Prostate Cancer
How does the impact vary across Australia?
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What is a prostate?
A prostate is a small, walnut sized gland that produces the seminal fluid to nourish and transport sperm.
Prostate cancer develops when abnormal cells in the prostate gland grow in an uncontrolled way. If undetected or left untreated, it can lead to death.
Global impact of prostate cancer
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Globally in 2020, prostate cancer was the second most diagnosed cancer (behind lung cancer) among men. However, it was the most common cancer diagnosed among men living in Europe, North America, Australia and New Zealand (excluding common types of skin cancers).
Impact in Australia
In Australia, after skin cancer, prostate cancer is the most common type of cancer found in men. It is also the second most common cause of cancer-related death among men in Australia.
Source: Cancer data in Australia. Australian Institute of Health and Welfare, 31 August 2023, https://www.aihw.gov.au/reports/cancer/cancer-data-in-australia
What about survival from prostate cancer?
Survival is often measured by ‘relative survival’, which compares people diagnosed with prostate cancer to the general population. For example, if relative survival was 100%, it would mean there was no difference between men diagnosed with prostate cancer and the general male population.
Relative survival for prostate cancer in Australia is currently 95% when measured 5 years after diagnosis. This means, on average, Australian men diagnosed with prostate cancer were 5% more likely to die within five years compared to men in the general population. However, prostate cancer survival rates for Australian men have improved over the last 30 years, with relative survival estimates increasing from about 60% in the late 1980s to now nearly 95%.
Cancer stages and survival
When a prostate cancer is diagnosed, it is important to assess how much the cancer has spread throughout the body. This is known as ‘staging’.
There are three broad categories of stage:
Localised cancer
The first is ‘localised’, in which the cancer is contained within the prostate, and can be referred to as Stage 1 cancer.
Regional cancer
The second broad staging category is known as ‘Regional cancer’ (or Stage 2 or 3), in which the prostate cancer is larger and has spread outside the prostate to nearby tissues or organs such as the bladder, rectum or the pelvic wall.
Distant (advanced cancer)
‘Distant’ or ‘advanced cancer’ (Stage 4), is when the prostate cancer has metastasised, meaning the cancer has spread to distant parts of the body such as bones, lymph nodes or lungs. This is still called prostate cancer even if the tumour is located in a different part of the body.
We can now look at how the average survival outcomes vary for groups of men diagnosed with different stages of prostate cancer.
Consider these 6 groups of 100 men, split into three pairs, with each pair representing men diagnosed in 1985 and men diagnosed in 2014. Men in each of these three pairs have been diagnosed with a distinct stage of prostate cancer.
We then follow them for ten years and estimate how many would have died (shown in red in the next frame) from prostate cancer during that time.
For the group of 100 men diagnosed with localised prostate cancer, the estimated number of prostate cancer deaths within 10 years of diagnosis reduced from 12 for 100 men diagnosed in 1985 to 3 deaths among 100 men diagnosed in 2014.
For the group of 100 men diagnosed with regional prostate cancer, the number of prostate cancer deaths within ten years reduced from 26 to 10.
For the group of men diagnosed with distant stage prostate cancer, the numbers reduced from 94 to 49.
Therefore, we can see survival has improved substantially over time, but it still depends on the stage at diagnosis. One reason why survival rates appear to have improved greatly between 1985 and 2014 is because we have become much better at detecting a prostate cancer that is not life-threatening. Alongside improved imaging and better treatments, this has lowered the overall risk of dying from prostate cancer.
What is known about the causes of prostate cancer?
While there are no known causes of prostate cancers, there are several factors that could increase the risk of a man being diagnosed with prostate cancer. These risk factors include:
- Increasing age
- Family history of prostate, breast or ovarian cancer.
- Certain genetic mutations
There is some evidence that smoking, being overweight, consuming an unbalanced diet, testosterone levels, occupational exposures and sexual history may also be associated with an increased risk, but the evidence is currently unclear.
How is prostate cancer detected?
The test most used to aid early detection of prostate cancer is the prostate specific antigen (PSA) blood test. This test can show changes in the prostate that may be caused by cancer but may also have other causes such as an enlarged prostate.
While widespread testing for prostate cancer through PSA testing has led to a reduction in advanced disease at diagnosis, it can also lead to the diagnosis of some very early and extremely slow growing prostate cancers that may not have caused any health problems had they been left untreated.
Naturally, locations in Australia where PSA testing is more common are likely to have a higher diagnosis rate of these slow growing cancers.
To know more about prostate cancer and its detection methods, click here.
Prostate cancer research
Research studies have long revealed that where people live can have an impact on their health and affect the likelihood of being diagnosed with chronic diseases, like cancer.
It is no different with prostate cancer. In 2018, Cancer Council Queensland, Queensland University of Technology, and other organisations launched the Australian Cancer Atlas (atlas.cancer.org.au), providing unique insights into how the impact of cancer, including prostate cancer, varies by small areas across Australia. The Australian Cancer Atlas is a free online tool, available for anyone to use.
Much of the information on prostate cancer in the Australian Cancer Atlas is based on data collected by State and Territory cancer registries across Australia. The information collected by cancer registries plays a critical role in understanding the burden of cancer. This data is then analysed using complex statistical models, that provide a way to generate stable estimates of prostate cancer in each small area, while also making sure the original data remain confidential
Let's take a look at some examples of how prostate cancer diagnosis and survival are displayed in the Australian Cancer Atlas.
