Understanding prostate cancer in 9 questions

The prostate is a small chestnut-sized gland which forms part of a biological male’s internal sexual organs. It’s found directly below the bladder, just in front of the rectum and surrounds the upper section of the urethra (the tube your urine passes through). The prostate’s main job is to produce a portion of the semen that helps transport and protect your sperm after ejaculation. Prostate development and function is controlled by male sex hormones, with testosterone playing the most important role.

Cancer is caused by the uncontrolled division of cells, resulting in the growth of a tumour. Once the cancerous cells invade the surrounding tissue, it becomes what’s known as a ‘malignant tumour’. The cancer can advance when tumour cells travel via your blood or lymphatic system into other organs where they can form secondary tumours called ‘metastases’.

Many prostate tumours grow slowly. A prostate tumour may remain in its early stages for years, causing no health problems or pain. In this case, there is no immediate call for treatment.

Around half a million people in Europe are diagnosed with prostate cancer every year – making it the most common cancer in men, and accounting for 20% of all cancer diagnoses. ¹ The reason why some men develop prostate cancers while others don’t is unknown, but there are some factors that can increase the risk of developing the disease, including:

• Age: incidence of prostate cancer increases with age, with 66 years being the average age at diagnosis ²
• Family history: you have a substantially increased risk if a male relative has had prostate cancer ³ or if you carry a BRCA2 mutation ⁴
• Ethnicity: if you are of African descent, your risk is substantially increased ^5,6
• Lifestyle: obesity ⁷ and a high intake of processed meat ⁸ increase the risk of developing prostate cancer.

While targeted prevention is not possible, there is evidence that a healthy diet, regular exercise, and maintaining a healthy weight may reduce the risk of developing prostate cancer.

Prostate cancer rarely causes symptoms in its early stages. If you experience the following symptoms, it may indicate the presence of prostate cancer, but could also indicate benign prostate enlargement:

• Urinary problems, such as weak or intermittent flow
• Frequent urination
• Pain during urination
• Blood in the urine
• Blood in the semen or painful ejaculation

Two different examination methods are used to detect prostate cancer: a digital rectal examination and measure of the blood’s prostate-specific antigen (PSA) level. An increased PSA level is not necessarily anything to worry about – it often indicates benign prostate enlargement or insignificant inflammation –but in some cases, it might indicate the presence of prostate cancer.

If your PSA level or digital rectal examination detects anything abnormal, your doctor may recommend further testing such as an ultrasound, an MRI, or a tissue biopsy, to confirm whether the abnormality is cancer. If it is cancerous, a biopsy can be used to determine how quickly or slowly the cancer is likely to progress, and imaging tests can be used to understand whether the cancer has spread.

Multiple methods are used to determine how advanced and aggressive your cancer is. These methods include tumour staging and the TNM system and the Gleason score. Your PSA level may also be used in conjunction with these methods.

The tumour staging system is a way to measure how far in your body the cancer has spread. Prostate cancer is divided into four tumour (T) stages, each of which may be further broken down into substages.

This is a simplified version of the T stages:

• T1: A small tumour (within the prostate) that’s detectable via a tissue biopsy.
• T2: A slightly larger tumour (also within the prostate) that can be felt or seen by rectal exam or imaging.
• T3: The tumour has advanced locally beyond the prostate.
• T4: The tumour has spread to neighbouring or distant lymph nodes, or other parts of the body.

The TNM system refers to tumour, nodes and metastases. This system uses the ‘T’ staging system, as just described, in addition to scores to indicate whether the cancer has spread to the lymph nodes (N) and whether it has metastasised (M) to other parts of the body.

N is divided into:

• N0: Nearby lymph nodes are free of cancer cells
• N1: Cancer cells are present in the lymph nodes near the prostate

M is divided into:

• M0: The cancer has not spread to other parts of the body
• M1: The cancer has spread to other parts of the body

While the methods above describe how far the cancer has spread, the Gleason score tells you how the cancer is likely to behave. The Gleason score is determined by microscopic observation of your cancer cells, which are obtained via a biopsy. A low Gleason score (6 or below) is given to cells which are similar to healthy prostate tissue, whereas a high score (8-10) describes an aggressive cancer cell type. The score therefore indicates how slow or fast the tumour is likely to progress.

Treatment for prostate cancer is highly individual and will be guided by the stage of your tumour. For people diagnosed with early-stage (T1 or T2) prostate cancer, there are four main types of treatment to consider:

• Active surveillance can be applied to small, low-risk tumours. It involves regular PSA testing, digital rectal examinations, and (possibly) repeat prostate biopsies. If the tumour progresses and you decide to pursue more aggressive treatment, radiotherapy and surgery are the next step.
• Radiotherapy uses targeted radiation to damage your prostate cancer cells and stop them from dividing. There are several different types used to treat prostate cancer, including external beam radiotherapy and brachytherapy (a more specific form of internal radiation treatment).
• Radical prostatectomy refers to the surgical removal of the prostate gland. This option is for cancers limited to the prostate.
• High intensity focused ultrasound (HIFU) uses a probe to deliver ultrasound energy to the prostate through the rectum, which then heats and destroys cancer cells. HIFU is only appropriate for patients with localised prostate cancer. It is not as widely available as radiotherapy or prostatectomy.

If your cancer has spread into neighbouring organs or developed metastases (Stages T3 and T4), the prognosis may be less favourable, and a cure no longer possible. In this instance, treatment aims to delay disease progression and slow the growth of your prostate cancer. Options include:

• Hormone therapy, including androgen deprivation therapy (ADT), which is designed to reduce the amount of androgens your body produces (mainly testosterone and dihydrotestosterone). Administered by injection, tablets or surgery, by targeting the hormonal drivers of your prostate cancer, it is possible to slow and control disease progression for considerable periods of time.
• Chemotherapy, which is usually used in addition to hormone therapy. This approach uses anti-cancer drugs to kill cancerous cells and shrink or slow the growth of your tumour.
• Immunotherapy, which uses medicine to trigger an immune response so that your body can recognize and destroy its own cancer cells.
• PARP inhibitors, which work by stopping PARP enzymes from repairing the damaged DNA in your cancer cells and causing them to die. This treatment can be an effective way to slow and shrink your cancer, but is only appropriate for people with a specific mutation in their BRCA1/2 genes (these genes normally protect against the growth of cancer).

Starting any new course of treatment can be daunting. Your physician can inform, advise and guide you on the most appropriate course of action. There are many different elements to consider, including the stage of your disease, your age, health, and personal preferences.

Every type of treatment brings different benefits and risks. It is important to understand the implications of each. Your physician is there to answer any questions you might have and develop a treatment plan that is tailored to your individual diagnosis and needs