Screening Flashcards
What characteristics make a tumour ideal for screening?
- Curable when detected early in the majority
- Relatively common
- Long pre-invasive or non-metastatic stage
- Distinct from benign lesions
- Detected by relatively simple tests
What would make up the ideal screening test?
- Detect cancer early enough to implement effective treatment
- Sensitive & specific
- Well tolerated (improving compliance)
- Inexpensive
- Easy to administer/perform
- Well publicised (high uptake)
What are the advantages of screening?
Reduction of mortality by detecting disease that is curable
Less radical treatment- reduced morbidity
Savinf on health service resources by inc cure rates
Reassurance given by negative test
What are the disadvantages of screening?
Inc length of anxiety & morbidity if no effective intervention possible
Over-investigation of false positives (associated morbidity)
Over-treatment of borderline cases
False reassurance from a false negative
Possible harmful effects of screening
Cost
What screening programmes are available in the UK?
Cervical Cancer: women 25-49 every 3years, 50-64 every 5years.
Breast Cancer: Mammography for women 50-70 every 3years
Colorectal Cancer: Men & women faecal occult blood every 2years from 60-69 to be extended to 74.
What happens when the results of a mammogram are received?
Results to patient/GP in 2weeks
1in23 called back for further assessment (Triple assessment)- 1in4 of these has breast Ca
How is a person counselled before going for a mammogram
Letter sent out with date (can be rearranged)
Lasts around 30mins
Procedure requires removal of clothes including bra
Avoid: Talc, spray on deodorant
Procedure: Breasts x-rayed one at a time flattened by a machine for good quality image, some find this uncomfortable/painful
Implants: Mammogram still the best way but early detection more difficult due to opacification- may need additional tests
When should a cervical screen be rescheduled?
Menstruation <12 weeks postnatal <12 weeks after a TOP/miscarriage Vaginal discharge or pelvic infection — Tx the infection If the woman is pregnant
What should be done if the cervix appears abnormal?
Urgent referral for 2week review by gynaecologist
What are the requirements of cervical screening post-CIN treatment?
Increased risk of developing Cervical cancer
Followed up for test of cure cytology 6m post-Tx
If -ve/low grade/borderline then HPV test taken
High grade: Refer to colposcopy no need for HPV test
+ve: Refer to colposcopy
-ve: Repeat cytology in 3y
How are abnormal cervical screening results managed?
Borderline changes in squamous/endocervcial cells OR low grade dyskaryosis:
HPV test on cytology sample
+ve: Refer to colposcopy within 6weeks
-ve: Return to screening program
High grade dyskaryosis (mod-severe):
Colposcopy (2week wait)
Suspected invasive cancer/ glandular neoplasia:
Colposcopy (2week wait)
What tests might be done at colposcopy?
Colposcope: Visualise any abnormalities
Acetic acid: Abnormal areas (CIN) turn white
Iodine solution: Normal tissue stains brown, pre-cancerous abnormalities may not stain, cells on inner cervix don’t stain
Biopsy: Confirm diagnosis
What happens after an inadequate cervical screen occurs?
Repeat screen <3months
3 consecutive inadequate samples: Refer to colposcopy <6weeks