Prostate Cancer Flashcards
Which cancer is the most common in men?
Prostate cancer is the most common cancer in men.
What are the risk factors for prostate cancer?
The key risk factors for prostate cancer are:
- Increasing age
- Family history
- Black African or Caribbean origin
- Tall stature
- Anabolic steroids
What hormones does prostate cancer rely on to grow?
Prostate cancer is almost always androgen-dependent, meaning they rely on androgen hormones (e.g., testosterone) to grow.
What is the most common form of prostate cancer?
What are the clinical features of prostate cancer?
Prostate cancer may be asymptomatic. It may also present with lower urinary tract symptoms (LUTS), similar to benign prostate hyperplasia. These symptoms include hesitancy, frequency, weak flow, terminal dribbling and nocturia.
Other symptoms include:
- Haematuria
- Erectile dysfunction
- Symptoms of advanced disease or metastasis (e.g. weight loss, bone pain or cauda equina syndrome)
Briefly describe prostate specific antigen
The epithelial cells of the prostate produce prostate-specific antigen (PSA). PSA is a glycoprotein that is secreted in the semen, with a small amount entering the blood. Its enzymatic activity helps thin the thick semen into a liquid consistency after ejaculation. It is specific to the prostate, meaning it is not produced anywhere else in the body. A raised level can be an indicator of prostate cancer.
Briefly describe the use of prostate specific antigen testing
Prostate-specific antigen testing may lead to the early detection of prostate cancer, potentially leading to effective treatment and preventing significant problems. However, research has failed to show that the benefits of using PSA for screening outweigh the risks. In the UK, men over 50 can request a PSA test if they would like one.
PSA testing is unreliable, with a high rate of false positives (75%) and false negatives (15%).
Other than prostate cancer, what else can cause elevate prostate specific antigen?
Common causes of a raised PSA are:
- Prostate cancer
- Benign prostatic hyperplasia
- Prostatitis
- Urinary tract infections
- Vigorous exercise (notably cycling)
- Recent ejaculation or prostate stimulation
What is the problem with PSA false positives?
False positives may lead to further investigations, including invasive prostate biopsies, which have complications and may be unnecessary. Additionally, it may lead to the unnecessary diagnosis and treatment of prostate cancer that would never have caused problems (the patient would have died of other causes before experiencing any adverse effects of the prostate cancer).
What is the problem with PSA false negatives?
False negatives may lead to false reassurance.
How does a benign prostate feel on examination?
A benign prostate feels smooth, symmetrical and slightly soft, with a maintained central sulcus (the dip in the middle between the right and left lobe). There may be generalised enlargement in prostatic hyperplasia.
How does an infected or inflammed prostate feel on examination?
An infected or inflamed prostate (prostatitis) may be enlarged, tender and warm.
How does a cancerous prostate feel on examination?
A cancerous prostate may feel firm or hard, asymmetrical, craggy or irregular, with loss of the central sulcus. There may be a hard nodule. Any of these features can indicate prostate cancer and warrant further investigation. In primary care, these findings require a two week wait urgent cancer referral to urology.
What is the first-line investigation for prostate cancer?
Multiparametric MRI of the prostate is now the usual first-line investigation for suspected localised prostate cancer.
What scale is used to assess prostate cancer following an MRI?
Likert scale.
Briefly describe the Likert scale
The results are reported on a Likert scale, scored as:
- 1: very low suspicion
- 2: low suspicion
- 3: equivocal
- 4: probable cancer
- 5: definite cancer
What score using the Likert scale would require a patient to undergo a biopsy of the prostate?
Patients with suspicious lesions on MRI (Likert 3 or more) will then go on to a biopsy (which can be several different forms).
If metastatic prostate cancer is suspected, what other investigations need to be ordered?
If metastatic disease is suspected, the patient will require further imaging. This includes:
- CT
- Bone isotope scans
Briefly describe the role of prostate biopsy in investigating prostate cancer
Prostate biopsy is the next step in establishing a diagnosis. The decision to perform a biopsy depends on the MRI findings (e.g., Likert 3 or above) and the clinical suspicion (i.e. examination and PSA level).
Prostate biopsy carries a risk of false-negative results if the biopsy misses the cancerous area. Multiple needles are used to take samples from different areas of the prostate. The MRI scan results can guide the biopsy to decide the best target for the needles.
There are two options for prostate biopsy:
- Transrectal ultrasound-guided biopsy (TRUS)
- Transperineal biopsy
Briefly differentiate between transrectal ultrasound-guided biopsy (TRUS) and transperineal biopsy
Transrectal ultrasound-guided biopsy involves an ultrasound probe inserted into the rectum, providing a good indicate of the size and shape of the prostate. Guided biopsies are taken through the wall of the rectum, into the prostate.
Transperineal biopsy involves needles inserted through the perineum. It is usually under local anaesthetic.
What are the risks of prostate biopsy?
The main risks of a prostate biopsy are:
- Pain (particularly lower abdominal, rectal or perineal pain)
- Bleeding (blood in the stools, urine or semen)
- Infection
- Urinary retention due to short term swelling of the prostate
- Erectile dysfunction (rare)
Briefly describe the use of isotope bone scanning
An isotope bone scan (also called a radionuclide scan or bone scintigraphy) can be used to look for bony metastasis.
A radioactive isotope is given by intravenous injection, followed by a short wait (2-3 hours) to allow the bones to take up the isotope. A gamma camera is used to take pictures of the entire skeleton. Metastatic bone lesions take up more of the isotope, making them stand out on the scan.
Briefly describe the Gleason Grading System
The Gleason grading system is based on the histology from the prostate biopsies. It is specific to prostate cancer and helps to determine what treatment is most appropriate. The greater the Gleason score, the more poorly differentiated the tumour is (the cells have mutated further from normal prostate tissue) and the worse the prognosis is. The tissue samples are graded 1 (closest to normal) to 5 (most abnormal).
The Gleason score will be made up of two numbers added together for the total score (for example, 3 + 4 = 7):
- The first number is the grade of the most prevalent pattern in the biopsy
- The second number is the grade of the second most prevalent pattern in the biopy
Briefly interpret the following Gleason scores:
- 6
- 7
- 8
A Gleason score of:
- 6 is considered low risk
- 7 is intermediate risk (3 + 4 is lower risk than 4 + 3)
- 8 or above is deemed to be high risk
