Gynaecological Tumours Flashcards
(189 cards)
Where can gynaecological tumours arise?
Vulva Cervix Endometrium Myometrium Ovary
What is the transformation zone?
Where the endothelium of the cervix undergoes metaplasia from glandular to squamous epithelium
How does the transformation zone differ between older and younger women?
In younger women, the transformation zone is further out into the ectocervix
What are almost all cases of CIN and cervical carcinoma related to?
High risk HPVs
What are HPVs?
DNA viruses
How many types of high risk HPVs are known?
15
What are the most important HPVs in the pathogenesis of cervical carcinoma?
16 and 18
What % of cases of HPV are related to HPV 16?
60%
What % of cases of cervical carcinoma are related to HPV 18?
10%
How does HPV lead to the development of CIN or cervical carcinoma?
Infect immature metaplastic squamous cells in the transformation zone
What is the result of HPV infecting the immature metaplastic squamous cells in the transformation zone?
More common in younger women, as they have more transformation zone available to infect, therefore easier to catch
How does infection with HPV cause CIN?
They produce viral proteins E6 and E7
What do viral proteins E6 and E7 do?
Interfere with the activity of tumour suppressor proteins (p53 and RB) to cause inability to repair damaged DNA and increased proliferation of cells
Activate telomerase to cause cell immortality
What is true of most genital HPV infections?
They are transient and eliminated by the immune response in months
What do the risk factors for CIN and cervical carcinoma relate to?
Mostly related to HPV infection
What are the risk factors for CIN and cervical carcinoma?
Sexual intercourse Early first marriage Early first pregnancy Multiple births Many partners Promiscuous partner Long term use of OCP Partner with carcinoma of the penis Low socio-economic class Smoking Immunosuppression
Describe the prevalence of cervical cancer worldwide?
It is the third most common cancer in women
What has caused the rate of cervical cancer to decrease significantly?
Introduction of screening
What makes cervical cancer a good condition for screening?
Cervix accessible to visual examination
Slow progression from precursor lesions to invasive cancers
Pap test detects precursor lesions and low stage cancers
Allows early diagnosis and curative therapy
How can the cervix be accessed for visual examination?
Colposcopy
How long does the progression from precursor lesions to invasive cancers take?
Years
What does cervical screening involve?
Cells from the transformation zone are scraped off, stained with Pap stain, and examined microscopically
Other than Pap staining, how can cervical screens be interpreted?
Test for HPV DNA in cervical cells - molecular method of screening
How is testing for HPV DNA in cervical cells often used?
To make a judgement when cells are mildly atypical