Comparison: VS Classification vs White Light Endoscopy (WLE)**

| **Parameter** | **VS Classification (NBI)** | **White Light Endoscopy (WLE)** |

|------------------------------|--------------------------------------|-----------------------------------------|

| **Vascular Visualization** | Enhanced with high contrast | Limited visualization |

| **Surface Architecture** | Detailed microsurface pattern | Poor resolution of surface patterns |

| **Diagnostic Accuracy** | Higher sensitivity and specificity | Lower sensitivity for early lesions |

| **Targeted Biopsy** | Precise biopsy sampling | Random biopsy sampling |

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### **Clinical Evidence Supporting VS Classification**

1. **Ezoe et al. (2011)**:

• Demonstrated that magnifying NBI with the VS system was more accurate than WLE for diagnosing gastric mucosal cancer.
• Sensitivity: 88%; Specificity: 75%.

2. **Zhang et al. (2016)**:

• A meta-analysis showed that NBI combined with the VS classification significantly improved diagnostic efficacy for EGC.

3. **Dinis-Ribeiro et al. (2017)**:

• Prospective studies confirmed that the VS system reduces unnecessary biopsies while maintaining high diagnostic accuracy.

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### **Future Directions**

1. **Artificial Intelligence (AI)**:

• AI algorithms are being developed to automate the VS classification process, reducing operator dependency and enhancing diagnostic precision.

2. **Training Programs**:

• Structured training for endoscopists to improve proficiency in recognizing VS patterns and using NBI technology.

3. **Expansion to Other GI Cancers**:

• The VS classification system may be adapted for diagnosing other gastrointestinal cancers, such as esophageal or colorectal neoplasms.

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### **Summary**

The **VS Classification System** is a powerful tool for diagnosing **early gastric cancer (EGC)** using **Narrow Band Imaging (NBI)**. By evaluating **vascular patterns** (irregular microvascular architecture, demarcation line) and **surface patterns** (irregular microsurface structure, white zone changes), the system provides high sensitivity and specificity for early cancer detection. It facilitates **targeted biopsies**, improves diagnostic accuracy, and supports precise therapeutic interventions like **endoscopic submucosal dissection (ESD)**. Despite its operator dependency, the VS system represents a significant advancement in endoscopic imaging, offering the potential for earlier detection and better outcomes in gastric cancer management.