Published today in the Medical Journal of Australia, the study included 2724 men from 11 public and six private Victorian hospitals. The men were followed up 12 months after diagnosis.
The data was then compared with the numbers from a study of the management of men with prostate cancer who were diagnosed in 1993.
The authors found a drop in the average blood level of the prostate-specific antigen (PSA) at diagnosis compared with the 1993 study, suggesting much earlier diagnosis.
Most patients (93 per cent) were diagnosed with localised disease (cancers confined to the prostate gland), and nearly half of them were at intermediate risk of disease progression.
A year after diagnosis, 41 per cent of men at low risk of progression had received no active treatment, while 55 per cent at intermediate risk had undergone a radical prostatectomy and 12 per cent at high risk had received no active treatment.
Similarly, the percentage of men receiving no active treatment declined from 36 per cent in 1993 to 23 per cent in 2008–2011.
“Our finding that 71 per cent of men received surgery, radiotherapy and/or brachytherapy contrasts with results of the 1993 Victorian study, in which 25 per cent of men received initial treatment with curative intent,” Dr Evans said.
“There has also been a dramatic ‘stage migration’ towards earlier diagnosis of prostate cancer — the vast majority of men in our study were diagnosed with localised disease and only 3.3 per cent were diagnosed with metastatic disease (spread of a cancer throughout the body).”
Men aged over 75 years were more than 10 times as likely not to receive active treatment as those younger than 55 years.
The Medical Journal of Australia is a publication of the Australian Medical Association.
The Prostate Cancer Registry was established as a rapid case-ascertainment registry in 2009 to monitor patterns and quality of care for Victorian men diagnosed with prostate cancer.