Increased incidence of breast cancer in southeast Netherlands between 1960 and 1989

: Trends in incidence, stage distribution and mortality of breast cancer were determined in the Southeastern Netherlands in 1960-1989. First and second primary breast cancers were analyzed separately. The incidence and mortality rates were age-standardised according to the European Standard Population. The incidence rate of first primary invasive breast cancer increased from 50 per 100,000 women per year in 1960-61 to 96 in 1988-89, and of second primary invasive breast cancer from 3.2 in 1965-66 to 7.8 in 1988-89. The incidence rate of first primary ductal carcinoma in situ (DCIS) increased from 0.3 per 100,000 women per year in 1975-76 to 2.8 in 1988-89 and of second primary DCIS from 0.06 in 1975-79 to 0.4 per 100,000 in 1985-89. The increase in first invasive primaries was observed in all age groups, but mostly at age 75 and over. The percentage with stage I tumours of the patients with a first primary invasive breast cancer increased from 7% in the sixties to 27% in the eighties, whereas the percentage of stage III and IV tumours combined, decreased from 39% in the sixties to 26% in the eighties. While age-adjusted incidence of first primaries almost doubled in the past thirty years, breast cancer mortality rose only slightly. However, breast cancer mortality showed a proportionate increase of total mortality from 4.5% in 1970-71 to 6.3% in 1988-89.(ABSTRACT TRUNCATED AT 250 WORDS)