Poster Presentation Clinical Oncology Society of Australia 2014 Annual Scientific Meeting

Why are a large proportion of prostate cancer cases recorded as having “unknown” stage of disease in an Australian population-based registry? A study of possible health service factors (#274)

Qingwei Luo 1 2 , Xue Qin Yu 1 2 , David P Smith 1 3 , David Goldsbury 1 , 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

Aim
To identify possible explanations for why stage at diagnosis was recorded as “unknown” for prostate cancer cases in an Australian population-based cancer registry.

Methods
Linked data for prostate cancer cases registered in the New South Wales (NSW) Central Cancer Registry (CCR) in 2001-2007 and the NSW Admitted Patient Data Collection for 2000-2008 were analysed. Stage at diagnosis was determined by the CCR, using information received up to 4 months after diagnosis. We compared the inpatient hospital services received for up to one year after diagnosis by cases with stage recorded and with “unknown” stage and used multivariable logistic regression to examine factors associated with “unknown” stage.

Results
Of 35213 prostate cancer cases included in the analysis, 40.9% were recorded as having “unknown” stage. For cases without a hospital-reported prostate cancer diagnosis within 4 months after diagnosis, 76.5% had “unknown” stage. In those with a hospital-reported prostate cancer diagnosis in the 4 months after diagnosis, 6.8% of cases who had a radical prostatectomy and 33.3% of the remaining cases had “unknown” stage. For the latter group, factors related to having “unknown” stage were: having prostate-related procedures other than “imaging and transurethral resection of the prostate (TURP)” (e.g. biopsy or TURP only, adjusted odds ratio (OR) ranged from 1.37 to 1.86); attending a private hospital (adjusted OR ranged from 1.48 to 2.03); or having a day-only admission (adjusted OR=1.19, 95% CI: 1.05-1.35).

Conclusions
Nearly 60% of cases with “unknown” stage could be explained by a lack of a prostate cancer diagnosis in hospital records or by a lack of notifiable episodes of care for prostate cancer occurring up to 4 months after diagnosis. However, the available data did not provide an explanation for 31.9% of cases recorded as having “unknown” stage.