[Mortality of gastric cancer in Catalonia, Spain: geographical distribution and time trends from 1986 to 2000]

The striking geographical pattern of gastric cancer mortality in Spain: environmental hypotheses revisited

BACKGROUND

Gastric cancer is decreasing in most countries. While socioeconomic development is the main factor to which this decline has been attributed, enormous differences among countries and within regions are still observed, with the main contributing factors remaining elusive. This study describes the geographic distribution of gastric cancer mortality at a municipal level in Spain, from 1994-2003.

METHODS

Smoothed relative risks of stomach cancer mortality were obtained, using the Besag-York-Molliè autoregressive spatial model. Maps depicting relative risk (RR) estimates and posterior probabilities of RR being greater than 1 were plotted.

RESULTS

From 1994-2003, 62184 gastric cancer deaths were registered in Spain (7 percent of all deaths due to malignant tumors). The geographic pattern was similar for both sexes. RRs displayed a south-north and coast-inland gradient, with lower risks being observed in Andalusia, the Mediterranean coastline, the Balearic and Canary Islands and the Cantabrian seaboard. The highest risk was concentrated along the west coast of Galicia, broad areas of the Castile & Leon Autonomous community, the province of Cáceres in Extremadura, Lleida and other areas of Catalonia.

CONCLUSION

In Spain, risk of gastric cancer mortality displays a striking geographic distribution. With some differences, this persistent and unique pattern is similar across the sexes, suggesting the implication of environmental exposures from sources, such as diet or ground water, which could affect both sexes and delimited geographic areas. Also, the higher sex-ratios found in some areas with high risk of smoking-related cancer mortality in males support the role of tobacco in gastric cancer etiology.

Tendencia de la mortalidad por cáncer en Andalucía entre 1975 y 2003

BACKGROUND AND OBJECTIVE

To describe cancer mortality trends in Andalusia for cancer as a whole and for their main locations, by age and gender groups during 1975-2003.

MATERIAL AND METHOD

Mortality rates age and gender-adjusted have been estimated through cancer mortality data coming from mortality and polpulation official statistics. Joinpoint regression analysis has been used in order to quantify trends and their points of change.

RESULTS

Cancer as a whole has showed a descending trend among women and an ascending trend among men, for the period 1975-2003. Annual change rates were -0.45% and 0.42% for women and men respectively, and both of them, statistically significant (p < 0.05). By age, except for the elder group, a fall is noted, both among women and among men. Among women, breast cancer was the first cause of cancer death; in 1993 it appeared a statistically significant change from ascendent to descendent trend. Among men, lung cancer was the first mortality cause; in 1996 appeared a significant trend change and it began to go down. Colon and rectum cancer was the second one in magnitude, both among men and women, but far from the first one and with an ascendent trend, specially among men.

CONCLUSIONS

Cancer mortality shows a descending trend among andalusian women, with a similar rate to the Spanish average. Among men, the trend is ascendent with a higher magnitude than the national average.