Case 4- colon cancer, staging and screening Flashcards
Why is grading and staging important
Useful for evidence-based prognosis and may indicate different treatment. Helps communication between health professionals as you don’t have to describe the cancer in detail
Cancer grading
Histological and is based on tissue samples from a biopsy, looking at how aggressive the cancer is. It looks at the degree of differentiation between the tumour and normal tissue. Tumours which are poorly differentiated will be very different to normal tissue and will be more aggressive.
How can degree of differentiation be determined by
- Mitotic activity- more aggressive tumours will have increased mitotic activity
- Nuclear size- more aggressive tumours will have increased DNA replication meaning that the nucleus size within cells increases
- Hyperchromasia (how dark the nucleus is)- increased DNA replication in aggressive tumours causes the nucleus to appear darker when looked at under the microscope, as it contains more DNA than usual
Bowel cancer grading
GX - cannot be identified - for example the tissue sample may not have been labelled correctly
G1 - well differentiated
G2 - moderately differentiated
G3 - poorly differentiated
G4 - undifferentiated (anaplastic tissue)
Cancer staging
Is anatomical and is based on scans, it looks at how widespread the cancer, will also look at its size and if it entered the lymphatic system
Most common staging method
TNM is the most common staging method, it stands for tumour size, nodal involvement and metastases. It will be written in the format T2N1M0
Staging tumour size guide
TX- tumour size cant be assessed, no scans or imaging T0- no tumour present Tis- ‘tumour in situ’. The tumour has malignant potential, the biopsy shows increased mitotic activity or an enlarged nuclei, but the tumour has not yet invaded through the basement membrane. T1- into submucosa T2- into muscularis propria T3- into subserosa T4a- into visceral peritoneum T4b- attached to other organs/structure
Staging nodal involvement
NX- cant be assessed
N0- no lymph nodes involved
N1- 1 single lymph node involved or more then one lymph node is involved but they are all part of the same group of lymph nodes
N2- more then one group of lymph nodes affected
Staging metastases involvement
M0- no metastases present
M1- metastases are present (either one or multiple)
Stage 0-4 cancer
A stage 0 cancer is one where the tumour is in situ (has malignant potential but hasn’t invaded through the basement membrane. Stages 1, 2 and 3 show that there is local growth and spread. In stage 4 there is distant metastases.
Screening and public health
Screening is a part of secondary disease prevention. It helps identify a disease at its early stage so it can be more easily managed
Types of prevention
Primary prevention- reducing the risk of a disease i.e. immunisation or banning toxic substances
Secondary prevention- identification/ management of an early disease i.e. screening and self-breast examinations by women
Tertiary prevention- prevention of chronic and disabling effect of a disease i.e. chronic disease management programmes and support programmes
Screening
Not a diagnostic procedure but instead identifies apparently healthy people who are at an increased risk of a disease or a condition. They can then be offered information, further tests and appropriate treatment to reduce their risk and/or any complications arising from the disease or condition.
Fetal anomaly screening programme
Screens for 11 structural anomalies including down’s syndrome. Multiple tests done between 10 and 20 weeks
Infectious diseases in pregnancy screening (IDPS) programme
Offers testing for hep B, HIV and syphilis. Usually done at 10 weeks
New-born and infant physical examination (NIPE) screening programme
Screens new-borns within 72 hours and at 6-8 weeks after birth, including hips, eyes and hearts
New-born blood spot (NBS) screening programme
Heel prick test at 5 days old. For sickle cell, CF, congenital hypothyroid, inherited metabolic diseases, e.g phenylketonuria, MCADD
New-born hearing screening programme (NHSP)
Offered to all babies within 4-5 weeks to test hearing
Sickle cell and thalassaemia (SCT) screening programme
All pregnant women in England are offered a blood test to find out if they carry a gene for thalassaemia. Those at high risk of being a sickle cell carrier are offered a test for sickle cell.
Diabetic eye screen
Yearly retinal exam of all people with a diagnosis of diabetes over age 12
Bowel cancer screening
FIT tests for all adults aged 60-74, every two years. gFOB test is also used. In the FIT test the end of a stick is dipped into a single bowel motion, replaced in a tube and returned in a prepaid envelope
Cervical cancer screening
LBC test for all women. Aged 25-49, every 3 years. for those aged 50-64 it’s every 5 years