Gastric Cancer: Early Diagnosis, Risk Factors, and Gastroscopy

Introduction: Why is early diagnosis of gastric cancer critical?

Gastric cancer remains one of the leading causes of cancer-related mortality worldwide. Despite significant progress in understanding its pathophysiology and risk factors, the disease is often diagnosed at advanced stages, leading to poor outcomes [5]. Late detection of gastric cancer is a major public health challenge, highlighting the urgent need for effective strategies for early diagnosis and prevention.

Global disparities in the incidence, mortality, and stage at diagnosis of gastric cancer remain significant [5]. This indicates unequal access to screening programs and quality medical care. Understanding key risk factors and utilizing modern diagnostic methods, such as gastroscopy, can significantly improve patient prognosis.

Main risk factors for developing gastric cancer

The development of gastric cancer is a complex, multi-step process often associated with chronic inflammation and precancerous changes. Identifying and managing these risk factors is crucial for prevention and early diagnosis.

Helicobacter pylori infection

The bacterium Helicobacter pylori (H. pylori) is a well-studied and established gastric carcinogen [7]. Chronic H. pylori infection leads to prolonged inflammation of the gastric mucosa, which can trigger a cascade of precancerous changes.

Precancerous conditions and the Correa cascade

Many cases of gastric cancer develop from a sequence of precancerous lesions known as the Correa cascade. This process includes:

• Chronic atrophic gastritis (CAG): This is a key precancerous lesion characterized by the loss of glandular cells in the gastric mucosa [2, 8].
• Intestinal metaplasia (IM): The replacement of normal gastric epithelium with intestinal epithelium [3, 8].
• Dysplasia: Abnormal cell growth, which is a direct precursor to cancer [8].

Research has shown that precancerous lesions such as atrophic gastritis, intestinal metaplasia, and dysplasia were present in 35.6% of gastric resection specimens in patients with gastric adenocarcinoma [8]. This underscores the importance of their timely detection.

Modifiable lifestyle factors

A number of lifestyle factors significantly increase the risk of developing chronic atrophic gastritis, and consequently, gastric cancer:

• Smoking: Active smoking is a known risk factor [2].
• Alcohol consumption: Excessive alcohol consumption is also associated with an increased risk [2].
• Dietary habits: Certain dietary habits, such as frequent consumption of fried foods, can influence risk. In one study conducted among 21,008 Chinese adults, simple risk assessment scales for CAG were developed and validated, including seven modifiable lifestyle factors, such as the consumption of fried foods and garlic (as exploratory components) [2].

Understanding these modifiable factors allows for the development of prevention and screening strategies aimed at changing lifestyle and reducing overall risk.

The role of gastroscopy in the early diagnosis of gastric cancer

Endoscopy, or gastroscopy, is the gold standard for the early detection of gastric cancer and precancerous conditions. Advances in endoscopic technology have significantly improved the potential for early diagnosis [5].

What is looked for during gastroscopy?

An experienced endoscopist can identify subtle changes in the mucosa that indicate precancerous conditions or early cancer. Such signs include:

• Signs of atrophic gastritis and intestinal metaplasia: These changes may appear as areas of pallor, thinning of the mucosa, or changes in its texture [3].
• Disappearance of the regular arrangement of collecting venules (RAC): This is an important endoscopic sign indicating mucosal atrophy [3].
• Features of gastritis: The morphology of gastritis is also significant.

Special attention is paid to patients who have undergone distal gastrectomy, who are at an increased risk of developing remnant gastric cancer (RGC). In such patients, the endoscopist evaluates the state of the anastomosis and the surrounding mucosa for signs such as redness, red streaks, enlarged folds, and bile reflux [3]. The presence of these signs, as well as atrophic gastritis and intestinal metaplasia, has been associated with an increased risk of RGC [3].

Challenges and innovations

Despite progress, there are still differences in approaches to endoscopic diagnosis in clinical practice [5]. One challenge is the so-called "interval gastric cancer" — cases where cancer develops or is discovered between scheduled endoscopic examinations, which may be related to both missed lesions and rapid progression [5]. Modern innovations, such as high-resolution endoscopy, narrow-band imaging (NBI), and other image-enhancement methods, help improve the visualization and detection of early neoplasia.

Management of gastric precancerous conditions

Active management of precancerous conditions, such as chronic atrophic gastritis, is an important strategy in preventing the development of gastric cancer. Treatment of these conditions can slow or stop the progression to more serious lesions.

For example, in one study on chronic atrophic gastritis, it was shown that combination therapy, including "rapid fire" needling and Xiaoliu Jin Jianwei decoction, significantly improved gastrointestinal symptoms and histopathological changes in the gastric mucosa. Patients receiving the combined treatment showed a reduction in symptom scores (GSRS), histopathological indices, and levels of inflammatory markers (high-sensitivity C-reactive protein and tumor necrosis factor-α), as well as higher overall efficacy (93.40% vs. 71.60% in the control group) [1]. This demonstrates the potential of comprehensive approaches in managing precancerous conditions.

Regular endoscopic monitoring of patients with diagnosed precancerous changes, such as atrophy or intestinal metaplasia, allows for the timely detection of dysplasia and early forms of cancer when treatment is most effective.

Perspectives and challenges in the fight against gastric cancer

The fight against gastric cancer requires a comprehensive approach, including improving screening programs, increasing awareness of risk factors, and implementing advanced endoscopic technologies. Global efforts should be aimed at reducing disparities in access to diagnosis and treatment, especially in regions with high incidence rates.

Focusing on modifiable risk factors, such as diet, smoking, and alcohol, as well as timely eradication of Helicobacter pylori, can significantly reduce overall incidence. Further research and innovation in the fields of endoscopy and molecular diagnostics will contribute to earlier and more accurate detection of gastric cancer, opening new opportunities for effective treatment and improved patient prognosis.

Sources

1. Rapid fire needling combined with Xiaoliu Jin Jianwei decoction improves gastrointestinal symptoms and gastric mucosal lesions in chronic atrophic gastritis. https://pubmed.ncbi.nlm.nih.gov/42007096/
2. A lifestyle-derived risk score for chronic atrophic gastritis: development and validation in 21,008 Chinese adults. https://pubmed.ncbi.nlm.nih.gov/42094894/
3. Endoscopic Features of Background Gastritis Associated With Remnant Gastric Cancer: A Multicenter Retrospective Study. https://pubmed.ncbi.nlm.nih.gov/41942357/
4. The Association Between Cancer Incidence and Heart Failure: A Systematic Review and Meta-Analysis. https://pubmed.ncbi.nlm.nih.gov/42449798/
5. Early Detection of Gastric Cancer: Linking Epidemiology, Pathophysiology, and Innovations in Digestive Endoscopy. https://pubmed.ncbi.nlm.nih.gov/42041640/
6. Helicobacter pylori, peptic ulcer disease, and colorectal cancer: a prospective study with genome-wide interaction analysis and Mendelian randomization. https://pubmed.ncbi.nlm.nih.gov/40883828/
7. Prevalence of Precursor Lesions in Gastric Adenocarcinoma Specimen: Insights into Pathogenesis in the United States Population. https://pubmed.ncbi.nlm.nih.gov/41317225/

The information provided in this article is for reference purposes only and should not be used for self-diagnosis or self-treatment. Always consult a qualified medical professional for an accurate diagnosis and an individualized treatment plan.