About Prostate Cancer

The prostate is an organ that secretes substances, like hormones, into the body. It’s found only in men and is about the size of a walnut. It lies just below the bladder and in front of the rectum. The prostate gland surrounds the tube through which urine flows and it produces fluid that makes up semen.

When something goes wrong with the turnover of cells in the body, a buildup of extra cells can form a mass, known as a growth or tumour. Growths can occur in the prostate and can be benign or malignant. Benign growths (such as benign prostatic hyperplasia) are rarely life threatening and can usually be removed.

Malignant growths can be dangerous and can spread and invade other parts of the body. Malignant growths can often be removed – but they sometimes grow back. South African men have a 1 in 24 lifetime risk of prostate cancer. In South Africa, prostate cancer is the leading cause of cancer in men (excluding non-melanoma skin cancer).

Whilst the actual cause of prostate cancer is unknown, several factors can increase your chance of being diagnosed. It’s mainly found in older men, has been shown to be the most prevalent form of cancer in white males in South Africa and is also becoming increasingly common in black men.

There are several signs and symptoms of prostate cancer and it’s important for men to be familiar with their bodies in order to identify problems early. In addition, prostate cancer screening can help detect prostate cancer before symptoms develop.

Risk factors

Although the exact cause of prostate cancer is unknown, there are certain aspects of life that may increase your chance of having prostate cancer or developing a more aggressive form of the disease. These include:

  • Age: Prostate cancer occurs more often in older men. After the age of 50, your risk is rapidly increased. Below the age of 45, prostate cancer is rare.
  • Family history: Genetic predisposition may increase prostate cancer risk. Men who have a first-degree relative (father or brother) with prostate cancer have twice the risk of developing the disease, and those with two first-degree relatives affected have a fivefold greater risk compared to men with no family history.
  • Diet: Having a healthy lifestyle can reduce your chance of developing many diseases. It’s been shown that a high fat intake (too much fast, snack or fried food, and baked goods), a high red meat intake (more than 300 grams of meat 4 times a week or more), and a diet low in vegetables is linked to a greater chance of having prostate cancer.
  • Other lifestyle factors: Obesity, lack of physical exercise and smoking increase chances of prostate cancer.
  • Alcohol intake: Having more than 2 standard sized alcoholic drinks per day is another risk factor for prostate cancer. A standard drink is 340ml of beer, 120ml of wine, 25ml of spirits or 50ml of sherry.
Important to note: It’s a common misconception that having a vasectomy increases your chance of developing prostate cancer – this isn’t true.

Diagnosis

There’s a lot of fear around prostate cancer diagnosis, but diagnosis is the first step in treating and managing the disease. Here are the various procedures available to move towards an accurate diagnosis:

Digital Rectal Examination
Once you’ve visited your doctor and they have a clear idea of your symptoms, they will likely perform a digital rectal examination, in order to feel the prostate through the wall of the rectum. This allows your doctor to determine whether there are any lumps or abnormalities in the prostate. A digital rectal examination is conducted by inserting a lubricated, gloved finger into the rectum

Other initial tests
During your first visit to the doctor you can also expect to give a urine sample in order to check for blood in the urine. Your doctor will also want to measure your Prostate Specific Antigen (PSA) level. This is done via a blood test.

Both the digital rectal examination and PSA test allow your doctor to identify whether there’s a problem with the prostate. If a problem is detected, further tests will need to be carried out to determine if cancer is present. The following tests may be performed:

Transrectal ultrasound (TRUS)

This involves the insertion of a probe into the rectum. Ultrasound waves are bounced off the prostate and used to form a picture called a sonogram. The sonogram will show up any abnormal areas on the prostate. This test is only used for sizing and guiding of the biopsy, and not for diagnosis of cancer.

Transrectal biopsy

This involves taking a sample of tissue from the prostate, using a needle and guided by the TRUS. The sample is viewed through a microscope by a pathologist, who will look for the presence of cancer cells. The tissue sample is obtained by the insertion of a thin needle through the rectum and into the prostate.

Prostate Specific Antigen (PSA)

Any time there’s talk of prostate cancer, you’ll probably hear people using the term ‘PSA’. When you first visit the doctor, they will take a blood test, which will show the level of Prostate Specific Antigen (PSA) in your blood. This result, along with other examinations,

will be used to find and diagnose prostate cancer.

