What is prostate cancer?
Cancer is the uncontrolled growth of cells within the body. Usually, all of our cells have a specific lifespan of days to years that is genetically programmed in our DNA. When our DNA becomes damaged, either through the aging process, exposure to toxins such as radiation or chemicals or through inherited genes, some cells do not die a natural death but continue to grow. As they do, they form new cells with the same genetic misinformation. These extra cells may form masses or tumours that can be either malignant or benign. A benign tumour is a tumour that does not invade the surrounding tissue or spread around the body and stays in one place. A malignant tumour invades the surrounding tissue or spreads via the blood or lymph networks and affects other cells and organs.
Not all prostate growth is malignant. Benign prostate hyperplasia, or enlargement of the prostate, affects about 50 percent of men between the ages of 50 and 60 and up to 90 percent of men aged 80 and above. Treatments for benign prostate hyperplasia are primarily aimed at slowing its rate of growth and treating symptoms. It is important to mention that benign prostate hyperplasia (BPH) is not linked to cancer and does not increase prostate cancer risk; however, BPH and prostate cancer symptoms can be very similar.
Prostate cancer only affects males. The prostate gland is necessary for semen production and is found just below the bladder, wrapped around the urethra which carries urine and sperm out of the penis. A normal prostate gland is approximately the size of a walnut.Â
Prostate cancer is the second most common form of cancer in the world among men. Most prostate cancer is caught in early stages before the prostate begins to enlarge. Some prostate cancers are extremely slow-growing and do not require treatment.
Are there different types of prostate cancer?
There are various forms of prostate cancer and your medical notes may be difficult to understand. Most specific types are based upon the location of abnormal cells.
Acinar adenocarcinoma
Adenocarcinomas develop in the cells that line the inside of the prostate gland and are the most common type of prostate cancer.
Ductal adenocarcinom
Ductal adenocarcinoma starts in the cells that line the ducts (tubes) of the prostate gland. This type of prostate cancer grows and spreads at a more rapid rate than acinar adenocarcinoma.
Squamous cell cancer
Squamous cells line most of the body’s organs. This type of cell grows and spreads more quickly than prostate adenocarcinomas.
Small cell prostate cancer
Like squamous cell cancer, small cell cancer is named according to the cell type that continues to multiply, creating similarly long-lived copies of itself. Small cells grow and spread more quickly than prostate adenocarcinoma types.
What are prostate cancer symptoms?
If you are reading this page, you may have been diagnosed with an early stage of prostate cancer on the basis of a blood test result called a PSA. If your diagnosis is the result of a rectal exam and PSA test carried out in response to the presence of one or more of the below-listed symptoms, then your prostate cancer has reached a later stage; however, a slow-growing tumour can respond extremely well to a single round of treatment, even with a later diagnosis.
Symptoms usually occur when the prostate has grown and begins to cause narrowing of the urethra. These symptoms are:
An urge to urinate more regularly or urgently, often multiple times during the night
Difficulty starting to urinate or taking a long time to finish urinating
A weaker urine flow than usual
The feeling that your bladder is not empty
Dribbling urine
Pain when urinating or ejaculating
Can I prevent prostate cancer?
No-one is sure how prostate cancer begins. Some factors might increase the risk of developing it, such as age (50 years and over), race (black males have a one in four chance of developing prostate cancer) and family history (father or brother with prostate cancer).Â
The best way to prevent prostate cancer developing into a later stage is for all men to begin routine screening from the age of 50 years and to be aware of the symptoms and family history relating to the disease. For those with a family history of prostate cancer, screening should begin from the age of 40 years.
How is prostate cancer diagnosed?
The diagnosis of prostate cancer and its treatment also depends on whether the cancer cells have spread or not. When contained within the prostate gland this is considered a localised cancer. If the cancer cells are found just outside of the prostate this is called locally advanced. Where cancer cells have travelled through the blood or lymph vessels and have reached other parts of the body from the prostate, this is known as advanced prostate cancer.
Upon the detection of higher levels of PSA in a blood sample, you should be invited for a digital rectal examination (DRE) where your GP or urologist will feel for any bumps or lumps on the prostate wall via the rectum. If nothing is felt you will probably be asked to repeat the PSA test in a week or two. If any abnormalities are felt during a DRE, you will normally be sent for a prostate biopsy. A prostate biopsy will require a local anaesthetic, light sedation or a spinal anaesthetic. You will be asked to lie on your side and draw up your knees. The doctor uses an ultrasound to view the prostate via the rectum and a series of thin, hollow needles extract suspect areas of tissue from the prostate. The procedure usually takes less than 10 minutes
The cells in the biopsy help to determine the Gleason Score. Urologists refer to the Gleason Score to determine how benign or aggressive a type of prostate cancer is.Â
The Gleason score issues points (1-5) for tissue taken from a prostate biopsy. Scores under 3 usually describe healthy prostate cells. Scores of three indicate that certain cells are dissimilar to healthy prostate cells and may be cancer cells. Scores of 4 and 5 are nearly always indicative of prostate cancer.
However, abnormal cells are rarely spread equally in any tissue sample and the Gleason Score solves this problem by grading the two most represented abnormal cell types. Primary grade cells make up the majority of the cancer cells in a tissue sample. Secondary grade cells refer to the second most common type of cancer cell in that sample.
This means that a Gleason Score of 2+3=5 shows that the majority of the tissue is grade 2 with cells that are extremely similar to healthy prostate cells and the second most common cell type is grade 3, the cells of which look a little unusual and may be cancerous. If there is only one type of cell present, this is counted twice.
Gleason Scores most commonly range between 6 and 10. The higher the Gleason Score, the more likely that cancer will grow and spread quickly. However, the Gleason Score is not fail-safe as it depends on tiny amounts of tissue. These tiny samples may not represent the entire gland. This is why the next step is usually an MRI. In addition, Gleason Score results sometimes seem much worse to a patient than they actually are. A Gleason Score of 6 seems quite frightening to a non-professional, but may be the result of 3+3=6 and represent primarily normal tissue with a small amount of very slow-growing cancerous cells.
Urologists are now looking for ways to grade prostate cancer that are easier for non-medical professionals to understand. Prostate Grade Groups are becoming more common. These categorize prostate cancer into 5 different groups:
Grade Group 1 = Gleason 1 - 6
Grade Group 2 = Gleason 3+4=7
Grade Group 3 = Gleason 4+3=7
Grade Group 4 = Gleason 8
Grade Group 5 = Gleason 9-10
Depending on the type of prostate cancer that is diagnosed, further tests are then planned. These include blood tests together with CT or MRI or bone density scans that can indicate whether cancer cells have spread into other areas.
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