Prostate Flashcards
Median age for prostate cancer:
70 years
Etiology of prostate cancer
Race
- African American males have a 60% higher incidence rate compared to caucasian males
- More common in western worlds compared to Asia
Family history
- The relative risk if affected brothers: 3.4
- The relative risk of affected fathers: 2.2
- Men with a family history of prostate cancer typically present at a younger age
Age
- <44 years incidence approaches 0
- 45-54 years incidence: 8.6%
- 55-64 years incidence: 28%
- 75-74 years incidence: 36.1%
- 74-84 years incidence: 22.0%
Diet
- A high-fat diet and red meat may increase the risk
- Soy, vitamin A and betacarotene may be protective
Hormonal influence
- Low testosterone reduces the risk
Genetics
- Hereditary prostate cancer accounts for approximately 10% of all cancer cases
- Possible genetic hypothesis include x-linked or recessive inheritance
Local spread of prostate cancer
- Extension through the prostatic capsule
- Seminal vesicle invasion
- Bladder invasion
- Rectal invasion
Lymph spread from the prostate
- periprostatic and obturator nodes
- external iliac, hypogastric, common iliac, and periaortic nodes
7% of patients have involvement of presacral nodes with no evidence of external iliac and hypogastric nodes
5-25% of patients have metastases to para-aortic nodes.
The natural history of prostate cancer
Untreated prostate cancer can lead to a myriad of problems:
- obstructive &/or irritative urinary symptoms
- hematuria (blood in the urine) or hematospermia (presence of blood in the sperm)
- rectal pain or bleeding
- painful bone metastasis
- neurological pain or weakness from compressive bone or soft tissue metastasis
- lower extremity swelling and edema from pelvic adenopathy
Cell classification for prostate cancer
- 95% are adenocarcinoma
- neuroendocrine and ductal carcinomas rarely occur
Location of prostate cancer
Peripheral zone tumours account for 80-85% of all tumours.
Transition zone tumours account for 10-15% of all tumours. Site of origin for benign prostate hyperplasia.
Central zone tumoours account for 5-10% of all tumours
Apex tumours account for 50-80% of all tumours
Gleason pattern 1
- Well-differentiated
- Uniform epithelium
- Oval nuclei
- Pale cytoplasm and rare mitotic figures
* not really used Gleeson score starts at 3
Gleason pattern 2
- well-differentiated glandular pattern
- more intervening stroma between glands
* not really used Gleason score starts at 3
Gleason pattern 3
- Moderately differentiated glandular pattern
- Distinctly infiltrative margins
Gleason pattern 4
- Poorly differentiated glandular pattern
- Irregular masses of neoplastic glands
Gleason pattern 5
- Poorly differentiated/anaplastic glandular pattern
- Only occasional gland formation
- Sheets of tumour cells, mitosis, cellular atypia
Gleason score
The combination of the two most common patterns observed in the tissue sample.
Ex.
3+4 = 7
4+3 = 7 but worse because 4 is more common then three
Signs and symptoms of prostate cancer
Most asymptomatic at presentation usually detected with screening PSA or DRE
Possible urinary or rectal function
DRE
Digital rectal exam
Superficial and deep palpation is indicated
Firmness or hardness is consistent with cancer
Cysts are typically smooth, small and mobile
Rectal mass will require further evaluation
PSA
Prostate-specific antigen: a specific protein in the blood that is produced by the prostate
PSA levels
In general 4 ng/L, although as patients get older this number increases to account for increasing prostate size due to benign hypertrophy.
For a 49-year-old man, a PSA level of 2.5ng/L is considered good
For a 70-year-old man, a PSA level of 6.5ng/L is considered at low risk for prostate cancer.
PSA test/screening
PSA blood levels are routinely tracked in men >50years, this allows the doctors to monitor the blood levels over time and are able to assess an increase.
An elevated PSA level with no palpable disease in the prostate (stage T1c) is the most common presentation of the disease because of increased screening and awareness.
Age to start screening:
Average risk male with normal life expectancy (>10-year survival) begin screening at age 50
High-risk males begin screening with PSA at age 45
High-risk males with multiple 1st and 2nd-degree relatives with prostate carcinoma start PSA testing at age 40.
Anatomy of prostate
The prostate gland surrounds the male urethra and between the bladder and the urogenital diaphragm
The prostate gland consists of fibrous, glandular and muscular elements.
The seminal vesicles and vas deferens pierce the posterosuperior aspect of the gland.
T1 stage prostate cancer
T1: clinically unapparent tumour neither palpable nor visible with imaging.
