Endoscopy is a crucial diagnostic tool for detecting gastric cancer. During the characterization process, endoscopists follow the Yao classification, which involves examining the mucosal aspects, surface, vessels, and demarcation line. The demarcation line is an important feature that separates cancer from benign lesions. By applying dyes such as Indigo Carmine or Meylin blue, endoscopists can better define the lesion and look at the borders, surface pattern, and submucosal pattern.
In addition, systematic screening is essential for detecting gastric cancer. In Japan, 22 pictures are standard for doing screening of the stomach, and in some places, more than those pictures are taken. However, it is important to be thorough and methodical during endoscopy, as missing a cancer can have serious consequences. Time considerations are also crucial, as studies have shown that endoscopists who take longer to perform endoscopy have higher detection rates of neoplastic lesions. Biopsy rate is another important quality indicator, as endoscopists with high or very high biopsy rates are more likely to find cancers or miss fewer cancers.
Yao Classification Overview
In endoscopic characterization, the Yao classification is followed, which involves examining the surface, mucosal aspects, vessels, and demarcation line. The demarcation line is the area that distinguishes between cancer and benign lesions. It is important to note that the demarcation line can be clearly seen through histological proof.
To better define the lesion and examine the borders, demarcation line, surface pattern, and submucosal pattern, dyes such as Indigo Carmine, Meylin Blue, or Toluidine Blue can be applied. Narrow band imaging studies have not shown an increase in gastric cancer detection, so NBI is mainly used for characterization. However, relying on white light endoscopy and skills to detect mucosal changes, submucosal vessels, and the demarcation line is still important in areas without Zoom endoscopes.
The Japanese approach to systematic screening for the stomach involves taking 22 pictures, with some places taking more. However, this approach has some defects, such as diminished focus on areas, poor stomach inflation, and many folds present, increasing the chances of missing a cancer. A better approach involves good insulation of the stomach, smoother endoscope movements, and taking time to perform a thorough examination.
Studies have shown that endoscopists who take less than 5 minutes to perform an endoscopy have a detection rate of neoplastic lesions of only 0.57%, while those who take longer than 7 minutes have a detection rate of 0.94%. Therefore, performing an endoscopy of the upper GI tract for around 7 to 8 minutes is recommended.
An important quality indicator for endoscopists may be their biopsy rate. Studies have shown that endoscopists with high or very high biopsy rates are more prone to find cancers or miss fewer cancers than those with low or moderate biopsy rates.
Demarcation Line Definition
The demarcation line is an important area that serves as a border between a cancerous lesion and a benign one. It is a crucial aspect to consider when characterizing lesions. Endoscopists follow the Yao classification, which involves examining the surface, mucosal aspects, vessels, and demarcation line of the lesion. The demarcation line can be seen clearly in endoscopic images and can be proven histologically.
To better define the lesion and examine its borders, dyes such as Indigo Carmine, Meylin Blue, or Toluidine Blue can be applied. This allows for a more thorough examination of the surface and submucosal patterns, as well as the vessels and demarcation line.
Narrow Band Imaging (NBI) has been used to characterize lesions, but studies have not shown an increase in gastric cancer detection. Therefore, NBI is mainly used for characterization, and endoscopists rely on their skills and visual inspection to detect mucosal changes, submucosal vessels, and the demarcation line.
Systematic screening of the stomach is essential, and the Japanese approach of using 22 standard pictures for screening is a good example. However, some defects can be observed in this approach, such as a diminished focus on certain areas, poor stomach inflation, and the presence of folds that can increase the chances of missing a cancer.
To increase the detection rate of neoplastic lesions, endoscopists should take their time during the procedure. A study conducted in 2005 found that endoscopies that took less than five minutes had a detection rate of 0.57%, while those that took longer than seven minutes had a detection rate of 0.94%. Therefore, performing an endoscopy of the upper GI tract for around seven to eight minutes is recommended.
Moreover, the biopsy rate of the endoscopist is an essential quality indicator. Endoscopists who have high or very high biopsy rates are more prone to find cancers and miss fewer cancers than those with low or moderate biopsy rates.
Endoscopic Examination Techniques
Mucosal Inspection
During endoscopic examination, the mucosal surface of the gastrointestinal tract is carefully inspected. Using white light endoscopy and skills to detect mucosal changes, endoscopists can identify any abnormal areas that may require further investigation. In systematic screening for the stomach, 22 pictures are standard for doing screening of the stomach, and in some places more than those pictures are done. However, this systematic screening has some defects, such as the focus of the areas being diminished, the stomach not being well inflated, and the presence of many folds.
Submucosal Vessel Evaluation
In addition to mucosal inspection, endoscopists also evaluate the submucosal vessels. This is done to identify any abnormal blood vessels that may indicate the presence of a lesion. By applying dyes, such as Indigo Carmine or Meylin Blue, or Top in Blue, one can better define the lesion and look at the borders, the demarcation line, and also at the surface pattern and submucosal pattern. Interestingly, studies using narrow-band imaging have not shown the detection of gastric cancer increases. Therefore, nowadays, NBI is mainly used for characterization.
