Cervical Screening Flashcards
at what age do most HPV infections occur?
15-25
vaccination reduces high grade cervical cancer by what %?
95
age group with highest risk of CIN?
25-35
describe the scottish cervical recall system
- Smear take enters request details onto SCCRS database
- Vials sent to lab receipt logged on SCCRS
- Patient details received from SCCRS, vials processed, slides stained and screening
- Cytology lab results put on SCCRS database
- SCCRS creates colposcopy referral
- Woman and GP receive results
describe the cervical screening programme
- Women aged 25-64
- 3 yearly smears up to 50
- 5 yearly from 50
- Liquid based cytology (LBC)
- From 2020 it will be every 5 years for everyone
how does the cervix change with puberty?
During puberty the cervix increases in size and so the squamous columnar junction everts. The lactobacillus bacteria in the vagina produces lactic acid making the vagina acidic. The columnar epithelial don’t like this and so normal metaplasia occurs resulting in the transformation zone. This is where you will find HPV infections and cancer.
what is cervical cytology?
Cytology involves the microscopic detection of squamous cells that are suggestive of underlying cervical intraepithelial neoplasia. It is carried out to identify women that have no abnormality and those requiring further investigation.
cervical cytology: normal
• Squamous epithelial
• Other cells – glandular cells, inflammatory cells
• Benign nuclear features
o Small
o Uniform size and shape
o Fine regular chromatin evenly distributed
cervical cytology: abnormal - dyskaryosis
• Abnormal cells may be few • Nuclear features o Increased size and nuclear:cytoplasmic ration • Variation in size, shape and outline • Coarse irregular chromatin • Nucleoli • Graded low or high grade dyskaryosis o Reflects underlying CIN • Low grade (+ borderline nuclear abnormality) = 8% • High grade = 1.4%
what is CIN?
This is abnormal proliferation of the cells in the squamous epithelium and is invisible to the naked eye. Almost all CIN and cervical cancers are associated with HPV infections particularly types 16 and 18.
risk factors for CIN
- Early age at first intercourse
- Multiple sexual partners
- Prolonged oral contraceptive use
- Smoking
- STDs
- Immunodeficiency
- Persistent infection
- Viral DNA > integration in host cell genome > overexpression of viral E6 and E7 proteins > deregulation of host cell cycle
CIN development
CIN is the precursor of invasive cancer. Disarray in the arrangement of the cells within the epithelium, variation in cellular size and shape, nuclear enlargement, irregularity and hyperchromatism can all be seen. There are currently 3 grades of severity
CIN can either regress or persist. A minority (20-30%) of CIN3 will progress to invasive cancer over 10-
20 years if left untreated. Squamous carcinoma is the malignant change in squamous cells of the
transformation zone of the cervix.
treatment of CIN
LLETZ
cold coagulation
laser ablation
aims of follow up after CIN treatment
• To confirm that treatment was effective
• To prevent invasive cancer
o Recurrent disease in 5% after 3-5 years
o Detect occasional cancer
• To reassure the women
• After treatment
o Increased risk of cervical cancer compared to normal population
o Follow up LBC at 6 months for cytology and high-risk HPV
o Both negative – return to recall
o Either positive – return to colposcopy
peak age for cervical cancer
45-55
