Cervical Cancer Flashcards
Epidemiology of cervical cancer?
Cancer of the cervix tends to affect younger women, peaking in the reproductive years
Majority of cervical cancers are what types?
80% of cervical cancers are squamous cell carcinoma. Adenocarcinoma is the next most common type. Very rarely there are other types, such as small cell cancer.
What is strongly associated with cervical cancer?
Cervical cancer is strongly associated with human papillomavirus. Children aged 12 – 13 years are vaccinated against certain strains of HPV to reduce the risk of cervical cancer.
What is used to screen for precancerous and cancerous changes to cervical cells?
Cervical screening with smear tests is used to screen for precancerous and cancerous changes to the cells of the cervix.
What is the most common cause of cervical cancer?
The most common cause of cervical cancer is infection with human papillomavirus (HPV). HPV is also associated with anal, vulval, vaginal, penis, mouth and throat cancers. HPV is primarily a sexually transmitted infection.
What types of HPV are associated with cervical cancer?
Type 16 and 18 - responsible for 70% of cervical cancers
These are the strains targeted with the HPV vaccine
Treatment for HPV infection?
There is no treatment for infection with HPV. Most cases resolve spontaneously within two years, while some will persist.
How does HPV cause cancer?
P53 and pRb are tumour suppressor genes. They have a role in suppressing cancers from developing. HPV produces two proteins (E6 and E7) that inhibit these tumour suppressor genes. The E6 protein inhibits p53, and the E7 protein inhibits pRb. Therefore, HPV promotes the development of cancer by inhibiting tumour suppressor genes.
Risk factors for cervical cancer?
Early sexual activity
Increased number of sexual partners
Sexual partners who have had more partners
Not using condoms
Non-engagement with cervical screening
Smoking
HIV (patients with HIV are offered yearly smear tests)
Combined contraceptive pill use for more than five years
Increased number of full-term pregnancies
Family history
Exposure to diethylstilbestrol during fetal development (this was previously used to prevent miscarriages before 1971)
TOM TIP: When you are performing a history in your exams and considering cancer, always ask about risk factors to show your examiners you are assessing that patient’s risk of having cancer. Ask about attendance to smears, number of sexual partners, family history and smoking.
How does cervical cancer present?
Next steps?
Cervical cancer may be detected during cervical smears in otherwise asymptomatic women.
The presenting symptoms that should make you consider cervical cancer as a differential are:
Abnormal vaginal bleeding (intermenstrual, postcoital or post-menopausal bleeding)
Vaginal discharge
Pelvic pain
Dyspareunia (pain or discomfort with sex)
These symptoms are non-specific, and in most cases, not caused by cervical cancer. The next step is to examine the cervix with a speculum. During examination, swabs can be taken to exclude infection.
Where there is an abnormal appearance of the cervix suggestive of cancer, an urgent cancer referral for colposcopy should be made to assess further. Appearances that may suggest cervical cancer are:
Ulceration
Inflammation
Bleeding
Visible tumour
What is cervical intraepithelial neoplasia?
Cervical intraepithelial neoplasia (CIN) is a grading system for the level of dysplasia (premalignant change) in the cells of the cervix. CIN is diagnosed at colposcopy (not with cervical screening). The grades are:
CIN I: mild dysplasia, affecting 1/3 the thickness of the epithelial layer, likely to return to normal without treatment
CIN II: moderate dysplasia, affecting 2/3 the thickness of the epithelial layer, likely to progress to cancer if untreated
CIN III: severe dysplasia, very likely to progress to cancer if untreated
CIN III is sometimes called cervical carcinoma in situ.
TOM TIP: Try not to get mixed up between dysplasia found during colposcopy and dyskaryosis on smear results.
Cervical screening involves?
Smear test - speculum examination and collection of cells from the cervix using a small brush. The cells are deposited from the brush into a preservation fluid. This fluid is transported to a lab where the cells are examined under a microscope for precancerous changes (dyskaryosis). This way of transporting the cells is called liquid-based cytology.
Cervical screening program includes which groups of people at what frequency?
The cervical screening program involves performing a smear for women (and transgender men that still have a cervix):
Every three years aged 25 – 49
Every five years aged 50 – 64
Exceptions to the cervical screening program?
Women with HIV are screened annually
Women over 65 may request a smear if they have not had one since aged 50
Women with previous CIN may require additional tests (e.g. test of cure after treatment)
Certain groups of immunocompromised women may have additional screening (e.g. women on dialysis, cytotoxic drugs or undergoing an organ transplant)
Pregnant women due a routine smear should wait until 12 weeks post-partum
What are potential cytology results?
Cytology results:
Inadequate Normal Borderline changes Low-grade dyskaryosis High-grade dyskaryosis (moderate) High-grade dyskaryosis (severe) Possible invasive squamous cell carcinoma Possible glandular neoplasia