Anatomical Distribution of Gastric Cancer

Geographical Variation

In Western countries, such as the United States and Western Europe, gastric cancer tumors are predominantly located in the proximal lesser curvature, cardia, and gastroesophageal junction, according to the National Comprehensive Cancer Network 1
A dramatic shift in the location of upper gastrointestinal tumors has been observed in North America and Europe in recent years, with a marked decrease in intestinal-type gastric cancers in the distal stomach and an increase in diffuse-type gastric cancers in the proximal stomach 2
In low- and middle-income countries, distal stomach tumors continue to predominate, unlike the trend observed in high-income countries 2
In Japan and other parts of the world, non-proximal (distal) tumors remain predominant, in contrast to the incidence trends in the West 1

More than 95% of gastric cancers are adenocarcinomas, which are typically classified according to anatomical location (cardia/proximal or non-cardia/distal) and histological type (diffuse or intestinal), as recommended by the National Comprehensive Cancer Network 3
The diffuse type is characterized by poorly differentiated and non-cohesive tumor cells with a signet ring or non-signet ring morphology, and is more prevalent in low-risk areas, with a tendency to localize in the proximal stomach 3
The intestinal type tends to form a mass lesion, is characterized by variably differentiated tumor cells arranged in a tubular or glandular pattern, and is more common in high-risk areas, with a predominance in the distal stomach, although its incidence is decreasing in Western countries 3

The location of the tumor in the stomach (cardia, fundus, body, antrum, and pylorus) and its relationship with the gastroesophageal junction for proximal tumors should be carefully recorded to aid in treatment planning and follow-up exams, as suggested by the National Comprehensive Cancer Network 4
The Siewert classification is important for proximal tumors and should be evaluated as part of the diagnosis, according to the National Comprehensive Cancer Network 3
The location of the tumor influences the surgical approach and treatment strategies, as recommended by the National Comprehensive Cancer Network 1