9. Cervical cancer screening Flashcards
Is carcinoma of the cervix a preventable disease?
Yes
Up to 90% of cervical CAs are what? (2)
- squamous cell carcinomas and the remainders are adenocarcinomas
- Rarely, cervical CAs have features of both squamous cell carcinomas and adenocarcinomas (i.e., adenosquamous carcinomas).
How to detect abnormal cells on the cervix?
The Pap cytologic test (“Pap test”) is the only way to
Describe Epidemiology of Cervical Cancer (6)
- Cervical CA is the second most common CA in women < 50 yr.
- The median age at Dx of cervical CA is 47 yr.
- The median age at death from cervical CA is 60 yr.
- The 11th most common CA in women and 13th most common CA-related cause of death.
- From 1981 to 2002, the incidence of cervical CA ↓ by approximately 50% in Ontario, due to Pap smear screening.
- Other causes for abnormal Pap smears, other than the HPV virus, are unknown
Name HPVsubtypes according to risk
- Low risks: 6, 11, 41, 44
- Intermediate risk: 31,33,35
- High risk: 16 ,18 ,45 ,56
Describe: HPV transmission (3)
- HPV is transmitted sexually and is the most common STI.
- Condoms do not fully protect against transmission of HPV.
- HPV can be transmitted without penetration.
Describe 1° Prevention of Cervical CA (4)
- Pap smear: the mainstay of screening for precancerous lesions
- HPV vaccine
- Colposcopy
- Rx of precancerous lesions
Name RFs for Cervical CA (10)
- HPV infection with high-risk subtype
- First intercourse at a young age (early coitarche)
- Multiple sexual partners
- Cigarette smoking
- Multiparity
- Long-term use of OCP (inconclusive evidence)
- Immunocompromised status
- Low socioeconomic status
- High-risk sexual partners (i.e., partners whose previous sexual contacts have developed cancerous or precancerous lesions of the cervix)
- Presence of other STIs
Describe Epidemiology HPV (5)
- HPV is one of the most common STIs.
- 75% of Canadians have had one or more HPV infections.
- 95% of squamous cell carcinomas have HPV oncogenic types as do 60% of cervical adenocarcinomas.
- There are 20 HPV types that have been identified as carcinogenic.
- Types 16 and 18 are found most commonly in malignant lesions.
Name types of cervical Pap smears (2)
- Liquid-Based Smear
- Traditional Pap Smear
Describe: Liquid-Based Smear (2)
- Specimen is collected by wiping cells from the cervix and endocervix.
- The cells are suspended in liquid to remove blood and mucus.
- Decreased unsatisfactory Pap test results, but increased cost. Evidence so far shows equivalent clinical outcomes.
- Improved Dx of low and high grades SIL
- Can be used to identify HPV subtypes
Describe: Traditional Pap Smear (3)
- A wooden spatula is used to wipe cells from the surface of the cervix.
- A brush is used to wipe cells from the endocervical canal—(may cause bleeding; should be avoided in pregnancy).
- These cells are spread onto a slide that is fixed for cytologic exam.
True or False
The liquid-based cytology screen has been found to be less sensitive and is associated with more unsatisfactory specimens.
False
The liquid-based cytology screen has been found to be more sensitive and is associated with fewer unsatisfactory specimens.
The transformation zone undergoes transformation from glandular cells to what? (1)
squamous cells (i.e., metaplasia).
What are the most susceptible site for infection by HPV, and subsequent development of cervical CA?
