Trends in diffuse type of gastric cancer: focus on younger women.

Abstract

Gastric cancer (GC) incidence has been decreasing over the last decades; however, there are uncertainties in trends and proportional distribution of the diffuse type. GC incidence data were extracted from the population-based Friuli Venezia Giulia Cancer Registry. GC types (diffuse vs. others) were compared in relation to age at diagnosis, calendar years, and sexes. Between 1995 and 2021, diffuse GC accounted for 10.2% of all GCs. The proportion was greater among individuals aged <45 years, 34.0% in women and 25.7% in men. An increasing proportion over time was observed, in particular in women (from 9.9% in 1995-2000 to 14.10% during 2011-2021). In the last decade (2011-2021), a decreasedincidence of all GC was observed, reaching an age-standardized rate (world standard) of 1.4/100,000 for men and 1.2/100,000 for women. Rates of diffuse GC were 0.3/100,000 in younger population. Although the overall GC incidence is decreasing, the percentage of diffuse GC is increasing in the younger population, particularly in women. Reasons for the increased proportion of diffuse-type GC within younger women remain uncertain, possibly related to the decreased exposure to risk factors for other GC histotypes.