Prostate cancer diagnosis rates across Australia
In the Atlas, areas coloured blue are below the Australian average, areas coloured red or orange are above the Australian average and areas coloured yellow are equal to the Australian average.
Areas with lower diagnosis rates
Lower than average diagnosis rates are found in Victoria and Tasmania as well as areas of Western and Northern Australia.
Areas with higher diagnosis rates
Most areas with higher-than-average prostate cancer diagnosis rates can be found in New South Wales, Southwest of Western Australia and Central Queensland.
Survival following a prostate cancer diagnosis across Australia
In the Atlas, the map for prostate cancer survival is dominated by the poorer-than-average rates, shown in red, across most geographical areas in Central, Western and Northern Australia, including areas of Victoria. In the Australian Cancer Atlas, we are reporting survival within 5 years of diagnosis.
Most of the areas with better than average survival rates for prostate cancer (shown in blue) are across parts of New South Wales (including Sydney), Southern parts of South Australia (including Adelaide) and Tasmania.
Let's compare the two maps of diagnosis rates and survival. The comparison will highlight how some areas with lower diagnosis rates have very poor survival outcomes. Similarly, some areas with higher diagnosis rates have much better survival outcomes.
See the maps below.
First, this is the map showing prostate cancer diagnosis rates. The blue areas are areas with low diagnosis rates, while the red and orange areas have higher diagnosis rates. Scroll down to see how these areas with lower diagnosis rates become areas with poorer survival.
This is the map of prostate cancer survival. Notice how for some geographical areas, the patterns for prostate cancer survival are in the opposite direction to those for prostate cancer diagnoses.
The contrast is even more pronounced in Victoria.
As well as in Northern parts of Australia.
What is causing this difference between incidence and survival?
The short answer is, we don't know. However, we do know these patterns are consistent with testing or an effect of early detection. This means prostate cancers detected through PSA testing, are more likely to be localised (or less serious) and have a better survival rate. This suggests areas Australia where there is a higher amount of PSA testing would have two characteristics:
1. A higher incidence of localised prostate cancers.
2. A lower incidence of advanced prostate cancer. Both characteristics would lead to better prostate cancer survival.
The following two hypothetical scenarios demonstrate the complexities of the relationship between PSA testing, diagnosis and survival. These highlight how difficult it can be to uncover the factors driving the observed geographical patterns in prostate cancer survival.
Note: These scenarios are hypothetical and designed to illustrate the complexities of PSA testing. The individuals depicted in the accompanying photos are for illustrative purposes only and do not represent real cancer patients.
Scenario #1
Consider a hypothetical male aged 50 years old (“Bob"). He has no symptoms suggesting prostate problems, however, his GP suggests prostate cancer testing. The PSA test is abnormal. “Bob” has a repeat PSA test, scans and a biopsy where small samples of tissue are taken from his prostate. The biopsy shows very early prostate cancer. After an anxious few months, after he considers active surveillance, radiation therapy and surgery, “Bob” finally decides to have surgery to remove the prostate. Unfortunately, the surgery causes side-effects for Bob that will last a lifetime. “Bob” will never know that his prostate cancer was growing so slowly that it would not have shortened his life or could have even been detected except for the GP’s suggestion. “Bob” dies at the age of 90 years, having survived 40 years after his prostate cancer was first diagnosed. “Bob” would have died at 90 anyway. PSA testing has had no impact on the length of “Bob’s” life, but the treatment related side-effects had a large negative impact on his quality of life.
Scenario #2
Consider another hypothetical scenario, with another man aged 50 years old (“Alan”). He has exactly the same experience as “Bob” with testing and cancer diagnosis and quality of life after treatment. However, in “Alan’s” case, the prostate cancer was an aggressive form. “Alan” is the 1 in 100 men who would have died of prostate cancer in 10 years had he not been tested, and the cancer removed. Like “Bob”, “Alan” dies at 90 years with a 40 year survival period. In “Alan’s” case, early detection saved his life.
Where can I get cancer information and support?
Cancer Council Queensland, along with the Cancer Councils across Australia, provide a free, confidential telephone support service available to everyone in the country to ensure nobody is left navigating cancer alone. Australians impacted by cancer can call this free service to gain information about cancer, as well as emotional and practical support.
Our 13 11 20 hotline can also refer callers to support programs and services in their local area.
How can I contribute to reducing the impact of prostate cancer in Australia?
By donating to Cancer Council Queensland, you can support services like accommodation lodges and transport to treatment, which can make a significance difference in a person's cancer journey.
Your donation can also contribute to cutting-edge research conducted at Cancer Council Queensland that aims to understand the underlying reasons for prostate cancer. This research will help improve prevention and management strategies and save thousands Australian lives.
So, join us in our mission to bring hope and healing to those affected by prostate cancer. Every donation, no matter the amount, can make a difference in the lives of many Australians.
How can I find out what is causing this difference between incidence and survival?
A recent Australian study has provided some information about geographical patterns in PSA testing. Until more detailed analyses are conducted to investigate how the geographical patterns in PSA testing correlate with the prostate cancer incidence and survival patterns, as well as information about stage of disease at diagnosis and management practices, it isn’t possible to know for sure what is driving these geographical patterns. Through further developments of the Australian Cancer Atlas, we hope to answer some of these questions.
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