Downward trend in prostate cancer mortality in Quebec and Canada

Purpose: if new treatment strategies and screening for prostate cancer are effective they should reduce prostate cancer mortality. In this review we m onitored prostate cancer mortality rates in Quebec and in Canada. Materials and Methods: We obtained data on all deaths from prostate cancer between 1976 and 1997 in Quebec, and 1976 and 1996 in Canada. We calculated age standardized mortality rates and assessed changes with time. Results: Prostate cancer mortality rates increased regularly until 1991 in Quebec and Canada. After 1991 the rates decreased moderately until 1995 and then more markedly in 1996. There was a further decline in 1997 in Quebec. Overall, age standardized prostate cancer mortality rates declined by 23% in Quebec between 1991 and 1997, and by 9.6% in Canada between 1991 and 199 6. The mortality decline was observed for all age groups but was more prono unced among men younger than 75 years. Conclusions: Until 1995 the trends in prostate cancer mortality in Quebec a nd Canada were similar to those observed in the United States. Our data sug gest that a sharper decline has occurred since 1995. It is of primary impor tance to identify the causes of the mortality decline. As prostate cancer m ortality rates declined relatively early after the initiation of widespread screening with prostate specific antigen, it is unlikely that screening ha s as yet contributed in a major way to the decline. It is more likely that the mortality reduction is a consequence of better prostate cancer manageme nt or improved treatment modalities.