PSA is a protein made by the prostate that helps keep semen in liquid form. A small amount of PSA enters the bloodstream and will show up on a blood test. PSA can be produced by both non-cancer and cancer in the prostate. Cancer cells usually produce more PSA than normal cells and therefore more PSA may enter the bloodstream in patients with prostate cancer and a higher level will be seen on a blood test.

Read More

Apart from prostate cancer there can be other reasons for a raised PSA level in the blood. These include:

  • An enlarged prostate (benign prostatic hyperplasia)
  • An inflamed prostate
  • A bladder infection (cystitis)
  • Recent ejaculation (24-48 hours prior to the PSA test)
  • A recent prostate biopsy (it’s advised to wait for a few weeks before doing a PSA test)
  • A recent digital rectal examination (doctors will take your blood before this examination)
  • Recent bicycle riding (though this has not been properly proven)

A raised PSA level doesn’t necessarily mean you have prostate cancer. Only about 1 in 4 men who have a raised PSA level turn out to have prostate cancer. Your doctor will need to interpret your PSA result based on your recent activity, age and previous medical history. They can then decide on whether to carry out further tests.

Understanding the stages

If you’ve been diagnosed with prostate cancer, you’ll need to have further tests to determine if the cancer has spread in the prostate or to other parts of the body. Staging is the term used to refer to the stage of the cancer and indicates the spread of the disease in the body. Staging is also used to plan treatment strategies.

In order to determine the stage of prostate cancer, the results of previous tests will be used (such as your PSA result) as well as results of other procedures, including:

  • A bone scan. This is used to check for cancer cells in the bone. A small amount of radioactive material is injected into your vein, travels through the bloodstream and collects in any abnormal cells in the bones. A scanner is used to look for collections of radioactive material.
  • MRI scan. This can demonstrate differences between normal and diseased parts of prostate tissue and assess whether cancer infiltrates the capsule of the prostate gland and/or other pelvic tissues outside of the prostate gland. An MRI scan also looks for lymph node involvement.
  • CT or CAT scan. This gives an assessment of the prostate gland position, its appearance and its relationship to other pelvic organs. It also helps plan radiation therapy.
  • Pelvic lymphadenectomy. This is a surgical procedure to remove the lymph node of the pelvis. Cells are then taken from the lymph node and viewed by a pathologist under a microscope to look for cancer cells.
  • Seminal vesicle biopsy. A needle is used to remove fluid from the seminal vesicle, which makes semen. The fluid is viewed by a pathologist under a microscope to look for the presence of cancer cells.

The most widely used staging system for prostate cancer is the American Joint Committee on Cancer (AJCC) TNM system.

The TNM system for prostate cancer is based on 5 key pieces of information:

  1. The extent of the primary tumour (T1 to T4 category)
  2. Whether the cancer has spread to nearby lymph nodes (N0 to N1 category)
  3. The absence or presence of distant metastasis (M0 to M1 category)
  4. The PSA level at the time of diagnosis
  5. The Gleason score

There are 2 types of staging for prostate cancer:

The clinical stage

The clinical stage is your doctor’s best estimate of the extent of your disease, based on the results of the physical exam (including DRE), laboratory tests, prostate biopsy, and any imaging tests you’ve had

The pathologic stage

The pathologic stage, which is based on the surgery and examination of the removed tissue

T categories (clinical)
There are 4 categories for describing the local extent of a prostate tumour, ranging from T1 to T4. Most of these have subcategories as well.

T1: Your doctor can’t feel the tumor or see it with imaging such as trans-rectal ultrasound.

  • T1a: Cancer is found incidentally (by accident) during a transurethral resection of the prostate (TURP) that was done for benign prostatic hyperplasia (BPH). Cancer is in no more than 5% of the tissue removed
  • T1b: Cancer is found during a TURP but is in more than 5% of the tissue removed
  • T1c: Cancer is found by needle biopsy that was done because of an increased PSA

T2: Your doctor can feel the cancer with a digital rectal exam (DRE) or see it with imaging such as trans-rectal ultrasound, but it still appears to be confined to the prostate gland.

