Increased survival in patients diagnosed with Hodgkin's disease in Tasmania, 1972-1992

Background: It has been shown that in certain populations the prognosis of Hodgkin's disease (HD) has improved markedly since the late 1960s. This has not been formally demonstrated in an Australian population. Aims: To review all patients in Tasmania diagnosed with HD between 1972 and 1992, and to ascertain whether variation in survival is evident in this group over this period. Methods: Tasmanian patients with HD diagnosed from 1978 to 1992 were identified retrospectively from the Tasmanian Cancer Registry database. Identification of those diagnosed prior to 1978 was obtained from a previously published data set. To be valid for inclusion, subjects were required to have been diagnosed between January 1972 and December 1992, enabling a minimum four year follow up period. Survival was assessed by contacting patients' medical practitioners and by examining the most current electoral roll, medical records, and the register of births, deaths and marriages. Univariate and multivariate analyses were performed of the influence on prognosis of age, sex, histological subtype and epoch of diagnosis; information concerning stage of disease was not available. Results: During the period of this study 206 patients were newly diagnosed as having HD. Comparisons of cases diagnosed in the successive seven-year epochs 1972-8, 1979-85 and 1986-92 revealed a significant increase in survival duration (p=0.023), with ten year survival rates of 46%, 55% and 73% respectively. In a multivariate analysis adjusting for age, sex and histology, each successive epoch was associated with an estimated 28% reduction in the death rate relative to the preceding epoch (p=0.022). Conclusions: There was a significant improvement in the survival duration of patients diagnosed with HD in Tasmania over the period 1972-92, which was possibly due to a combination of better diagnostic techniques and more effective treatments.