Kidney Cancer :: Prostate Cancer
Bladder Cancer :: Testicular Cancer
Prostate cancer develops in the prostate, a gland in the male reproductive system that helps make and store seminal fluid. Most prostate cancers are slow growing; however, there is a subgroup (about a third) of aggressive prostate cancers. The cancer cells may metastasize (spread) from the prostate to other parts of the body, particularly the bones and lymph nodes.
Usually prostate cancer does not cause symptoms early on and symptoms develop during later stages of the disease. This has led to prostate cancer screening, or case finding, using a PSA blood test and finger examination in an attempt to find prostate cancer earlier when it is more likely to be curable. The difficulty that has resulted from this approach is that because many cancers are slow growing they may not be lethal, particularly for those men with more pressing medical problems. The decision to proceed to treatment of prostate cancer is therefore a balancing act and needs to be considered carefully to manage the disease but avoid over-treatment.
Tests involved with prostate cancer treatment
Surgery is only offered to patients for the purpose of disease cure. This assessment is based on clinical tests that include the PSA, Gleason grade and rectal examination findings. Men with higher risk features may be recommended to undergo further scans to help determine whether disease has progressed out of the prostate or spread to other parts of the body (metastasized) which would make operative treatment inappropriate.
Digital Rectal Examination (DRE)
A gloved finger is inserted into the rectum to feel the condition of the prostate that lies close to the rectal wall. If an irregularity such as a lump is felt, further tests will be necessary to enable a more accurate diagnosis.
Prostate Specific Antigen (PSA) Test
A blood sample is taken to check for prostate specific antigen (PSA), which is produced by the prostate. As men get older the prostate gland grows and so the PSA is likely to rise. A high PSA result from several types of prostate disease. The level can be raised due to inflammation of the prostate (Prostatitis) and enlargement of the prostate gland (Benign Prostatic Hyperplasia or BPH) as well as prostate cancer.
PSA is a useful tool for diagnosing and monitoring prostate diseases, but further tests are required to confirm which condition is present.
Transrectal ultrasound guided biopsy (TRUS)
Trans Rectal Ultrasound Guided biopsies is discussed elsewhere, click here to find out more.
Staging and Grading
The tests performed are used to determine the stage of the prostate cancer. Biopsy specimens are analysed to find out how aggressive the cancer is. The staging system describes how far the cancer has spread within and/or beyond the prostate capsule and follows the T (tumour) N(node) M(metastasis) format.
||Reflects the growth of the original primary tumour
||The tumour is unable to be felt and is found by other means (at TURP or needle biopsy for a high PSA)
||The tumour can be felt but is contained within the prostate
||The tumour has extended out of the prostate into the surrounding fatty tissue
||The tumour has extended out of the prostate into local organs or the walls of the pelvis
||reflects whether lymph nodes distant to the prostate are involved with disease
||reflects whether other organs and tissues distant to the prostate are involved with disease
The Gleason Score indicates how aggressive the cancer is. The Gleason Score (or Sum) is given by a pathologist who inspects the appearances of the cancer cells under a microscope. The Gleason Score is actually made up of 2 numbers known as Gleason Grades. When a pathologist looks at the prostate cancer under the microscope, a number grade from 1 to 5 is assigned to the areas most representative of the cancer present (the primary Gleason Grade). A second number grade from 1 to 5 is given to the second most representative area within the cancer (The secondary Gleason Grade). These two numbers are added together to give the Gleason Score, the maximum Gleason Score is 10 and the minimum Gleason score is 2. The higher the score, the more aggressive the tumour is likely to be and this will impact on the likely success of treatment.
This scan assesses whether the cancer has spread to the bones. A small amount of radioactive material is injected into your arm, which is then absorbed by the cells within the bones. Your body will then be scanned an hour later to view the activity of the bones and ascertain whether the cancer has spread.
Magnetic Resonance Imaging detects anatomy on the basis of the way different tissues behave in a magnetic field. Dyes may be used to improve detail with these scans as well. This scan is useful to look for disease spread to the non-boney tissues not evaluated by the bonescan and may provide information about the extent of growth of the primary tumour as well (i.e. the T stage).
Treatment options for prostate cancer with intent to cure are primarily surgery or radiation therapy. Other treatments, such as hormonal therapy, chemotherapy, cryosurgery, and high intensity focused ultrasound (HIFU) also exist, depending on the clinical scenario and desired outcome. The age and underlying health of the man, the presence of spread, appearance under the microscope, and response of the cancer to initial treatment are important in determining the outcome of the disease. The decision whether or not to treat localized prostate cancer (a tumor that has not spread to areas other than the prostate) with curative intent is a patient trade-off between the expected beneficial and harmful effects in terms of patient survival and quality of life.
Radiation Therapy for Prostate Cancer
What is Radiation Therapy?
Radiation therapy uses high-energy rays to kill cancer cells using a machine called a ‘Linear Accelerator'. Damaging the cancer cells means that they cannot grow or multiply and so they die. Normal cells are also damaged in this procedure causing side effects but usually recover.
