Screening Programmes Flashcards
what is screening
a test offered to an asymptomatic person to detect those who have a high probability of having a disease
what are the principles of early disease detection
Wilson + Junger
1- the condition should be an important problem for the individual and the community (IMPORTANT)
2- the disease should be an accepted treatment for patient with the disease (TREATMENT)
3- facilities for diagnosis and treatment should be available (FACILITIES)
4- there should be a recognisable latent or early stage (LATENT)
5- there should be suitable test or examination (TEST)
6- the test should be acceptable to the population (ACCEPTABLE)
7- the natural history of the condition, including development from latent to declared disease, should be adequately understood (UNDERSTANDING)
8- there should be an agreed policy on whom to treat as patients (PATIENTS)
9- the cost of the case finding programme should be economically balanced in relation expenditure on medical care as a whole (COST)
10- case finding should be a continuing process (CONTINUING)
I take flowers (lilies) to another undertaker past crematory casket
How is cervical cancer an important problem for the individual and community
incidence has fallen since the early 1980s
death has also fallen (5 year survival was 50% in the early 70%)
- now 60%
causes 105 deaths in Scotland and 852 in the UK/ year
what is the accepted treatment for cervical cancer (rule 1)
all cancers are staged using clinical exams, pathology and radiology
gynaecology/ oncology multidisciplinary team meeting
- 1 a week
management is based on the stage/ fitness
what are the differences in treatment for different stages of cervical cancer (rule 2)
small cancers = outpatient
larger tumours = radical hysterectomy
inoperable tumours = chemotherapy and radiotherapy
what are the facilities for diagnosis for cervical cancer (rule 3)
if abnormality is detected, a formal diagnosis is then required
- a biopsy for cervical cancer
in CSP (cervical screening programmes), referred to colposcopy for both diagnosis and treatment
what is the suitable test for cervical cancer (rule 5)
Cervical Smear Test
- carried out at a GP/ sexual health centres
- a brush is used to remove cells from the cervix
- these are transferred to a pot of preservative
- then tested for HPV (human papilloma virus) +/- cytology
speculum used to hold open the cervix/ lubricant
how is the cervical cancer test acceptable to the population (rule 6)
depends on perceived risk and how inconvenient/ unpleasant the test is
promotion -> posters to show
- speed
- normality
- effectiveness
how is case finding a continuing process for cervical cancer
Scottish Cervical Call Recall System (SCCRS)
- generates invitations for women to attend for a smear test
- 25-65 invited every 5 years
- women who have abnormal tests are called more frequently
- computer system interacts with other software to refer patients to colposcopy when required
- colposcopy visits are documented and follow up in the community (GP) can be organised by SCCRS once the patient is discharged
what are the components of cervical cancer screening
Call Recall office and SCCRS
smear takers
laboratories
colposcopy service
what are the risk factors associated with cervical cancer
smoking
poor immune function (e.g. immunosuppression)
multiple sex partners
what is HrHPV
a high risk subtype of HPV
- majority of cervical cancers
what type of virus is HPV
DNA
- high risk and low risk
- over 200 types (40 are STIs)
what circumstances create risk of someone developing pre-cancerous changes with cervical cancer
patients who have persisting infection with a high risk oncogenic subtype of HPV
what does the endocervix look like
rough area
inner
what does the ectocervix look like
smooth + shiny
ouer
what is the epithelium of the endocervix
simple cuboidal epithelium
- musin
what is the epithelium of the ectocervix
squamous epithelium
describe the progression of an HPV infection
1- micro abrasions expose the BM
2- allows for infection of HPV
3- HPV replicates in maturing squamous cells
4- produces koilocytes
describe the end result of low risk HPV infection
free rival DNA within the cell
responsible for viral warts (e.g. 6, 11, 42, 44)
describe the end result of high risk HPV
incorporate their DNA into that of the host cell
viral E6 and E7 proteins are responsible for reactivating the cell cycle in cells which are not normally proliferating
persistent infection/ disruption of cell cycle -> proliferation of epithelial cells -> precursor lesions for cervical cancer (CIN and CGIN)
list examples of high risk subtypes of HPV
16, 18, 31 and 45
what is CIN
