Breast cancer incidence in Metro Manila and Rizal province: 1980-1992.

Incidence was derived from published data from two population-based registries--the Philippine Cancer Society-Manila Cancer Registry, and the Department of Health-Rizal Cancer Registry, which covered 8.5 million residents (1990 census) of a 1674 sq. km area that comprises Metro Manila and Rizal province. 13 registry clerks actively sought new cancer cases in 96 hospitals and 30 Civil Registry offices. Both registries are members of the International Association of Cancer Registries and receive continuing professional assistance from the International Agency for Research on Cancer. For the period 1988-92, the combined age-standardized incidence rate (ASR) was 43.4 per 100,000 females, making breast cancer the second most common following lung cancer, and the highest among women. Breast cancer ASR in the Manila Registry was the highest in Asia with the exception of the Jews in Israel. Age-specific rates began to rise steeply starting at age-group 30-34 years and peaked at 196.6 for age-group 70-74 years. There were significant differences between cities and municipalities. The rates in the oldest and most urbanized cities were similar to some populations in Europe, South America, and Oceania, and were almost 3 times those of residents in rural municipalities whose new rates were similar to some Asian and African populations. The ASR has doubled in the 13-year period between 1980 and 1992. While the combined rates were still lower than those of Filipino migrants to Hawaii, San Francisco and Los Angeles, rates in some cities had approximated those observed in the migrant populations.