Soft tissue sarcomas in Iceland 1955-1988. Analysis of survival and prognostic factors

From 1955 to 1988 a total of 129 cases (69 males and 60 females) of soft tissue sarcomas were diagnosed in Iceland, four at autopsy. The median age was 55 years (0-91). All the cases have been reviewed clinically and histopathologically and graded on both a three- and a four-point scale. The average age-standardized incidence was 1.8/100,000 for males and 1.6 for females. The tumour was most often localized in the thigh and retroperitoneal space. The most common histologic subtypes were malignant fibrous histiocytoma (22.5%), liposarcoma (18.6%) and leiomyosarcoma (16.3%). The 5- and 10-year survival rates (n = 125) were 38% and 29% respectively. Cox's multivariate analysis was performed on the following prognostic factors: age, sex, tumour localization, histopathologic subtype, tumour size, malignancy grade and year of diagnosis. The strongest prognostic factor was malignancy grade (IV vs I; p less than 0.001 and RR = 5.35 and III vs I; p = 0.017 and RR = 2.01) followed by tumour size (pT2 vs pT1; p less than 0.001 and RR = 3.09 and pT3 vs pT1; p = 0.002 and RR = 3.40) and year of diagnosis (p = 0.003 and RR = 0.96; corresponding to a 54% reduction in mortality risk during a 20-year period).