Cervical cancer & intraepithelial neoplasia Flashcards
Define cervical cancer & intraepithelial neoplasia.
Cervical cancer is a human papillomavirus-related malignancy of the uterine cervical mucosa.
Most commonly from metaplastic squamous cells in the transformation zone
Explain aetiology of cervical cancer & intraepithelial neoplasia.
HPV detected in 99.7% squamous cell carcinomas + adenocarcinomas (most common types)
HPV-16 + 18 are the most common high-risk types.
Other high-risk types inc. 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 68, 73, + 82.
Describe the prevalence of HPV
Most sexually active adults will be exposed to HPV
Immune system clears the virus in 6 months in 50%, + 2y in 90%
Summarise the epidemiology of cervical cancer & intraepithelial neoplasia.
4th most common malignancy in women worldwide.
50% occurs in <45y
Incidence rates in UK highest in 25-29y
Give 8 risk factors for cervical cancer
Smoking
HIV
Persistent HPV infection
Early 1st intercourse
Many sexual partners
High parity
Low SES
COCP
What are the 2 types of cervical cancer?
Squamous (80%)
Adenocarcinoma (20%)
How does HPV cause cervical cancer?
HPV 16+18 produce the oncogenes E6 + E7 respectively
E6 inhibits p53 tumour suppressor gene
E7 inhibits RB suppressor gene
How may cervical cancer present?
Routine cervical cancer screening
Abnormal PV bleeding, PCB, IMB, PMB
Discharge foul smelling/ bloody
Dyspareunia
What investigations are required for cervical cancer?
Speculum: cervical mass +/- bleeding
Smear for hrHPV + cytology (abnormal cells)
Colposcopy
CTCAP
Discuss in MDT
What is cervical intraepithelial neoplasia?
Premalignant epithelial dysplasia
CIN I: least invasive, ~1/3 of basal epithelium. Architecture mostly intact
CIN II: <2/3 basal epithelium, loss of architecture.
CIN III: Severe, irreversible, full thickness, carcinoma in situ
What cells are pathogonomic for HPV infection, which may be seen in CIN?
Koilocytes
Describe the epithelial lining of the cervix
Ectocervix: squamous
Endocervix: glandular
What are the initial investigations for cervical cancer?
Speculum: Cervical mass may be seen, cervical bleeding
Cytology: Look for HPV and then abnormal cells
CIN grading can be done after histology
What is the management for cervical cancer & intraepithelial neoplasia?
CIN/ IA1: LLETZ or cone biopsy.
IA2-IB2: Radical TAH + BSO +/- chemo/ radio
IB3-IVA: radio + chemothrapy.
IV: Systemic chemo
What are the complications of LLETZ and cone biopsies?
Cervical shortening can lead to cervical incompetence which can lead to mid trimester miscarriage + preterm labour
Summarise the prognosis for patients with cervical cancer & intraepithelial neoplasia.
5y varies based on disease stage at diagnosis:
I: 92%
II-III: 56%
IV: 17%.
When are smear tests offered?
25-49y: 3 yearly
50-64: 5 yearly
Best mid-cycle
How are pregnant women advised regarding smear tests?
Delay smear until 3/12 postpartum unless missed screening or previous abnormality
What is the treatment for CIN?
Large loop excision of transformation zone (LLETZ)
Cone biopsy (larger lesions)
What are the stages of cervical cancer?
I: tumour confined to cervix
II: tumour invades beyond uterus, but not into pelvic wall or lower 1/3 vagina
III: Tumour invades pelvic wall +/- involves lower 1/3 vagina +/- causes hydronephrosis or non functioning kidney
IV: carcinoma extends beyond true pelvis/ involves mucosa of bladder/ rectum
Which chemicals are applied during colposcopy for better visualisation?
Visual Inspection with Acetic Acid (VIA)
or
Visual Inspection with Lugol’s Iodine (VILI)
How is visualisation with acetic acid performed?
Apply acetic acid to cervix
If cervical epithelium contains an abnormal load of cellular proteins, the acetic acid coagulates the proteins, giving the concerning area an opaque WHITE coating
“Acetowhite”
What is Lugol’s iodine test also known as?
Schiller’s iodine test
What is Lugol’s iodine test?
Apply iodine-based solution.
Iodine solution is glycophilic, normal glycogen containing squamous epithelium stains brown or black.
CIN + invasive cancer has little glycogen + does not stain. Columnar epithelium is also deficient in glycogen so does not stain
Following visualisation on colposcopy, what may be done?
If area of abnormal cells is obvious, can have tx
right away (usually LLETZ). If not clear, may need biopsy +/- bring back for tx if required.