Dye Application in Lesion Definition
Dye application is an important tool for endoscopists in lesion definition. By applying dyes, such as Indigo Carmine or Meylin Blue, or Top in Blue, endoscopists can better define the lesion and look at the borders, the demarcation line, and also at the surface pattern and submucosal pattern. This technique is particularly useful in identifying the demarcation line, which is the area where there is a border between a cancer and a benign lesion. The demarcation line can be proven histologically, and it is important to identify it during endoscopic examination.
Importance of Systematic Screening
Japanese Screening Approach
The Japanese approach to systematic screening of the stomach involves taking a standard set of 22 pictures, with some places even taking more than that. This approach is considered excellent for systematic screening, allowing for thorough inspection of the mucosa and submucosal vessels. However, there are some defects in this approach, such as a diminished focus on certain areas of the stomach, inadequate inflation, and the presence of folds. These defects increase the chances of missing a cancer during endoscopy.
Screening Deficiencies and Improvements
Studies have shown that endoscopists are still missing gastric cancer, even in Japan where the systematic screening approach is widely used. To improve detection rates, endoscopists should take their time during the procedure, with a recommended duration of 7 to 8 minutes for upper GI tract endoscopy. A study from 2005 found that endoscopies lasting less than 5 minutes had a detection rate of neoplastic lesions of only 0.57%, compared to 0.94% for endoscopies lasting longer than 7 minutes.
Another important quality indicator for endoscopists is their biopsy rate. A study in Poland found that endoscopists with high or very high biopsy rates were more likely to find cancers and miss fewer cancers, compared to those with low or moderate biopsy rates. This highlights the importance of thorough and methodical screening, as well as the need for biopsies to be done routinely in countries where they are not currently standard practice.
In conclusion, systematic screening is crucial for detecting gastric cancer and other neoplastic lesions. The Japanese approach provides an excellent starting point, but improvements can be made to increase detection rates and reduce the risk of missing cancers. Endoscopists must take their time, be thorough, and incorporate biopsies into their screening protocol to ensure the best possible outcomes for their patients.
Time Considerations in Endoscopy
During endoscopy, it is essential to take the time to thoroughly examine the mucosa, submucosa, vessels, and demarcation line. The demarcation line is the area that separates a cancerous lesion from a benign one. To better define the lesion and examine the borders, applying dyes such as Indigo Carmine, Meylin Blue, or Toluidine Blue is useful.
Narrow Band Imaging (NBI) is mainly used for characterization, but studies have not shown an increase in the detection of gastric cancer. Therefore, relying on white light endoscopy and skills to detect mucosal changes, submucosal vessels, and demarcation lines is crucial.
In Japan, a systematic screening for the stomach is conducted using 22 standard pictures. However, some areas may be missed due to a lack of focus, poor inflation of the stomach, and folds present. It is recommended to take time and be thorough during endoscopy, as studies have shown that detection rates of neoplastic lesions increase when the procedure lasts longer than seven minutes.
Furthermore, a high or very high biopsy rate is a quality indicator for endoscopists. In Poland, endoscopists with high biopsy rates were found to miss fewer cancers compared to those with low or moderate biopsy rates. Therefore, performing biopsies routinely is recommended.
In summary, taking the time to thoroughly examine the mucosa, submucosa, vessels, and demarcation line during endoscopy is essential for accurate detection of neoplastic lesions. Additionally, performing biopsies routinely and taking time during the procedure can improve detection rates and reduce the chances of missing cancers.
Biopsy Rate as a Quality Indicator
An important quality indicator for endoscopists may be the biopsy rate. In a study conducted in Poland, 26 endoscopists in the National cancer screening program performed almost 30,000 endoscopies over 13 years. The study found that endoscopists with high or very high biopsy rates were more likely to find cancers or, more importantly, miss fewer cancers. Patients of endoscopists with low or moderate biopsy rates missed 29 cancers compared to only seven in the other group.
In addition to biopsy rates, thorough and methodical endoscopy is crucial for detecting mucosal changes, submucosal vessels, and the demarcation line between cancer and benign lesions. Endoscopists should use dyes such as Indigo Carmine or meylin blue to better define the lesion and look at the borders, demarcation line, surface pattern, and submucosal pattern. While narrow band imaging has not shown an increase in the detection of gastric cancer, it is still mainly used for characterization.
Systematic screening for the stomach, like the approach in Japan, is an excellent method for detecting gastric cancer. However, this method has some defects, such as diminished focus of areas, poor stomach inflation, and numerous faults present. Thorough and timely endoscopy is crucial, and endoscopists should take their time to ensure that the procedure lasts around 7 to 8 minutes. A study found that if the endoscopy takes less than 5 minutes, the detection rates of neoplastic lesions are only 0.57%, whereas if the endoscopy was longer than 7 minutes, it was 94%. Therefore, endoscopists should be systematic, timely, and thorough to detect gastric cancer.