Prostate cancer is the most common cancer diagnosed in Australia, and the third most common cause of cancer death. Around 17,000 new cases are diagnosed each year in Australia. As many men die from prostate cancer each year as women from breast cancer (about 3000).
What are the symptoms of prostate cancer?
As men get older the prostate can enlarge, compressing the urethra and making it difficult to pass urine. These men may develop symptoms such as a weak urinary stream, waking up at night to urinate, or being unable to defer urination when the urge arises. This very common condition is called benign prostatic hyperplasia (BPH) and is NOT cancer.
Prostate cancer rarely presents with any symptoms. When symptoms do occur, this usually indicates locally advanced or metastatic disease. These symptoms can include difficulty urinating, blood in the urine or semen, pain in the lower back or hips, or unexplained weight loss.
What are the risk factors for prostate cancer?
As men get older, their risk of developing prostate cancer increases. By age seventy-five, 1 in 7 men will be diagnosed with prostate cancer.
Men with a family history of prostate cancer have a higher risk of developing the disease themselves. The risk of prostate cancer, compared to the regular population, doubles when a brother or father has been diagnosed. This risk increases further if multiple relatives have been affected, if these relatives were younger when they were diagnosed, or if a female relative has breast or ovarian cancer.
Is there anything I can do to reduce my risk of prostate cancer?
A number of dietary supplements and medications have been thoroughly investigated for their potential role in preventing prostate cancer. All of these studies have been negative. In particular, there exists no evidence that selenium, Vitamin E, Vitamin C or lycopene reduce the risk of prostate cancer.
Anatomy of the prostate
The prostate is a small gland that sits beneath the bladder in men and produces much of the fluid that forms the semen.
Prostate cancer develops when abnormal cells in the prostate start to grow in an uncoordinated way. This cancer typically grows very slowly, although this is not always the case.
How do we diagnose prostate cancer?
Prostate cancer is confirmed by performing a biopsy. This involves using a special needle to take small pieces of tissue from different parts of the prostate. A pathologist examines this tissue to check for the changes associated with cancer and to determine how aggressive it is. Urologists perform prostate biopsy either through a transrectal or transperineal approach.
The decision to perform a biopsy is based upon the patient’s likelihood of having prostate cancer. This takes into account the result of the PSA blood test, any abnormalities noticed on finger examination of the prostate, the results of MRI, and whether the patient has a family history of prostate cancer.
What is PSA?
Prostate-specific antigen (PSA) is a chemical produced by prostate cells. It supports sperm by helping keep semen in a liquid state. Whilst normally secreted into the semen, PSA can backflow into the bloodstream and be measured using a blood test.
The PSA level may be raised for many reasons. These include:
- Prostate cancer
- Benign enlargement of the prostate
- Infection in the urine
- Inflammation of the prostate
- Operations on the urinary tract, such as cystoscopy to look into the bladder
- Recent intercourse and ejaculation
- External pressure on the prostate, for example from a bicycle seat after a long ride
PSA levels can fluctuate over time and vary from person to person. A man with significant cancer may have a normal PSA and, in the same way, a man who does not have prostate cancer may have a raised PSA.
PSA “density” measures the PSA level relative to the volume of the prostate. It helps clarify the significance of an elevated PSA in a men with enlarged prostates. A PSA density of > 0.15 carries an increased risk of prostate cancer.
The “free/total PSA ratio” is another refinement that can help assess risk. Men with prostate cancer have a greater fraction of PSA that is bound to other proteins in the blood, meaning they have a lower “free” PSA level. Those with a free/total ratio < 0.1 have a 56% chance of having prostate cancer. Men with a ratio > 0.25 have only an 8% chance of harbouring the disease.
Multiparametric MRI of the prostate
MRI (magnetic resonance imaging) can detect areas suspicious for prostate cancer, thereby allowing a more precise prostate biopsy.
MRI can also show whether cancer has spread locally, outside the prostate gland. This allows the surgeon to tailor his or her operation to maximise cancer control while still, if possible, preserving the tissues needed for erections and continence.
PET PSMA scan
PSMA can effectively detect recurrent or metastatic prostate cancer. Many surgeons now use PET PSMA instead of bone scans when staging their high-risk patients.
Grading and Staging Prostate Cancer
The combination of biopsy and imaging tests help determine the grade and stage of cancer.
“Grade” measures cancer aggressiveness. A pathologist classifies grade based on the appearance of tissue obtained from biopsy or prostatectomy. For the last fifty years, the Gleason grading system has classified prostate cancer from a score of 6 (least aggressive) to 10 (most aggressive). In 2016 the more intuitive ISUP (International Society of Urologic Pathology) score was introduced, grading cancer from 1 (least aggressive) to 5 (most aggressive).
“Stage” describes the amount of cancer present and whether it has spread beyond the prostate. When cancer is confined to the prostate gland we call it “localised” prostate cancer. If cancer has spread outside the gland to nearby structures such as the seminal vesicles, bladder or rectum, we call it “locally advanced” prostate cancer. “Metastatic” refers to prostate cancer that has spread to the lymph glands, bones, lungs, or liver.
