Oral Presentation Clinical Oncology Society of Australia 2014 Annual Scientific Meeting

A population-based study of progression to metastatic prostate cancer in Australia (#123)

Qingwei Luo 1 2 , Xue Qin Yu 1 2 , David P Smith 1 3 , Dianne L O'Connell 1 2 4 5
  1. Cancer Research Division, Cancer Council NSW, Sydney, NSW, Australia
  2. Sydney School of Public Health, University of Sydney, Sydney, NSW, Australia
  3. Griffith Health Institute, Griffith University, Gold Coast, QLD, Australia
  4. School of Medicine and Public Health, University of Newcastle, Newcastle, NSW, Australia
  5. School of Public Health & Community Medicine, University of New South Wales, Sydney, NSW, Australia

Aims
There are no population-wide studies with sufficient follow-up that describe and quantify prostate cancer progression to metastatic disease. We used population-based data from the New South Wales Central Cancer Registry (CCR) to describe the patterns of progression to metastatic disease in Australian men diagnosed with non-metastatic prostate cancer.

Methods
Data for all non-metastatic prostate cancer cases diagnosed 1993-2002 and followed to the end of 2007 were analysed. The outcome was progression to metastatic disease, identified by metastatic episode notifications in the CCR or by prostate cancer death. Factors associated with metastatic disease progression were identified using Cox regression models.

Results
Of the 32643 men with non-metastatic prostate cancer at diagnosis 43.1% had localised disease, 5.1% had regional spread and 51.9% had unknown stage. After a median of 7.1 years of follow-up 6708 (20.6%) cases had developed distant metastases. The risk of developing metastatic disease was significantly higher for those with regional (adjusted HR=2.65, 95% CI: 2.40-2.93) or unknown initial stage (adjusted HR=1.70, 95% CI: 1.61-1.80), for older men (adjusted HR range: 1.43-2.73), and those living in regional or rural areas (adjusted HR range: 1.11-1.24) or more disadvantaged areas (adjusted HR range: 1.09-1.12). The risk of developing metastatic disease decreased over calendar time (adjusted HR=0.98, 95% CI: 0.97-0.99 per year).

Conclusions
After a median follow-up of 7.1 years more than 1 in 5 men diagnosed with non-metastatic prostate cancer developed distant metastases. The estimated overall risk of developing metastatic disease could be a useful aid in discussions of the prognosis of non-metastatic prostate cancer between clinicians and patients, and the geographical disparities identified can inform the planning of required cancer services.