cervical intraepithelial neoplasia
- CIN1, CIN2, CIN3
how does CIN1 resolve in most patients
without treatment
patients are monitored
what is CIN3
CIN3 precursor lesions for squamous cell carcinoma -> usually takes >2 years to develop into invasive carcinoma
what is the CSPs main purpose
to detect and treat CIN2 and CIN3
what is CGIN
cervical glandular intraepithelial neoplasia
much less common and is the precursor lesion for adenocarcinoma
describe the appearance of a sample of cervical tissue stained with H + E when affected by CIN1
higher nucleus to cytoplasmic ratio –> hyperchromatic (darker) appearance
cells have less cytoplasm
towards the top, nuclei are a little large -> koilocytes
describe the appearance of a sample of cervical tissue stained with H + E when affected by CIN3
can develop from CIN1
affects all layers of squamous epithelium
all cells have larger nucleus
describe the path a cervical sample takes in the lab
HPV testing (all)
Cytology testing (15%)
- samples with a +ve HPV test
- samples from patients on follow up pathways (for previous cytological or histological abnormalities)
who is called back after HPV testing is complete (14 high risk subtypes)
positive -> recall in 5 years (machine interface with SCCRS)
negative -> sample tested for cytology
fail
specific subtype is not reported
what is dyskaryosis
transformation zone cells are spread out
abnormal cells have enlarged, irregularly shaped nuclei
how is dyskaryosis graded
mild, moderate or severe depending on the size of the nucleus
what do the dyskaryosis grades roughly equate to
CIN1, CIN2, CIN3 on histology specimens
- biopsy is needed to confirm the degree of abnormality
what is the treatment for someone who tests positive for HPV
patients who test positive but have no cell changes are called back in 1 year for a repeat HPV test
patients who have cell changes are referred to colposcopy investigation
what is a colposcopy
examination of the cervix using a specialist microscope
acetic acid is applied to highlight any abnormalities
patients can have biopsies taken and treatments for abnormalities detected
what is the risk of developing breast cancer in Scotland
1/8 women -> increases with age
how often do women need to get a mammogram
women ages 50-70 are invited to attend every 3 years
what were the results of breast cancer screening in 2018
1573 cancers and 198 non-invasive cancers were detected
what is the process of breast cancer screening
appointment takes 30 mins and 2 x-rays are taken of each breast
images are interpreted and the results sent to the GP and patient
what is the treatment for patients with abnormal or unsatisfactory x-ray results
4-5% of patients
sent to hospital for triple assessment
- examination
- radiology -> repeat mammogram or ultrasound (if necessary)
- biopsy
describe the appearance of normal breast tissue
central duct
lobules
fibrous tissue (pale pink)
adipose cells (white)
what is the structure of the ducts in the breasts
2 layers
inner tall cuboidal (high nucleus to cytoplasm ratio)
no cytological atypia
no mitotic activity
- surrounded by basal layer (less visible)
describe the appearance of breast tissue with cancer
cells infiltrating within the fat cells
no ducts or lobules
variation between nuclei is subtle in certain subtypes of cancer
pleomorphism
what was the bowel cancer screening programme trialled and subsequently rolled out
2006 and 2009
which portion of the population is most susceptible to bowel cancer
over 50s
what is the aim of bowel cancer screening programmes
to detect precancerous changes (often polyps) and early cancers which are treatable and have a better prognosis
what is the screening test for bowel cancer
a faecal immunochemical test (FIT) is sent in the post for completing at home
- patients 50-74 = every 2 years
one sample of stool is collected and returned in a pre-paid package
what is the stool sample tested for in bowel cancer screening
detecting blood
small, unnoticeable -> haemoglobin more accurate
if above 80ugHb/ faeces -> colonoscopy
1 in 5 referred
1 in 10 already have cancer
describe the appearance of normal bowel tissue
large cytoplasm -> musin for lubricating movement of contents
mucosal elements should remain superficial to muscle
describe the appearance of a polyp with H + E
fibrovascular stalk - attaches to wall
disordered architecture
- cystically dilated glands; bigger lumina
bluer than should be
- less musin, more nucleus
describe the appearance of cancerous bowel tissue with H + E
dysplasia
- more blue
- glands are more closely packed (haphazardly arranged, not tubular shaped)
cribriform
invasive adenocarcinomas
- invading underlying tissues
