Project summary

BACKGROUND

For New Zealand men, prostate cancer is the most commonly registered cancer. Māori men are less likely to be diagnosed with prostate cancer, but when diagnosed they are twice as likely to die. Despite two studies that suggest reduced mortality from prostate cancer in men that have been screened, uncertainty as to the benefits, the extent of complications arising from treatment and concerns about over-treatment has meant that universal screening has not been recommended. Opportunistic screening for prostate cancer is widely practiced by general practitioners in New Zealand. Treatment options in New Zealand vary and differences in outcomes of screening have not been evaluated in the local setting. There is evidence that treatment for prostate cancer can commonly cause moderate-to-substantial harms. We have less reliable information about the wider complications, including social and psychological impact. We also do not have a good understanding of the financial costs associated with diagnosis and treatment of prostate cancer in New Zealand and who pays.

THE STUDY

There are four phases to this study outlined below

Phase 1:GP PSA testing


We recruited 31 GP clinics in the Midland regions (eligible patient cohort of 36,000-enrolled men 40yrs and over).  Recruited clinics gave permission to track PSA testing done and the medtech system was searched to identify reasons for patient attendance on date of PSA test; symptoms; referral; diagnostic tests; treatment; etc.  Patient surveys were also undertaken to identify reasons why men believe they received a PSA test.  

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Phase 2: NZ cancer registry search


All prostate cancer registrations were obtained from the New Zealand Cancer Registry (NZCR) for the period 1990-2008 including information on age, ethnicity, stage at diagnosis, domicile code and whether death has occurred (for 3 years post-diagnosis). These data were linked to information retrieved from the Mortality Collection and death certificates and were analysed with regard to cause(s) of death for men with prostate cancer between 1990 and 2010. Relevant data was also extracted from the National Health Index and NMDS to establish the pathways and outcomes for individual patients.  These data were subsequently evaluated with regard to ethnic group, rural/urban residence and distance from a cancer centre to ascertain whether there were inequities in access and availability of treatment options. From this we examined epidemiological trends for prostate cancer incidence and mortality in NZ men aged 40 years and over.

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Phase 3: Identifying all new cases of prostate cancer (2007-2010)


For phase three, we would compose a list of all newly diagnosed patients in the four year period, 2007-2010.  We randomly selected 600 NHIs from the Midland region, identified from the NZCR.  We have recreated the cancer care pathways of all patients from original GP referral to post-treatment outcomes.  From this we will develop a decision tree to aid in understanding likelihood of outcomes for men, depending on age, stage.

We are also interested in understanding the costs of complications for each pathway.  We shall investigate the health care costs involved in the key pathways identified by our mapping exercises. An economic model will be developed to determine the costs and outcomes associated with each pathway of care. The model will allow us to explore the impact of different treatment options on costs and outcomes and enable us to undertake sensitivity analyses where the data are uncertain. We would aim to estimate the direct costs for each pathway, including those incurred in primary care, through the public health system and where appropriate costs incurred in specialist private practice. Costs would be measured over a 12 month period following the positive PSA test. 

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Phase 4: The costs and complications of prostate cancer


Whilst we know that treatment for prostate cancer can cause physical symptoms we also believe that, as with any cancer, there will be a psychological and social impact on the lives of patients. This has not been quantified in a population based sample of New Zealand men before. Complications and their impact on patients were identified using structured questionnaires to measure key outcomes. From our sample of men we have recruited a sample of 106 men aged 40 – 75 years of age to help us assess the costs and complications of treatment at an individual level. Fifty-seven partners of these men have also participated in this phase.  This has highlighted the indirect costs of living with prostate cancer, for both the patient and his partner. 

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Benefits

This study will help us improve the pathways of care for men with prostate cancer. It will help general practitioners with their decision making as to when to refer men after a PSA test. It will also better inform patients as to their likelihood of needing intense follow up for suspected prostate cancer. We also believe there will be important benefits in improving the pathways of care for men with diagnosed prostate cancer. Information from this study should allow us to gain more insight into the costs and complications from the treatment of prostate cancer.

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