Epidemiologic features of rapidly progressing breast cancer in Tunisia.

A form of breast cancer characterized by rapid disease progression, inflammation, and edema is found in approximately 55% of the breast cancer patients presenting at the Institute Salah Azaiz, Tunis (Tunisia). In 581 patients seen between January 1, 1969, and December 31, 1974, we examined age, place of residence, reproductive history, delay in seeking treatment, and blood gropu as potential risk factors to determine the distinction between the rapidly progressing disease and the less aggressive form. Rural residence, blood type A, and recent pregnancy are risk factors among premenopausal women, but older age, rural residence, blood type A, late menarche, and delay in diagnosis are associated with postmenopausal rapidly progressing breast cancer. The most significant risk factors were rural residence and blood type A. Rapidly progressing breast cancer was diagnosed in two of every three breast cancer patients coming from a rural environment. Forty-three percent of 203 patients with rapid disease progression were blood type A, a significantly higher percentage than the 33% found in the general Tunisian population and the breast cancer patients without evidence of rapidly progressive disease. We observed that the risk factors for disease progression were quite different from those reported to influence the incidence of breast cancer.