Prostate cancer Flashcards
Define prostate cancer.
A malignant tumour of glandular origin, situated in the prostate.
How common is prostate cancer? Who is most affected?
- Second leading cause of cancer mortality in men in the US.
- Uncommon in men aged under 50 years.
- Median age of diagnosis is 66years,
What is the aetiology of prosate cancer?
Unknown but high fat diet and genetic factors have been suggested in the aetiology. Black men in US have highest incidence of prostate cancer of any ethnic group.
What are the risk factors for prostate cancer?
- Age >50yrs
- Black ethnicity, north American or northwest European descent
- Family history
- High levels of dietary fat - x1.6-1.9
- BRCA 2 gene
What are the presenting signs/symptoms of prostate cancer?
- Asymptomatic; raised PSA
- LUTS - obstruction (frequency/urgency/incontinence/nocturia) and voiding (hesitancy, poor stream, straining, long micturition, incomplete emptying, dribbling)
- Urinary retention / renal failure
- Abnormal DRE - normal prostate is walnut-sized
- Haematuria
- Lethargy, palpable lymph nodes, bone pain, weight loss, spinal cord compression (Mets) - could present as an old male not being able to walk
What is PSA? How does it change with age?
PSA is a serine protease that is produced by the prostate gland and secreted into the seminal fluid where it is involved in the liquefaction of the seminal coagulum. It is also found in blood either free or bound to plasma proteins.
PSA increases with age.
What is a normal PSA? What are the causes of RASIED PSA?
Normal PSA = 0-4 micrograms/L (ng/ml)
- Ageing
- BPH
- Urinary Retention
- Urine infection
- Catheterisation / instrumentation of urethra
- Prostate cancer - increase in PSA of 0.75 micrograms/L/year may be cancer
Not significant:
- Digital rectal examination
What invasive technique is used to diagnose prostate cancer?
- TRUS biopsy is used for TISSUE DIAGNOSIS (transrectal ultrasound guided biopsy)
- This should be done when PSA is >3micrograms/L
- 10-12 cores are taken
- Pathology reports on presence of intraepithelial neoplasia/carcinoma, Gleason score, % of each core that is positive, and invasion.
- MRI-TRUS detects clinically significant prostate cancer in a greater number of men compared with standard ultrasound-guided biopsy
Alternatives:
- Transperineal Biopsy
- Template Biopsy
- Saturation Biopsy
What is the grading system used for prostate cancer?
Gleason score - grades aggressivenes of the cancer cells; scores from 2 areas with the most cancer cells are added.
- Low risk 3+3
- High risk 5+5 and up
Grade - 2 is best prognosis and 10 the worst
Staging is done by TNM
What investigations would you do for prostate cancer?
- PSA (free and bound form total) - >4micrograms/L (but this needs to be correlated with age). % of free PSA may be useful e.g. if <10% of total it suggests an aggresive cancer may be present.
- Prostate biopsy (TRUS) - malignant cells detected in one or more biopsy specimens (assigned to grade group 1 to 5, max total 10)
- Testosterone - normal
- LFTs - normal
- FBC - normal except in metastatic disease
- Renal function - as above
- Bone scan - done if PSA >20micrograms/L
- X-rays - lytic or blastic lesions
- Pelvic CT scan - enlarged prostate +/- enlarged pelvic lymph nodes. Performed if the patient has clinical stage T3/T4 disease, or T1/T2 disease with a risk of lymph node involvement of >10% (e.g., assessed using the Partin nomogram)
Is there a screening programme for prostate cancer?
No - randomised 20-year study which combined regular DRE and PSA measurements showed no survival benefit between men who were screened and those who were not
What is the incidence of prostate cancer in each age group?
The general rule-of-thumb for age related incidence of prostate cancer is:
- 40 % over 40,
- 50 % over 50,
- 60 % over 60
- 80 % over 70.
By 90 almost all have neoplastic change in prostate gland.
Which zone do prostate cancers mostly arise?
Peripheral zone of the prostate
What is the histopathology of most prostate cancers?
95% are adenocarcinomas
Often multifocal - 70% lie in the peripheral zone
Where does prostate cancer spread first?
Lymphatic spread occurs first to the obturator nodes and local extra prostatic spread to the seminal vesicles is associated with distant disease.