15 - Cervical cancer Flashcards
Ectocervix
lined by non-keratinising
squamous epithelium
Endocervix
lined by mucinous columnar
epithelium
Squamo-columnar junction
The point at which the
squamous and columnar epithelium meet
What causes the position of the squamo-columnar junction to change
Hormonal influences, moved out to ectocervix in young adult
Transformation zone
- Portion of columnar epithelium that is ultimately replaced by squamous epithelium
- Where precancerous lesions and squamous carcinomas develop
Human Papillomavirus (HPV)
- Accounts for more than 99% of cervical cancers
- Common STI
- Infects basal cells present at the transition zone
- Requires damage to surface squamous cells to
give access to immature basal cells - Most infections transient, asymptomatic and eliminated by host immune response
- Persistent infection increases the risk of precancerous lesions and subsequent carcinoma
Risk factors of HPV
- Age at first intercourse
- Multiple sexual partners
- Impaired immune response
- Smoking
- Coexisting infections
- Lack of regular screening
HPV subtypes
- At least 100 types of HPV
- Divided into low and high oncogenic risk categories
High risk types of HPV
HPV 16 and 18, causing dysplasia and cancer. High Grade Squamous Intraepithelial Lesion
Low risk types of HPV
HPV 6 and 11, causing genital warts. Low Grade Squamous
Intraepithelial Lesion
Other body areas which can be affected by HPV
- Anogenital tract
- Oral cavity
- Upper respiratory tract
Clinical presentation of cervical cancer
- Most asymptomatic
- Abnormal pap smear
- Abnormal bleeding or vaginal discharge
- Pain
- Bladder symptoms
Macroscopic findings
- Early lesions visible only on colposcopy
- Focal induration, ulceration, elevated granular area that bleeds on touch
Types of advanced lesions
- Endophytic: ulcerated
- Exophytic: polypoid tumour mass
Cervical cancer subtypes
- Squamous cell carcinoma
- Adenocarinoma
Precursor lesion of squamous cell carcinoma
cervical intraepithelial neoplasia
Precursor lesion of adenocarcinoma
Adenocarcinoma in situ
Uncommon cervical tumours
- Adenosquamous carcinoma
- Direct invasion via malignancies from
other organs (uterus, rectum, bladder) - Metastasis (breast, ovary)
Squamous cell carcinoma
Malignant squamous epithelium invading
through basement membrane into stroma
How is squamous cell carcinoma graded
Graded as well, moderate, or poorly differentiated depending on how easily the
“squamous” nature of the cells can be detected
Adenocarcinoma
- Proliferation of malignant cells showing glandular differentiation
- Usually moderately or well differentiated
- Multiple variants
Spread of invasive carcinoma
- Advanced tumours extend by direct spread to involve adjacent tissues (bladder, ureters, rectum, and
vagina) - Local pelvic and distant lymph nodes
- Distant metastases (liver, lungs, bone marrow etc)
Prognosis and survival
Most patients with advanced cervical cancer die due to local extension of the tumour rather than distant metastases
Treatment of cervical cancer
- Early invasive carcinomas can be treated with cone biopsy only
- Most invasive lesions treated with hysterectomy and lymph node dissection
- Advanced lesions treated with surgery, radiotherapy and chemotherapy
Identifying precursor lesions
- Pap smear
- Colposcopy
- Cervical punch biopsy
- Cone biopsy/LLETZ
Pap smear
- Cells from transformation
zone obtained via
spatula or brush - Smeared onto slide and
stained using Papanicolaou method - Washed into a liquid based medium
- Screened by a scientist
Quadrivalenet HPV vaccine
HPV 6,11,16 and 18
Bivalent HPV vaccine
HPV 16 and 18
HPV Vaccine
- Vaccine prepared from non-infectious virus-like particles
- Induces serum antibodies to HPV
- Protection for up to 5 years
Is routine pap testing still needed
- Vaccination will not protect against all cervical cancers
- Vaccination will not protect against preexisting HPV infection
CIN
Cervical intraepithelial neoplasia
LSIL
Low grade Squamous Intraepithelial lesion
HSIL
High grade Squamous
Intraepithelial lesion
