USRF Research

Swedish Study Shows Prostate Cancer
May Become Aggressive Many Years After Diagnosis

July 21, 2004

Natural History of Prostate Cancer: a Late Killer

Abstracted from:
WebMD and Johansson's JAMA article

Orebro, Sweden (June, 2004) – A major advance in knowledge of prostate cancer (CaP) natural history was revealed this month with publication of the largest, longest study of disease progression yet conducted. In a recent JAMA article, Johansson and colleagues from Sweden followed 223 men with early CaP---left untreated until tumor progression; the disease often remained indolent for up to 15 years, then after that long interval, mortality from CaP increased dramatically. The finding will force many men with CaP, especially men with long life expectancy, to re-think treatment options.

The study is important because previous natural history studies of CaP were hampered by small numbers, loss of men to various treatment options, and/or insufficient follow-up. In rural Central Sweden, where this study was set, more than 98% of the eligible men having localized CaP were included in the study. Average observation period was 21 years, with 91% of the men followed until death. Not a single man was lost to follow-up. Mortality from CaP increased from 15/1000 person-years during the first 15 years of follow-up to 44/1000 beyond 15 years (p<0.01).

The key figure is reproduced here.

Average age at diagnosis was 72 years. 48% of the tumors were incidental discoveries in prostate tissue removed for obstruction; the remainder had a palpable abnormality. PSA screening was not used; recruitment was between the years 1977 – 1984.

In an accompanying editorial, Drs. Neugut and Grann of Columbia University state that the acceleration in CaP mortality after 15 years could be caused by (1) the advent of PSA testing and increased detection of disease, (2) emergence of more aggressive tumors, (3) or perhaps even by cardiovascular diseases associated with estrogen treatment used in this study for CaP progression.

With regard to CaP screening, Neugut and Grann state that “…a horizon of 15 to 20 years…(may) be necessary to really observe the impact of PSA screening on prostate cancer.”



this is a navigational image map, please load this image to continue.