B8.048 Prework 1: Screening for and Diagnosis of Prostate Cancer Flashcards
what is the prostate
a gland in the pelvis
purpose of the prostate
reproduction
makes the seminal fluid (non-sperm) portion of the ejaculate to nourish sperm
stored in the seminal vesicles
composition of the prostate
glands: source of adenocarcinoma of the prostate
stroma: contains the suportive tissues such as the smooth muscle, vessels, and autonomic nerves, source of the non-adenocarcinoma prostate cancers (sarcomas)
seminal vesicles
risk factors for prostate cancer
increasing age
AA race/ethnicity
fam history of prostate, breast, ovarian, and pancreatic cancers
genetic syndromes/conditions: lynch, BRCA2
AUA screening guidelines
40-54: men at risk
55-69: shared decision making
american cancer society screening guidelines
50+: average risk with life expectancy > 10 years
45+: men at high risk
40+: men at highest risk, more than 1 first degree relative
NCCN screening guidelines
45-75
USPSTF screening guidelines
55-69
should you screen men >70 for prostate cancer?
depends on their sitch
if they are going to live a while, yes
PSA
protein produced by the prostate and secreted into seminal fluid to liquify semen
how does PSA get into the serum
loss of the basal cell layer (hallmark of prostate cancer histologically) results in leakage of PSA into blood stream > thus returning elevated levels
2 components of prostate cancer screening
PSA and DRE
DRE
palpation of the prostate for nodularity
palpable lesion = 40% risk of incident prostate cancer
prostate zones
transition zone = 20%
central zone = 5%
peripheral zone = 70-80%
accuracy of a PSA screening
PSA > 4 used
-PPV 30%
-NPV 85%
unfortunately with PSA < 4, 15% of men will have high grade disease
why can people with PSA < 4 have high grade prostate cancer
younger men have smaller glands; less BPH driven PSA, so lower PSAs can be more concerning
prostate cancer cells can make less PSA by volume than normal prostate cells (not normally functioning cells)
risks of prostate biopsy
discomfort pain bleeding (urine, stool, semen) transient ED infection (2-4% get post biopsy sepsis)
contemporary schema for assembling of screening info
concern > shared decision making > PSA and DRE
if PSA elevated: biomarker or MRI > biopsy if abnormal
if abnormal DRE: prostate biopsy
additional tests for prostate cancer screening
4K score
PHI
PCA3
MRI
4K score
total PSA, free PSA, intact PSA, kallikrein-related peptide 2
clinical factors
AUC for clinically significant prostate cancer: 0.77-0.82 (better than PSA)
PCA3
PCA3 ad PSA RNA in post DRE urine samples
approved in men with a negative prior biopsy
NPV 90%
multi-parametric MRI with fusion biopsy
T2 weighted dynamic contrast enhanced diffusion weighted imaging approved for men with a prior negative biopsy -NPV: 90% -PPV: 60%
advantage of MRI over blood tests
approved (get coverage) and offers ability to target
targeted biopsy
uses US and MRI fusion software
targets lesions identified on MRI for biopsy
tracks where biopsies were obtained
lifetime risk of prostate cancer death across population
2.8%
does PSA screening decrease mortality?
21% RR in cancer mortality
29% when adjusted for noncompliance
1.07 deaths per 1000 men
NTT of PSA screening
781 men screened
12 cancers detected
to prevent 1 death at 13 years
why not screen for prostate cancers?
large number screened to avert 1 death
false positive PSA values result in unnecessary biopsies
some men who receive treatment don’t need it
