Differential trends in the intestinal and diffuse types of gastric carcinoma in the United States, 1973-2000: increase in the signet ring cell type.

CONTEXT

During the last 50 years, the incidence and mortality of gastric cancer has declined in many countries. This decline has primarily included the intestinal type (Lauren classification). However, there is an impression among pathologists that the diffuse type, especially the signet ring cell subtype, has become more prevalent.

OBJECTIVES

Using data from the Surveillance, Epidemiology, and End Results (SEER) Program of the National Cancer Institute, we analyzed the trends of the 2 primary types (intestinal and diffuse) of gastric carcinomas from 1973 through 2000.

DESIGN

Trends in age-adjusted rates were determined for gastric carcinomas through the SEER statistical program (SEER*Stat), which is available on the Internet to the public.

RESULTS

During the period studied, the intestinal type continued to decline in males, females, African Americans, and whites. The intestinal type was more common in males than in females and more common in African Americans than in whites. In contrast, a consistent increase in the rate of the diffuse type of gastric carcinoma was seen during this period. The rate increased from 0.3 cases per 100 000 persons in 1973 to 1.8 cases per 100 000 persons in 2000. This increase was seen in males, females, African Americans, and whites. The predominant increase occurred in the signet ring type.

CONCLUSIONS

The results indicate a progressive decrease in the incidence of the intestinal type of gastric cancer and an increase in the diffuse type of gastric carcinoma, especially the signet ring cell type. The clinical implications of the increase are considered.