Striking differences in the epidemiological picture of breast cancer in urban and rural areas in Poland.

Poland is a European country of medium female breast cancer risk but a steady, mean incidence growth of 3.5% per year makes this cancer the most frequent malignancy and a leading cause of cancer-related deaths among the women of the 1980s. Our analysis is based on data collected by the Warsaw Cancer Registry in the years 1963-1987. The crude incidence rate in Poland doubled against 1963 and was nearly 40/100,000 in 1988. In 1988 eight thousand women developed breast cancer. In Poland, the incidence of 37.7 was higher in Warsaw than the rate of 16.6 obtained for Warsaw Rural Areas (WRA) in 1963. The trend continued until 1988 to reach 59.7 and 33.5 in the respective areas. Incidence rapidly grew with age, starting in the group of 30 to reach its peak of 149.2 at 65 and over in Warsaw and 86.6 in WRA. Mortality rates in Warsaw grew from 16.6 in 1963 to 30.7 in 1988 and, from 10.8 to 17.4 in WRA in the respective years. The urban/rural ratio declined from 1.7 to 1.5 during this period. The unfavourable proportion (patient distribution according to clinical staging in Warsaw was: 0 + I-17.2%; II-34.1%; III-29.1%; IV-23.6%. The relative 5-year survivals in Warsaw were 58.7% and they improved little compared to the former periods. These figures were even lower in WRA and they showed a downward trend for women aged over 65. A steady increase in breast cancer risk observed after 1963 and the large proportion of advanced breast cancers diagnosed, were followed by poor results of treatment causing about 5,000 breast cancer deaths in Poland annually.