Differences in the birth-cohort patterns of gastric cancer and peptic ulcer

Abstract

Aim: The aim of this epidemiological study was to follow the time trends of mortality from gastric cancer and compare them with those of gastric and duodenal ulcer.

Methods: Mortality data from Denmark, England & Wales, Italy, Japan, Switzerland and the United States of the past 57-130 years were analysed. The age-specific death rates were plotted against the period of death as period-age contours and against the period of birth as cohort-age contours.

Results: The long-term time trends of gastric cancer mortality were found to rise among generations born during the 18th century until the first half of the 19th century and then decline in all subsequent generations. The rise and fall of gastric cancer preceded similar birth-cohort patterns of gastric and duodenal ulcer by about 10-30 years. With the exception of gastric cancer in the USA, similar birth-cohort phenomena were seen in all countries. In general, similar temporal patterns were also seen in men and women analysed separately.

Conclusions: The time trends of mortality from gastric cancer are shaped by an underlying birth-cohort pattern that resembles similar patterns of peptic ulcer mortality. The occurrence of birth-cohort phenomena in gastric cancer and peptic ulcer suggests that additional secular trends besides changes in the infection with Helicobacter pylori must have contributed to the peculiar long-term behaviour of these diagnoses.