19. hormone dependent cancer Flashcards
where is the prostate gland?
it is based at the bottom of the bladder and surrounds the urethra
what happens when their is overgrowth in the prostate?
the urethra is blocked
the prostate gland is a secretory gland, what does it secrete? and where are these produced?
> factors that can nourish the sperm
proteases that can digest the seminal clot
produces a large proportion of seminal fluid
- produced in ducts
what are the gland that produce milk called? and what are they surrounded by?
mammary glands empty into large ducts and milk exits out the nipple
>surrounded by stroma
what are prostate ducts surrounded by?
stroma - this contains lots of smooth muscle for ejaculation contraction forcing ejaculation of the urethra
describe a single gland
secretory epithelial cells are cuboidal in shape and come together to form specialised glands
>substances accumulate in the lumen and then are expelled
what type of glands are breast and prostate?
exocrine - secrete their products into ducts
what are the stroma that surround the prostate gland?
smooth muscle, fibroblasts, nerves and lymphatics
what is the function of the basal epithelial layer of cells?
ensure that secretions are forced out the duct - they high tight cell-cell junctions to prevent escape into serum
what are the secretory cells called in the prostate?
luminal epithelial cells
which cells are the major cell type in the prostate gland and how are they implicated in cancer?
luminal epithelial cells
these are the cells which cancer most commonly arises in
which cell type in the prostate are androgen dependent for growth?
luminal epithelial cells
are basal epithelial cells reliant on androgens for growth?
no
where is the stem cell population believed to be in the prostate?
basal epithelial cells
where do >90% breast and prostate cancers arise ?
in luminal epithelial cells
what happens to the basal epithelial layer of cells when cancer arises?
in all prostate cancer and most breast, this layer of cells disappears
what happens as tumour becomes more aggressive?
there is increasing loss of glandular structure
how common is breast and prostate cancer? and how well is it diagnosed?
very
>after skin cancer they are the most commonly diagnosed
what has the largest death rate?
lung cancer - it is not easily diagnosed
what is the lifetime risk of breast cancer
1 in 8
how many people develop and how many people die of breast cancer a year in the UK
50,000
12,000 - 2nd largest killer after lung
since introduction of mass breast screening what was seen?
reduction in mortality - early detection gives patient better prognosis
name 11 risk factors for breast cancer
- age
- race
- environment
- diet
- family size
- age of first pregnancy
- age of first period
- age of menopause
- exogenous hormones
- obesity
- family history
how is age implicated in breast cancer?
breast cancer is more common in the over 50s
how is race implicated in breast cancer?
higher incidence in the west
how is family size implicated in breast cancer?
changes in the mammary gland structure which are associated with pregnancy can also be protective
>having a baby before 30 seems to be protective
how is age of first pregnancy, period and menopause implicated in breast cancer?
fewer menstrual cycles in a lifetimes the lower the risk of breast cancer
how are oral contraceptive implicated in hormone dependent cancer?
reduce the risk of endometrium and ovarian cancer but do appear to slightly increase the risk of breast cancer
>this is reversible, stop taking the pill and risk decreases
how is weight implicated in breast cancer?
fat tissue can synthesise steroid hormones, obesity is associated with increased risk of breast cancer
how does the diet implicate breast cancer?
the vegetarian diet reduces the risk of breast cancer
how is family history implicated in breast cancer?
increases risk of breast cancer although most breast cancers are sporadic
>familial breast cancer is heterogeneous
name 4 genes implicated in familial breast cancer
BRCA1
BRCA2
PTEN
p53
what can be done for women worried they may get familial breast cancer?
> genetic screens
>removal of breast
how penetrant are BRCA mutations?
highly
>70% BRCA1 carriers with family history develop tumours by age 70
how much of breast cancer do familial BRCA1 and BRCA2 cases account for?
2-5%
what are BRCA1 and BRCA2?
TS involved in DNA damage and transcription
>BRCA1 is involved in non-homologous end joining
>BRCA2 is involved in nucleotide excision
what is the lifetime risk of prostate cancer?
1 in 8
how is the incidence of prostate cancer changing?
it is increasing (even after age adjustment)
name 4 risk factors in prostate cancer?
- age
- race
- family history
- diet
how is race implicated in prostate cancer
higher incidence in those of African descent - this may be due to genetic polymorphism
how is diet implicated in prostate cancer
- red meats, dairy and high fats
- protective effect of vegetarian diet and soya
prostate cancer in familial cases is very heterogeneous. name two genes which are implicated in familial prostate cancer
- PTEN
- BRCA2
how is PTEN implicated in prostate cancer?
mutations can cause prostate cancer progression in an aggressive manner
how us BRCA2 implicated in prostate cancer?
accounts for 5% of familial prostate cancers
>most highly linked tumour suppresser genes in prostate cancer
>highly penetrance, 5 fold higher lifetime risk, increases to 7 fold after 65
what are two symptoms are an enlarged prostate? and why this often lately diagnoses?
problems urinating
lower back pains
>can also be asymptomatic as very internalised gland