T2a: The cancer is in one half or less of only one side (left or right) of your prostate
T2b: The cancer is in more than half of only one side (left or right) of your prostate
T2c: The cancer is in both sides of your prostate

T3: The cancer has grown outside your prostate and may have grown into the seminal vesicles

  • T3a: The cancer extends outside the prostate but not to the seminal vesicles
  • T3b: The cancer has spread to the seminal vesicles
T4: The cancer has grown into tissues next to your prostate (other than the seminal vesicles), such as the urethral sphincter, the rectum, the bladder, and/or the wall of the pelvis.

N categories
N categories describe whether the cancer has spread to nearby (regional) lymph nodes

  • NX: Nearby lymph nodes were not assessed
  • N0: The cancer has not spread to any nearby lymph nodes
  • N1: The cancer has spread to one or more nearby lymph nodes

M categories
M categories describe whether the cancer has spread to distant parts of the body. The most common sites of prostate cancer spread are to the bones and to distant lymph nodes, although it can also spread to other organs, such as the lungs and liver.

M0: The cancer has not spread past nearby lymph nodes
M1: The cancer has spread beyond the nearby lymph nodes
M1a: The cancer has spread to distant (outside of the pelvis) lymph nodes
M1b: The cancer has spread to the bones
M1c: The cancer has spread to other organs such as lungs, liver, or brain (with or without spread to the bones).

Stage grouping
Once the T, N, and M categories have been determined, this information is combined, along with the Gleason score and PSA level, in a process called stage grouping. If the Gleason score or PSA results aren’t available, the stage can be based on the T, N, and M categories. The overall stage is expressed in Roman numerals from I (the least advanced) to IV (the most advanced). This is done to help determine treatment options and the outlook for survival or cure (prognosis).

Stage I: One of the following applies:
T1, N0, M0, Gleason score 6 or less, PSA less than 10: The doctor can’t feel the tumour or see it with an imaging test such as trans-rectal ultrasound (it was either found during a transurethral resection or was diagnosed by needle biopsy done for a high PSA) [T1]. The cancer is still within the prostate and has not spread to nearby lymph nodes [N0] or elsewhere in the body [M0]. The Gleason score is 6 or less and the PSA level is less than 10.

OR

T2a, N0, M0, Gleason score 6 or less, PSA less than 10: The tumour can be felt by digital rectal exam or seen with imaging such as trans-rectal ultrasound and is in one half or less of only one side (left or right) of the prostate [T2a]. The cancer is still within the prostate and has not spread to nearby lymph nodes [N0] or elsewhere in the body [M0]. The Gleason score is 6 or less and the PSA level is less than 10.

Stage IIA: One of the following applies:
T1, N0, M0, Gleason score of 7, PSA less than 20: The doctor can’t feel the tumour or see it with imaging such as trans-rectal ultrasound (it was either found during a transurethral resection or was diagnosed by needle biopsy done for a high PSA level) [T1]. The cancer has not spread to nearby lymph nodes [N0] or elsewhere in the body [M0]. The tumour has a Gleason score of 7. The PSA level is less than 20.

OR

T1, N0, M0, Gleason score of 6 or less, PSA at least 10 but less than 20: The doctor can’t feel the tumour or see it with imaging such as trans-rectal ultrasound (it was either found during a transurethral resection or was diagnosed by needle biopsy done for a high PSA) [T1]. The cancer has not spread to nearby lymph nodes [N0] or elsewhere in the body [M0]. The tumour has a Gleason score of 6 or less. The PSA level is at least 10 but less than 20.

OR

T2a or T2b, N0, M0, Gleason score of 7 or less, PSA less than 20: The tumour can be felt by digital rectal exam or seen with imaging such as trans-rectal ultrasound and is in only one side of the prostate [T2a or T2b]. The cancer has not spread to nearby lymph nodes [N0] or elsewhere in the body [M0]. It has a Gleason score of 7 or less. The PSA level is less than 20.

Stage IIB: One of the following applies:
T2c, N0, M0, any Gleason score, any PSA: The tumour can be felt by digital rectal exam or seen with imaging such as trans-rectal ultrasound and is in both sides of the prostate [T2c]. The cancer has not spread to nearby lymph nodes [N0] or elsewhere in the body [M0]. The tumour can have any Gleason score and the PSA can be any value.

