Lecture 18 - Neoplasia 6 Flashcards
What is cancer screening?
When cancers with a significant burden are screened for
Attempts to detect cancers as early as possible
What are the benefits of cancer screening?
-Detect problem early before patient has any symptoms
-Treatment more effective if the problem is detected early
-reduce number of deaths from screened diseases
-can help individuals make better informed decisions about their health
What are the risks/limitations of cancer screening?
-False positives + false negatives
-some results can lead to difficult decisions
-anxiety associated with knowledge of a health problem
-person could get a -ve but later go onto develop condition
What is a normal (screen negative) screening result?
Low risk of having the condition you were screened for
What is a high risk (screen positive) screening result?
May have condition you’ve been tested
Further tests give to confirm this
What is a false positive screening result?
Someone with a. Positive screening result who does not have the target condition
What is a false negative screening result?
Someone with a negative screening result who DOES have the target condition
What is sensitivity for a screening programme?
What does it mean if a test is highly sensitive?
Ability of the screening test to identify people with the conditions as positive
Highly sensitive = few false negatives
What is specificity for a screening programme?
What does it mean if a test is highly specific?
Ability of the screening programme to identify healthy people as negative
Highly specific test = few false positives
What are the 3 most common screening programmes?
Breast cancer
Cervical cancer
Colorectal cancer
Who are normally screened for Abdominal Aortic Aneurysm?
Men over 65yrs
How frequently do women between the ages of 47-73 yrs receive mammograms?
Every 3yrs
How frequently are women between ages 25-49 screened for cervical cancer?
Every 3 years
How frequently are women aged 50-64yrs old screened for cervical cancer?
Every 5 years
What are home test kits for bowel cancer screening looking for in men and women between 60-74?
Blood in faeces
What is being screened for in babies between 10-12 weeks old?
What causes these diseases?
Down’s syndrome (Trisomy Chromosome 21)
Pataus syndrome (Trisomy Chromosome 13)
Edward syndrome (Trisomy Chromosome 18)
Why is diabetic eye screening done especially in pregnancy?
Blood sugar control is really varied in pregnancy
What are the screening programmes for new born babies?
Physical exams
Hearing exam
Blood spot/heel prick test
What are the 5 conditions that are screen for in the heelprick/bloodspot test?
Sickle cell disease
Cystic fibrosis
Congenital Hypothyroidism
6 Inherited metabolic diseases
Severe Combined Immunodeficiency (SCID)
What are the 6 inherited metabolic diseases screened for in the heel prick test?
Phenylketonuria (PKU)
MCADD
Homocystinuria (HCU)
Maple syrup urine disease (MSUD)
Isovaleric acidaemia (IVA)
Glutaric aciduria type 1 (GA1)
What is being tested for in the smear test for the Cervical Cancer Screening Programme?
High risk (HPV) Human Papilloma Virus in the cells
When are the cervical cells assessed under the microscope in the Cervical Screening Programme (smear test)?
When HPV positive
How is a cervical smear test done?
Speculum opens the walls of the vagina
A little brush brushes the cervix to collect some cells
Cells then tested for HPV
What is dyskaryosis?
Dysplasia (an interchangeable term)
When the cervical screening test is +ve for HPV and cells have abnormal changes
If a smear test is HPV +ve why is important to check the cells under a microscope?
Checking for dysplasia/degree of dysplasia
What are some changes that occur in dysplasia?
Increased nuclear size
Cells become darker
Irregular size and shape
When does dysplasia become invasive cancer?
When the cells invade the basement membrane
How may self sampling help in the cervical screening programme?
May encourage non -attenders to take part
How May extending recall intervals affect cervical screening?
hrHPV testing has a high negative predictive value
By extending the screening interval to 5yrs for all women helps reduce burden on NHS
Who are screened for Abdominal Aortic Aneurysms?
Men over 65yrs old
What is considered an abdominal aortic aneurysm?
Aorta diameter over 3cm wide
What are the 3 types of aneurysm?
Fusiform
Saccular
Mycotic
What is a Fusiform aneurysm?
Aneurysm bulges out on ALL sides of the blood vessel
What is a saccular aneurysm?
Aneurysm bulges out only on the one side
What is a mycotic aneurysm?
Aneurysm caused by bacterial infection of the arterial wall
How are people with abdominal aortic aneurysms managed?
3 - 4.4cms (yearly surveillance)
4.5 - 5.4cms (3 monthly surveillance
5.5cms > referral to cardiovascular surgeon
How are abdominal aortic aneurysms usually operated on?
Stent graft inserted
This creates a new tube in the aorta preventing the blood flowing to the weakened areas/walls
How can we measure the performance of a screening programme?
Incidence
Reduction in mortality
Interval cancers (if -ve doesnt mean your not going to develop cancer later)
What is lead time bias?
When a disease is detected by a screening or surveillance test at an earlier time point than it would have been if it had been diagnosed by its clinical appearance
May have been asymptomatic for a while
Therefore it appears that the patient survives longer with the disease
Why is over diagnosis n issue with screening programmes?
A disease which is insitu and may have remained in situ would be surgically removed as a precaution (it may have never actually developed into cancer)