- T1a: tumour incidental finding in 5% or less of tissue resected
- T1b: tumour incidental finding in 5% or more of tissue resected
- T1c: tumour identified with needle biopsy (due to elevated PSA level)
N staging prostate cancer
N0: no regional lymph node metastases
N1: metastases to regional lymph nodes
M stage prostate cancer
M1: distant metastasis
- M1a: non-regional lymph nodes (aortic, common iliac, deep/superficial inguinal, retroperitoneal)
- M1b: bone metastasis
- M1c: other sites with metastasis
Biochemical failure
Considered biochemical failure when the PSA is the lowest + 2ng/mL after treatment.
Considerations of observation only of prostate cancer
- T1-T2 staged tumour
- Gleason score of 2-6
- a PSA <10ng/mL
- a life expectancy of <10 years
With small well-differentiated tumours, the likelihood of having symptoms within 10 years is small.
Impotence
The inability to obtain an erection
Prostatectomy guidelines
Recommended for patients with T1 or T2 cancer with a greater than 10-year life expectancy.
Robot-assisted laparoscopy surgery has been shown to reduce erectile and bladder side effects.
Above T2 stage radiation therapy is recommended due to the bulk of the tumour.
High-risk treatment volume prostate cancer
Entire pelvis including lymph nodes
Lymph nodes: obturator, external, and iliac
May include boost to prostate and seminal vesicles.
Intermediate risk treatment volume prostate cancer
Prostate and seminal vesicles
Possible boost to prostate
Low risk treatment volume prostate cancer
Prostate + base of seminal vesicles (proximal 1-2cm)
Reasons for radiation after prostatectomy
- PSA does not decrease to the undetectable range immediately after surgery, signalling that all the tumour was not removed*
- PSA is undetectable after surgery but tumour margins contain a tumour or seminal vesicle is involved
- PSA is undetectable after surgery but after a period begins to rise.
*ensure that tumour is only in surgical bed and there is no evidence of metastasis
Results of surgery for prostate cancer
Overall PSA progression-free survival rates range from 70-85% at 5 years, and 45-75% at 10 years.
Results of radiation treatment in prostate cancer.
Both external and brachy therapies have similar results to surgery results.
For EBRT patients with a stage of T1-2, PSA <10ng/mL and Gleeson score of 6 or less the 10-year disease-free survival is 80%. this continues to increase with the development of more conformal techniques.
Similar patients show PSA disease-free survival of 80-90%, these patients are more highly selected with lower disease progression therefore higher % survival is expected.
Side effects of radiation therapy for prostate cancer
Acute GI issues may occur such as diarrhea, abdominal cramping, rectal discomfort and occasional rectal bleeding.
Urinary toxicity due to treatment of the urethra can occur. Such as urgency or frequency.
Sexual impotence may also occur.
Prognostic factors of prostate cancer
- pretreatment PSA
- Tumour size
- Gleason score & grade
Bad prognostic indicator
- perineural invasion/capsular invasion
Good prognostic indicator
- 5-year freedom biochemical failure
Treatment for low-risk category prostate cancer
EBRT to prostate and base of seminal vesicles only (+/- hormone therapy)
OR
Brachytherapy with I-125 monotherapy
OR
Radical prostatectomy
OR
Active surveillance
Treatment by risk category for intermediate-risk prostate cancer
Radical prostatectomy
OR
EBRT (prostate + SV) +/- brachytherapy
OR
EBRT + ADT
OR
Brachytherapy alone
Treatment by risk category for high-risk prostate cancer
EBRT to whole pelvis + ADT
OR
Combination: EBRT + brachytherapy + ADT
OR
Prostatectomy is discouraged
If post-prostatectomy:
EBRT is recommended if
- positive surgical margins of pT3-4
- indications for salvage RT + ADT for recurrent PSA
ADT
Androgen deprivation therapy. Prostate cancer cannot grow without androgen which includes testosterone and other male hormones.
MAB
Maximal androgen blockade is currently the most used hormonal therapy and mimics the results of bilateral orchiectomy. Consists of an injection of luteinizing hormone-releasing hormone and gonadotropin-releasing hormone (GnRH) receptor blockers given once every three months.
Anti-androgens
Can also be given to prostate patients to block testosterone from reaching the prostate and is taken daily in pill form.
T2 stage prostate cancer
T2: tumour confined within the prostate
- T2a: tumour involves one of half of one lobe or less
- T2b: tumour involves more than one half of one lobe but not both lobes
- T2c: tumour involves both lobes
T3 stage prostate cancer
T3: tumour invades through prostate capsule
- T3a: extracapsular extension (unilateral or bilateral)
- T3b: tumour invades seminal vesicle
T4 stage of prostate cancer
T4: the tumour is fixed or invades adjacent structures other than the seminal vesicles, bladder neck, external sphincter, rectum, pelvic wall.