OR

T1 or T2, N0, M0, any Gleason score, PSA of 20 or more: The cancer has not yet spread outside the prostate. It may (or may not) be felt by digital rectal exam or seen with imaging such as trans-rectal ultrasound [T1 or T2].

The cancer has not spread to nearby lymph nodes [N0] or elsewhere in the body [M0]. The tumour can have any Gleason score. The PSA level is at least 20.

OR

T1 or T2, N0, M0, Gleason score of 8 or higher, any PSA: The cancer has not yet spread outside the prostate. It may (or may not) be felt by digital rectal exam or seen with imaging such as trans-rectal ultrasound [T1 or T2]. The cancer has not spread to nearby lymph nodes [N0] or elsewhere in the body [M0]. The Gleason score is 8 or higher. The PSA can be any value.

Stage III:
T3, N0, M0, any Gleason score, any PSA: The cancer has grown outside the prostate and may have spread to the seminal vesicles [T3], but it has not spread to nearby lymph nodes [N0] or elsewhere in the body [M0]. The tumour can have any Gleason score and the PSA can be any value.

Stage IV: One of the following applies:
T4, N0, M0, any Gleason score, any PSA: The cancer has grown into tissues next to the prostate (other than the seminal vesicles), such as the urethral sphincter rectum, bladder, and/or the wall of the pelvis [T4]. The cancer has not spread to nearby lymph nodes [N0] or elsewhere in the body [M0]. The tumour can have any Gleason score and the PSA can be any value.

OR

Any T, N1, M0, any Gleason score, any PSA: The tumour may or may not be growing into tissues near the prostate [any T]. The cancer has spread to nearby lymph nodes [N1] but has not spread elsewhere in the body [M0]. The tumour can have any Gleason score and the PSA can be any value.

OR

Any T, any N, M1, any Gleason score, any PSA: The cancer may or may not be growing into tissues near the prostate [any T] and may or may not have spread to nearby lymph nodes [any N]. It has spread to other, more distant sites in the body [M1]. The tumour can have any Gleason score and the PSA can be any value.

Risk stratification
Risk stratification is performed taking into account all of the above factors. This allows for you and your doctor to plan your treatment and assess possible outcomes with long-term prognosis.

Very low risk disease:

  • Clinical stage is T1c
  • Gleason score is 2-6
  • PSA is less than 10 ng/ml
  • Fewer than 3 biopsy cores positive, less than 50% of cancer in each core
  • PSA density <0.15ng/mL/g
Read More

Low risk disease:

  • T1 – T2a
  • Gleason score 2-6
  • PSA is less than 10 ng/ml

Intermediate risk disease:

  • Clinical stage is T2b – T2c or
  • Gleason score is 7 or
  • PSA is 10-20 ng/ml

High risk disease:

  • Clinical stage is T3a or
  • Gleason score is 8 -10 or
  • PSA is 20 ng/ml or above

Locally advanced: Very high risk disease

  • T3b-T4
  • Primary Gleason pattern 5 or
  • More than 4 cores with Gleason

Metastatic disease: Any T, Any N, M1
Once disease becomes M1 (metastatic) it progresses, despite therapy. The goals of treatment focus on slowing disease progression, improving quality of life and increasing survival time. Due to advances in research and development there are now newer therapies being made available, that have been shown to slow the progression of the metastatic prostate cancer, including Castration-Resistant Prostate Cancer (CRPC), and extend patient survival.

What is Castration-Resistant Prostate Cancer (CRPC)?
The majority of prostate cancer cells require the presence of testosterone hormones for stimulation of their growth. Castration is therefore one of treatment methods to control high risk, advanced or metastatic prostate cancer.

Prostate cancer however, may contain cells that are initially insensitive or develop resistance to castration. With time these cells predominate and the cancer continues its growth despite the absence of testosterone. This stage of cancer growth is called castrate resistant.

The term actually describes the fact that the prostate cancer is continuing to grow despite castrate levels of testosterone.

Due to advances in research and development, there are now newer therapies being made available, that have been shown to slow the progression of the CRPC and extend patient survival.