Evolution of treatment for Hodgkin's disease: a population-based study of radiation therapy use and outcome

To examine changes in radiotherapy (RT) use, cause-specific survival (CSS), and overall survival (OS) in a population-based cohort of Hodgkin's disease (HD) patients diagnosed from 1982 to 1996.

Adult patients with HD diagnosed from 1 January 1982 to 31 December 1996 (n = 3957) were identified from the Ontario Cancer Registry. The cohort was divided into three consecutive 5-year periods: 1982-1986, 1987-1991, and 1992-1996. RT use, CSS and OS in each of these three periods were compared. For the entire cohort, the cumulative incidence of different causes of death was calculated.

The proportion of patients receiving RT within 11 weeks of diagnosis declined over the three consecutive periods (25.1%, 15.6%, 11.7%, P < 0.001), as did the proportion receiving RT within 45 weeks (57.0%, 51.0%, 48.1%; P < 0.001). There was a significant increase in 5-year CSS over time (81%, 87%, 89%; P < 0.001), and OS (72%, 77%, 82%; P < 0.001), which remained significant in multivariable analyses. The cumulative incidence of death from causes other than HD was equal to the incidence of HD-related death within 12 years of diagnosis.

There was a significant decline in the use of RT as the primary treatment modality and as part of the initial management of HD from 1982-1996 in Ontario. A greater proportion of patients received their RT after a delay consistent with the receipt of prior chemotherapy. There was also a significant increase in the CSS and OS over this period. These findings are in keeping with the adoption of effective chemotherapy in the treatment of HD.