Radiation can be delivered in more than one way. In New Zealand the options are between External Beam Radiotherapy (EBRT) and Brachytherapy. EBRT involves energy rays generated by a machine outside the body which are focused on the target organ, in this case the prostate, using image guidance. The energy is broken down into small packets delivered every working day for a roughly 7-8 week period in an attempt to reduce side effects. Brachytherapy involves implanting radioactive seeds into the prostate under anaesthetic, which give off a set dose of radiation over a predictable period of time then stop working. The seeds remain in place permanently after this but have no ongoing effect.
Who gets Radiation Therapy?
Radiotherapy may be suitable for treatment with the intention of cure (for localized disease) or palliation (symptom relief for incurable advanced cancer).
The main choice for cure of localized prostate cancer (cancer that has not spread to other areas) is between operative removal of the prostate and radiotherapy in some form. As a general rule, younger men who are otherwise healthy will tend to opt for surgical treatment while for older men particularly with other medical conditions this may not be the safest option and radiation may be preferred. There have never been rigorous trials directly looking at the cancer cure rates between the two forms of treatment however comparisons suggest that results are likely to be fairly similar, perhaps slightly favouring surgical outcomes.
Before having radiation therapy a number of initial procedures need to be performed allowing doctors to specifically plan the best treatments for the type of cancer and the individual. This means that an accurate radiation dose to your cancer can be calculated while limiting the radiation to the surrounding areas such as the rectum.
What are the Side Effects?
The x-rays used during radiation therapy may damage normal body cells as well as cancer cells, although healthy cells usually recover from the damage. The incidence and severity of any side effects vary from patient to patient and may include
- Tiredness or fatigue
- Bladder irritation, cramps or painful urination/blood in the urine.
- Diarrhoea and Bowel Cramps.
- Proctitis or pain in the rectum/bleeding.
- A small increase in the risk of bowel cancer in the future (from 5.1 per 1000 to 10 per 1000 over 10 years)
A variety of measures can be taken to alleviate these symptoms
Radical prostatectomy is an operation which involves removal of the prostate and reconstruction of the urinary tract by attaching the bladder to the top of the urethra (outflow pipe). It is considered by many urologists and oncologists to be the 'gold standard' as it allows complete removal of the tumour when organ-confined, as well as accurate staging. It also allows confidence in interpreting the PSA level after treatment. If the PSA is undetectable there is no sign of cancer recurrence, if the PSA increases (as it may do for a small percentage of men) recurrence is detected on average at least 3-5 years before it otherwise would cause symptoms. This may allow salvage radiotherapy to be given as well, whereas men who have failed radiotherapy are rarely offered surgery because it tends to be detected later and the side effects of salvage surgery are much greater. Having said this however “the first choice is the best choice” and whether second line treatment is available should not be the main reason for choosing an operation. Finally, surgery corrects obstruction to the drainage of urine from the bladder caused by enlargement of the prostate. Despite these advantages direct comparisons between different types of treatment have never been made so it is not possible to say which treatment is “better” with certainty. The main disadvantages of radical prostatectomy are that it is a moderate sized operation and following surgery men may be troubled by incontinence (poor control of urine resulting in leakage) and erectile dysfunction.
Within the operation there are subtle modifications that may be made depending on the stage and grade of the tumour to try and offset some of these issues. For more advanced and higher grade but localized cancer, wider excision of the prostate (removing more of the surrounding tissues) and lymphadenectomy (removing lymph nodes which act as one of the first landing sites for spreading prostate cancer cells) may be performed.
For smaller and lower grade tumours the operation may be modified to leave the neurovascular bundles intact in an attempt to preserve erectile function. The nerves which control the erection mechanism run just outside the capsule of the prostate (on average 2-4mm away) behind the gland (at the 5 and 7 o’clock positions when looking towards the feet). Removal of these nerves almost always results in loss of erectile function. In selected cases it may be possible to preserve one or both of these nerves and thereby increases the chances of a return of erectile function either with or without medications such as Viagra, Cialis or Levitra.
Following open radical prostatectomy, men usually stay in hospital 3-4 days, have a drain for the first 24 hours and a catheter which remains in place for 10 days (i.e. they go home with it initially). The post–operative recovery period is around 6 weeks.
Radical prostatectomy has traditionally been performed as an open operation with an incision in the lower abdomen. Over the last 10 years there has been a significant shift in North America and Europe towards minimally invasive surgery in an attempt to reduce surgical side effects and speed post operative recovery.
Laparoscopic radical prostatectomy, using an optical scope and instruments placed via 5 small ports, takes longer to perform but the hospital stay is usually 2-3 days with a post-operative recovery period around 3-4 weeks.
What are the Side Effects?
Radical prostatectomy may cause a number of possible side effects.
During the operation, risks include bleeding, infection and adjacent organ (such as bowel or nerve) injury. Following an operation the long term side effects may include loss of urinary control (incontinence), loss of erections (impotence) and scarring at the point of reattachment of the bladder to the urethra.
