So November is Prostate Cancer Awareness Month and also Movember. This is a favourite time of the year for most men as instantaneous societal approval is given for them to ditch the razor and grow a moustache. Sadly, most women are less keen on this sudden sprouting of facial hair. However, at the end the day the awareness and huge fundraising boost to Men’s Health is massive and it’s a month to celebrate. Interestingly, there are new ways of raising money other than simply growing a moustache; including moving for 60km, hosting a Mo-ment or just doing some gruelling test of physical endurance. Check out their website.
So let’s switch gears a get into the specific topic of prostate cancer. The first question to address is where and what is the prostate?
It’s a gland about the size of a walnut sitting just below your bladder. Its function is basically to secrete protective and nutritious fluid (also known as the seminal fluid) to ensure sperm can reach their ultimate destination. Put simply, its role is to aid in reproduction of the species.
So now that we know the basics about the prostate lets discuss how it can become abnormal. Basically the major abnormal finding is enlargement. As you age your prostate grows just like your eyebrows and ear hairs. This is called simple or benign enlargement (also known as benign prostatic hyperplasia) and is not a cancer. This growth can lead to urinary symptoms like a weak stream, dribbling at the end and frequent bladder emptying. These same symptoms can also indicate prostate enlargement due to cancer. So if you have any of these symptoms pick up the phone now and book yourself into your GP. The GP will take a detailed history, particularly focusing on any family history of prostate cancer. Depending on your history, symptoms, age and family history the GP will then discuss prostate cancer screening tests.
Do I need to have rectal examination?
Well, there are mixed views on this question. The procedure involves a lubricated gloved finger being inserted up the bum. Obviously men don’t look forward to internal examinations, however, all urologists (surgeons who treat prostate cancers) strongly recommend that a digital rectal examination is performed at the time a prostate cancer blood test is taken. This blood test is called the PSA and its short for prostate specific antigen.
The challenge with the PSA blood test is that there is no ‘normal value’. The PSA is dependent on many factors including your age and the size of your prostate. Remember your prostate grows as you age, so the PSA goes up over time too. To this day, it remains a very debatable screening test for detecting lethal prostate cancers. What do the expert governing bodies think about PSA screening? The Cancer Council of Australia is on the fence. It states that men with average risk for prostate cancer who have been informed of the benefits and harms of testing can choose to have a PSA screening testing. In this scenario, a PSA should be performed every 2 years from age 50 to 60. If the PSA is greater than 3.0ng/mL more investigation is needed. In short, men who understand what they are getting themselves into with PSA testing can opt for screening.
More specifically, the Cancer Council does not recommend PSA testing at age 40 or for men older than 70 as the harms outweigh the benefits. But if you have a higher than average risk, because your father had prostate cancer, then PSA testing is recommended from age 45. The Cancer Council is more decisive on the role of a digital rectal examination. This is not recommended on top of the PSA test. One of the reasons for this statement is not deter men from seeing their GP due to anxiety regarding the rectal examination.
So this brings me to the more fundamental question; what is the role of cancer screening?
This may get a bit heavy but stay with me. All of the prostate cancer patients I see in clinic are adamant that prostate cancer screening is a must for all men. But screening is not only about improving the health and life of an individual but also protecting the whole screening community from unnecessary interventions and harm. There are thousands more men who are screened who do not have cancer.
So to attempt to explain the complexities of screening lets start at the beginning and answer the critical question –
What is the purpose of cancer screening and in particular prostate cancer screening?
One would naturally think it must be to detect cancers early. However in actual fact the goal of any cancer screening program must be to make you live longer. Some prostate cancers are so slow growing that you will die from other diseases well before your prostate cancer spreads and leads to your death. This sounds unbelievable as there is so much dread associated with the word ‘cancer’ but trust me on this one. Other cancers are highly aggressive and can take your life within years.
There is thus a massive spectrum in the severity of prostate cancer and all cancers are clearly not the same. We must strive for a cancer screening test that can identify the dangerous and lethal prostate cancers and also tells us which prostate cancer is an indolent one and can be watched or ignored. A good analogy here is to think about a 1 foot high fenced in area which represents your prostate. Imagine there are 3 types of prostate cancer inside the fence represented by a turtle, a hare and a dove. The turtle is the very slowing moving prostate cancer that will never escape your prostate and thus can be safely ignored. A cancer screening program should not identify these cancers or at least be able to tell us we can ignore them. The dove is the very aggressive prostate cancer that has in all likelihood already spread beyond the prostate. If we detect this cancer in the prostate with a screening test its immaterial. It’s simply too late to cure this cancer as it’s already flown from the prostate. Lastly, the hare represents the prostate cancer that has the potential to escape the fenced in area and become a lethal cancer but can be identified early using a screening program ie. before it can jump over the fence and escape. It is this cancer, if removed early, that will result in a life saved from screening. Get it?
So what can or should I do?
The best advice is to be body aware and involve your GP if there are any obstructive urinary symptoms or changes to your wellbeing. Don’t sit on things, or your prostate, and hope they go away. The next piece of advice is to focus on the modifiable risk factors for prostate cancer. These are maintaining a healthy weight range, regular exercise, maintaining a healthy diet and following the guidelines for alcohol consumption.
Prostate cancer is hormone driven and the more fat you have the more leptin you have to potentially cause prostate cancer.
Studies have demonstrated the association between increased prostate cancer and waist circumference1. High blood pressure has also been demonstrated to increase your risk of prostate cancer. Other analyses2 have explored the role of diets rich in tomatoes (source of lycopenes) which appear to have a modest role in preventing prostate cancer if copious amounts of raw tomatoes are eaten. The Mediterranean diet has captured a lot of media interest of late. It’s a diet full of leafy green vegetables, low red meat and dairy intake, high intake of legumes, nuts and wholegrain cereals.
Why is that so?
In a nutshell (pardon the pun) the Mediterranean diet is abundant in foods that may protect against prostate cancer (n-3 fatty acids and phytochemicals – lycopene, resveratrol and Vitamins E &C) and is associated with longevity and reduced cardiovascular and cancer mortality. Compared with many Western countries, Greece has lower prostate cancer mortality and Greek migrant men in Australia have retained their low risk for prostate cancer. Consumption of a traditional Mediterranean diet, rich in bioactive nutrients, may confer protection to Greek migrant men, and this dietary pattern offers a palatable alternative for prevention of this disease. At the end of the day, it’s hard to categorically conclude based on the evidence that following a Mediterranean diet will lower your chances of prostate cancer but nonetheless it is a healthy approach to eating. Several meta-analyses have concluded opposite findings, one3. where there is no benefit and a second4 study which did demonstrate a lower probability of dying from cancer.
- Effect of metabolic syndrome and its components on prostate cancer risk: Meta-analysis – K Esposito et al Journal of Endocrinological Investigation 2013.
- Increased dietary and circulating lycopene are associated with reduced prostate cancer risk: a systematic review and meta-analysis – J Rowles et al Prostate Cancer and Prostatic Diseases 2017
- Mediterranean dietary pattern and the risk of prostate cancer. A meta-analysis – S Cheng et al Medicine 2019
- Adherence to Mediterranean diet and risk of cancer: an updated systematic review and meta-analysis of observational studies – Lukas Schwingshackl et al Cancer Medicine 2015