We can combine this information to stratify patients into groups based on the risk of their cancer coming back after treatment. Patients are considered Low Risk if they have Gleason grade 6 cancer (ISUP Grade 1), PSA < 10 ng/mL, and tumour in no more than one half of one lobe of the prostate on finger examination. If the Gleason score is 7 (ISUP grade 2 or 3), PSA between 10 and 20 ng/mL, or the tumour encompasses more than half of one lobe, but not both lobes, then the patient is at Intermediate Risk of cancer recurrence. High-Risk patients have a PSA > 20 ng/mL, Gleason score between 8 and 10 (ISUP grade 4 and 5), or cancer in both lobes of the prostate.
Active Surveillance for Prostate Cancer
We offer active surveillance to men whose cancer has a low risk of spreading beyond the prostate.
Men are carefully observed with regular blood tests, imaging and clinical examination until they develop pre-determined triggers for curative treatment. The goal is to minimize the side effects of treatment, without compromising survival, in men with a long life expectancy who can be cured with surgery or radiotherapy.
Active surveillance differs from “watchful waiting,” which is a palliative approach to manage symptoms in men in whom the risks of treatment outweigh the potential benefits. The goal of watchful waiting is to minimize treatment-related side effects in older men who are likely to pass away from other medical problems.
What is the rationale for active surveillance?
- Many men with a diagnosis of prostate cancer may never develop symptoms that affect their quality of life, or disease that affects their survival
- Active surveillance avoids the potential long-term side effects of treatment, such as the impotence or incontinence
- Surveillance may have less of a psychological impact than curative but potentially unnecessary treatment
Am I a candidate for active surveillance?
Forty-five percent of men with PSA-detected cancer will be candidates for some sort of deferred management.
Features of low-risk prostate cancer include:
- Prostate biopsy showing only Gleason 3+3=6 disease (ISUP Grade Group 1)
- Biopsies with only 2 to 3 samples that are positive for Grade Group 1 cancer and each sample has <50% cancer involvement
- Blood PSA levels less than 10 ng/mL
- PSA density less than 0.15 ng/mL/mL
Several different surveillance protocols have been studied. Depending on a patient’s individual circumstances, a specialist may recommend active surveillance even if they do not strictly meet the above criteria. For example, a doctor may recommend surveillance to a man in his late 70’s with low-volume Gleason 3+4=7 (Grade Group 2) cancer.
If I am on active surveillance, does that mean I don’t need to worry about my cancer?
All men who embark on active surveillance must be willing to comply with regular ongoing follow-up due to the risk of developing aggressive cancer during surveillance. This is especially important in younger men with a long life expectancy.
Why do I need another biopsy?
Sometimes the initial biopsy misses an area of high-risk disease. We, therefore, perform a repeat biopsy, called a confirmatory biopsy, within 12 months to minimize the risk of missing these more aggressive cancers.
What are the triggers for active treatment?
Triggers for active treatment should be tailored to the circumstances of each patient and discussed prior to embarking on active surveillance. These triggers may include:
- A rapidly-rising PSA level
- Repeat biopsy with an increase in Grade Group or number of positive cores
- New abnormalities on digital rectal examination
- Patient choice
Radical prostatectomy involves removal of the prostate, seminal vesicles and, in many cases, the pelvic lymph nodes. This operation, now commonly performed through a robotic approach, aims to eradicate localised prostate cancer while preserving continence and, if possible, erectile function. It is suitable for men who have a life expectancy of greater than ten years.
Surgery has not been shown to improve survival in men with low volume, low risk (ISUP Group 1) prostate cancer. These men are better managed with active surveillance, with a plan to undertake surgery or radiotherapy if more aggressive disease develops. Intermediate risk cancers, however, clearly benefit from surgery, with improved overall and cancer-specific survival.
In high-risk or locally-advanced disease, we can combine radical prostatectomy with radiotherapy and androgen deprivation therapy (ADT) to maximise cancer control and delay time to disease progression. These men can achieve increased disease-specific survival through this multimodality approach.
As this is a surgical website, the discussion of radiotherapy shall remain brief. We recommend that interested patients seek the opinion of an experienced radiation oncologist.
Radiotherapy is an established alternative to surgery, particularly in men in whom surgery may not be appropriate. It has a role in multimodality treatment, and also in the salvage setting when cancer returns after prostatectomy. Surgery is still a curative option in situations where prior radiotherapy has failed, although in this setting the functional outcomes are worse.
How does radiotherapy work?
Radiotherapy uses high-energy radiation to cause fatal damage to cancer cells. This radiation is either produced in a machine called a linear accelerator and directed towards the prostate in a beam, called external beam radiotherapy (EBRT), or emitted from radioactive seeds injected directly into the prostate, called brachytherapy.
Prostate cancer cells require the male hormone testosterone to grow. Androgen deprivation therapy (ADT) involves reducing the level of testosterone in the blood through a series of injections, usually given every three months, thereby slowing cancer growth.
Radiation oncologists will often give a short course of ADT with radiotherapy as part of curative treatment for localised disease. With metastatic disease, the goal shifts from cure to control and ADT is able to contain cancer for months and often years.