Loss of both urinary control and erections should be expected initially. Urinary function returns over time with the great majority of men recovering to the point of no longer requiring pads without further treatments, however this may take some time (months). Regular pelvic floor exercises may help this process.
Recovery of erectile function is less predictable, depending on the number of nerves preserved and pre-existing level of sexual function. Although not firmly established as a standard of care, there has been a movement towards taking regular erectile medications such as Viagra, Cialis or Levitra following surgery to help with this process.
Pathology results and second line treatment
Many men consider the fact that removal of the prostate provides a pathological specimen and a definitive result as a key reason for deciding on surgical treatment. It provides clarity about the extent of disease and more information about prognosis (what the long term outcome will be).
In a small percentage of patients the tumour will extend up to the cut edge of the prostate, this is called a positive surgical margin. This happens because most prostate cancers arise in the outer part of the prostate gland. The more advanced the prostate cancer, the higher the chance of a positive surgical margin. Many men will be cured despite having a positive surgical margin however there is a greater risk of disease recurrence if this is present or with higher grade (Gleason 8 and above) and higher stage (T3) cancer found in the pathology specimen.
Men in this situation may be offered second line radiotherapy as either an adjuvant (given early after surgery with no evidence of recurrence) or salvage (given when PSA becomes and remains detectable during post-operative follow-up) therapy. The pros and cons of each approach should be considered carefully as currently it is not clear which is the most appropriate option. Adjuvant treatment may be a more effective cure as any remaining cells will be in their smallest numbers but risks over-treating (and perhaps causing side effects for) a significant number of men who would otherwise have remained PSA free and cured. Salvage treatment avoids over-treating those men who are cured but may be less effective in treating those men with recurrent disease. Trials are underway to settle this debate however information from them will not be available for several years yet.
Hormonal Therapy for prostate cancer.
The progression of prostate cancer is driven by hormones and especially by Testosterone, the male hormone. It has long been recognized that “starving” the cancer by blocking it’s supply of testosterone will slow down the rate of progression (but not cure the cancer).
The production of testosterone occurs within the testicles. Regulation of testosterone levels is controlled by a hormone released from the pituitary gland within the brain. This hormone (luteinizing hormone or LH) travels in the blood stream to the testicles. Blocking the supply of testosterone to cancer cells can therefore be achieved at several levels. The initial signal from the brain can be blocked, production of testosterone by the testicles can be blocked and the receptors on prostate cancer cells to which hormones attach can be blocked.
Originally hormonal therapy was achieved by surgical removal of the testicles. Bilateral orchidectomy is a quick and relatively minor procedure that may often be done as a day case operation. It involves an incision through the scrotum and is performed under general anaesthetic. The main risks are bleeding and infection.
More recently there has been a shift towards medical hormonal therapy. The mainstay of this is an injection that blocks the LH signals coming from the pituitary gland within the brain. The medications used are known as “LHRH agonists”. There are a number of different versions however they have similar effects and side effects and are administered by an injection given at regular intervals (usually once every 3-6 months).
A second form of medical hormonal therapy blocks the hormone receptors on cancer cells directly. This group of drugs is called the “Anti-androgens” and is given as tablets on a daily basis. Although there are some small differences in side effects they are generally similar in this regard as well as in effectiveness.
There are a number of other medications which may have effects on prostate cancer, but are used less frequently and later in the treatment course. Chemotherapy has a fairly small role in prostate cancer management compared with other cancers, however is being actively investigated in a number of medical research trials.
What are the Side Effects of Hormonal Therapy?
The side effects of hormonal therapy are generally due to testosterone deprivation of normal tissues rather than because of a reaction to the medicine. There are a number of different issues seen in this situation which are grouped together as the “Androgen Deprivation Syndrome”.
Symptoms are often compared to the female menopause (which results as normal oestrogen levels decrease). They can include hot flushes, fatigue, mood swings and sexual dysfunction (loss of libido and erections). Lack of testosterone may lead to loss of muscle mass and bone density (osteoparosis) as well as weight gain. There can be growth and tenderness of the breast tissue (gynaecomastia and mastodynia). Treatment may also be associated with changes in blood cholesterol levels and possibly increase the risk of heart disease.
In an attempt to reduce the side effects of treatment, having regular breaks from therapy, “Intermittent Androgen Deprivation”, may be an option for some people.
Who is suitable for Hormonal Therapy?
Hormonal therapy in general is used in two situations. Firstly it has become an important addition to radiotherapy (although not to surgery) as it has been shown to improve it’s effectiveness. Secondly, it is used for the treatment of metastatic prostate cancer (that has spread to tissues other than the prostate). It can be a very valuable palliative (relief giving) therapy and may also prevent some of the complications of spreading disease.
Hormonal treatment works for most people for a period of time (on average several years) but may eventually lose effectiveness. The timing and risks of treatment should be personalized to the individual depending on their situation.