Each year in Australia, doctors will tell around 16,700 men that they have prostate cancer. This is equal to one diagnosis every 25 minutes.
For some men, this will lead to regular visits to the doctor to monitor the tumour. No treatment may be needed. Others will require active treatment with radiation, hormone therapy or chemotherapy.
Unfortunately, over 3,150 men die of prostate cancer each year in Australia.
September is Prostate Cancer Awareness Month. To learn more about this condition, and hear about the research seeking new and improved treatments, I talked to Associate Professor Renea Taylor.
Associate Professor Taylor co-leads the Prostate Cancer Research Group and is Deputy Head of the Monash Biomedicine Discovery Institute Cancer Program. Her research focuses on finding an effective treatment for men with aggressive prostate cancer, for which there currently remains no cure. Here is what Renea had to say.
Can you please start by explaining what the prostate gland does and where it is in the body?
Firstly, only men have a prostate gland. It is part of the male reproductive system.
The prostate gland sits below the bladder near the rectum. It surrounds the urethra – the passage in the penis through which urine and semen pass. The prostate gland produces most of the fluid that makes up semen. This fluid provides energy and protection for the sperm, so it can survive its journey to fertilise the female egg (or ova).
The prostate needs the male hormone testosterone to grow and develop.
The prostate is often described as being the size of a walnut and it is normal for it to grow as men age. Sometimes this can cause problems, such as difficulty urinating. These problems are common in older men and not always symptoms or signs of cancer.
Not many people will have heard about the prostate gland. Why is that?
There are a few reasons we don’t hear too much about the prostate gland.
The first is that because the prostate gland is a private part of the man’s body and related to sex and reproduction, many people find this difficult of awkward to talk about. A lot of people don’t discuss these things freely, so it is one of those health topics that often goes under the radar.
The gland itself is located in an awkward position. The only ways to access the prostate gland are through the urethra or rectum – depending on the procedure needed. Again, these are topics that don’t really come up in everyday conversation.
In some men, the prostate gland can become large and cause urinary problems. This condition is called benign prostatic hyperplasia (BPH) and is fairly common. It affects around half of men by the age of 80. Symptoms of an enlarged prostate gland include discomfort when urinating, blocked flow of urine and needing to go to the toilet more often than usual. Many men find this difficult to talk about and so don’t seek assistance.
What is prostate cancer?
Prostate cancer is a common cancer in the aging male. It usually occurs in men over 50 years of age. The biggest risk factors for prostate cancer are older age and family history. Having a close relative who has had prostate cancer increases your risk.
Prostate cancer happens when abnormal cells in the prostate gland start to multiply uncontrollably. In most men, this happens over a long period of time, as the cancer is very slow-growing. This means many men who have low-grade prostate cancer can live for a long time without noticing any symptoms.
However, high-grade prostate cancer spreads quickly and can be deadly. In these cases, appropriate management is key. This is where I want to help with my research.
How is prostate cancer detected?
The most common test for prostate cancer is the Prostate Specific Antigen (PSA) blood test. PSA is a protein in the blood that can be higher in men with prostate cancer. However, even if the results show PSA is high, it doesn’t necessarily mean you have cancer. Other prostate conditions can cause a high PSA reading. Additional tests can then be done to see if it is prostate cancer.
How is prostate cancer treated?
For 8 out of 10 men diagnosed with a prostate cancer, the tumour will be confined to the prostate gland. For many men, the immediate treatment will just be active surveillance – where the doctor will monitor the cancer to make sure it isn’t growing or spreading. Other treatments can include surgery (removal of the prostate) or radiotherapy.
If prostate cancer spreads outside the prostate gland, the most common way to treat this is to reduce testosterone levels. This is because testosterone is one of the key hormones that helps prostate cancer to grow. This therapy is called ‘androgen deprivation therapy’, as testosterone is a type of androgen, and the medication deprives the body of this hormone.
Most men respond well to androgen deprivation therapy, and see a rapid decline in their PSA level. Sometimes, however, the cancer can change and continue to grow even when testosterone is no longer present. This leads to what is called a castrate-resistant prostate cancer (CRPC), which is an advanced stage of the disease. This type of cancer requires chemotherapy and other newly available treatments. A major focus of my research is to improve treatments for this type of cancer.
What are the challenges in improving treatments for aggressive prostate cancer?
The first challenge is identifying the type of cancer early, so treatment can be tailored.
While the results of the PSA test can tell you about prostate health, they don’t tell you whether the high PSA level is due to cancer. Then if it is, it doesn’t give any information about whether the cancer is a more typical, slow-growing type or a rare and more aggressive form, and doesn’t let you know whether you require immediate treatment.
Finding better methods that give you this information would be much better for men, their families, and their doctors.
New methods could look for different biomarkers in the cancer tissue, or alternatively blood or urine. But in order to know what to look for, we need to know more about these cancers.
How is your research helping to identify aggressive prostate cancers?
My research is trying to identify better markers that tell us about the type of cancer – whether it is aggressive or slow-growing, and what treatment is needed.
We collect tumour samples donated from patients at 12 different hospitals across Melbourne and use them to develop new models of cancer in our lab. We look at these samples down the microscope to look for clues to understand what makes aggressive cancers so aggressive. For example, can we see microscopic features that are specific to aggressive cancers? These discoveries will improve our ability to identify and diagnose aggressive cancers early.
We also use the donated samples to grow cancer tissue in the lab. This gives us the opportunity to learn more about the different types of prostate cancers and understand their growth patterns. Once we have this understanding, we can work out how to disrupt this process, and develop new treatments. We can also test new drugs and identify the most promising treatments that can be tried in patients.
It is important to have access to new samples all the time, as there are many different forms of prostate cancer, and they evolve and change all the time. This means that different treatments are required to treat different types of cancer. Identifying the type of cancer is therefore very important. It means treatment can be tailored for each person to provide the best possible outcome.
Our collection of prostate tumour samples is one of the world’s largest collections. We would struggle to do our research without this incredible access to samples. We are very grateful to the men who donate their tissue to make our research possible.
What can men do to have a favourable outcome from prostate cancer?
The best outcomes from prostate cancer are when they are detected early. This means having regular PSA testing, particularly if you know you are at risk. Knowing your family history is important to understand this risk.
What would you like everyone to know about prostate cancer?
It is important for men to be vigilant about their prostate health and have regular check-ups.
Not all cancers are equal, so each patient will benefit from individualised treatment.
Research is really important as it is the only way to find better treatments to prevent unnecessary deaths from prostate cancer.
For more information and useful resources
Preclinical Models of Prostate Cancer: Patient-Derived Xenografts, Organoids, and Other Explant Models. GP Risbridger, R Toivanen and RA Taylor. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6071547/
The Prostate Cancer Foundation of Australia – For more information about prostate cancer and support, visit https://www.prostate.org.au/