Five-year survival of women with breast cancer in northern Alberta.

Five-year survival rates for all 519 women with breast carcinoma in northern Alberta in 1971 and 1972 were analysed with the use of data from the computerized northern Alberta breast registry and the Alberta cancer registry. The relative 5-year survival was 73%, which is higher than most rates reported from other centres. Lymph node involvement was significant as a prognostic factor, with the relative 5-year survival falling from 92% in the group without lymph node involvement to 58% in the group with three or more involved nodes. The prognosis was also significantly affected by the stage of the disease according to the 1973 TNM classification: the 5-year survival rates ranged from 88% for patients with stage 1 disease to 17% for those with stage IV disease. Women 40 to 59 years of age had a higher survival rate (79%) than those under 40 years (65%) or over 60 years (66%) of age. Analyses by 5-year age groups showed that women 35 to 39 years old had a particularly poor survival rate (59%). Postmenopausal women less than 55 years old had a higher survival rate than did perimenopausal or premenopausal women in the same age group. Further follow-up is indicated to correlate possible high-risk factors with survival.