Gastric cancer in Tasmania (1978-1992).

A detailed analyses of gastric cancer incidence and mortality rates in Tasmania was done using fifteen years (1978-1992) of population based Tasmanian Cancer Registry data. The age standardised incidence rates for the period were 12.5 per 100,000 men (95% CI 11.4-13.6) and 5.2 per 100,000 women (95% CI 4.6-5.8). The age standardised mortality rates were 10.6 per 100,000 men (95% CI 9.6-11.6) and 4.1 per 100,000 women (95% CI 3.5-4.6). Male:Female ratio of mortality rates was 2.6. Gastric cancer mortality rates have now significantly declined among males (p = .03) and females (p = .02). No significant decline was observed for incidence rates among males (p = .1) and females (p = .3). For cases overall, there was a preponderance of intestinal type of gastric cancer (76.5%). No significant trend over time was observed in the mean rate of occurrence of intestinal or diffuse type of gastric cancer. The ratio of intestinal: diffuse was 6.5 for all ages. Among males, a significant (p = .03) upward trend in the incidence was observed for proximal tumours, while no such trend (p = .07) was observed among women. A significant decline in incidence of distal tumours was observed for males (p = .000) and females (p.007). Male:Female ratio for proximal tumour was 4.7:1. The results suggests that Tasmanians may have been a population at high risk of gastric cancer.