Areas of active metaplasia
When should population screening for CA start? (3)
- There are slight differences among each province
- Should begin within 3 yr of initiating sexual activity or over age 21, whichever is later
- Should be conducted annually until three consecutive negative Pap tests
Describe: Pap smear descriptive conventions (Figure)
Name Pap smear result possibilities (12)
- Unsatisfactory/inadequate sample
- Normal
- Benign atypia (infection, reactive Ds)
- Cervical Intraepithelial Neoplasia (CIN)
- Atypical Squamous Cells - Uncertain Significance (ASCUS)
- Atypical Squamous Cells - Possible HSIL (ASC-H)
- Low-grade Squamous Intraepithelial Lesion (LSIL)
- High-grade Squamous Intraepithelial Lesion (HSIL)
- Carcinoma in situ (CIS)
- Atypical Glandular Cells of Uncertain
- Significance (AGUS)
- Invasive cervical cancer (rarely)
Name these structures
Describe Approach to cervical CA screening (Figure)
Describe frequencies of pap tests (4)
- continue screening q2–3 yr
- should continue until the age of 69 yr, if there has been adequate screening over the past 10 yr
- If there has been no Pap smear for 5 yr, begin annual Pap tests until three consecutive negative Pap tests, then should continue q2–3 yr
- Discontinue screening at age 70 if > 3 normal Pap tests in the last 10 yr
Describe: CA Screening in Special populations (5)
- Women with HIV/immunocompromised should receive annual screening.
- Discontinue screening for women who have undergone a total hysterectomy for benign reasons and no Hx of cervical dysplasia or HPV.
- Women who have undergone a subtotal hysterectomy (i.e., cervix intact) should continue routine screening.
- Screening frequency in pregnancy is the same as in nonpregnant women.
- Women who have sex with women should follow the same screening protocol as women who have sex with men.
Pap smear carries a false-negative rate of __% for invasive CAs.
15% to 40%
Colposcopy provides magnification and illumination of the cervix to do what? (3)
- Further assess abnormalities on the cervix
- Confirm Dx by biopsy
- R/O invasive disease
- F/U after Rx
Describe colposcopy procedure (4)
- Magnification to first inspect the transformation zone visually, then after application of 3% to 5% acetic acid, then Lugol solution
- Biopsies are performed of abnormal-appearing epithelium.
- Colposcopically directed biopsies carry an accuracy of 85% to 95% .
- Endocervical curettage can be performed to R/O dysplasia within the cervical canal.
Name: HPV Vaccine (1)
Gardasil
The quadrivalent HPV vaccine protects against what HPV type? (4)
types 6, 11, 16, and 18.
The quadrivalent HPV is given when? (2)
- at zero, 2 mo, and 6 mo intervals.
- It is most effective when given before the onset of sexual activity.
National Advisory Committee on Immunization (NACI) recommends immunization for HPV for who? (6)
- For the prevention of cervical CA, adenocarcinoma in situ (AIS), vulvar, vaginal, anal CAs and their precursors, and anogenital warts:
- Females 9 through 26 yr of age
- For the prevention of anal intraepithelial neoplasia, anal CA, and anogenital warts:
- Males between 9 and 26 yr of age
- May be administered to females or males over 26 yr of age
- Not recommended < 9 yr of age as no immunogenicity or efficacy data are available in these groups
Should women who receive the vaccine should continue to get screened regularly for cervical CA?
Yes, since they may still be exposed to or infected with other types of HPV.
Peak incidence for cervical CA begins when? (1)
at 45 yr.
Name stages of cervical CA (5)
- 0: CIS, preinvasive carcinoma No stromal invasion
- I: Invasive carcinoma con ned to the cervix
- II: Extends beyond the cervix but not onto the pelvic wall ± upper 2/3 of vagina
- III: Extends to the pelvic wall or involves the lower 1/3 of the vagina
- IV: Extends beyond true pelvis, or has clinically involved the mucosa of the bladder or rectum
Describe RX of stage 0 Cervical CA (4)
Localized Rx:
- cryotherapy
- LEEP
- laser Rx
- conization
Describe RX of stage 1 Cervical CA (1)
Conization or radical hysterectomy ± radiation (Depending on lesion size and patient preference)
Describe RX of stage 2 Cervical CA (1)
Radiotherapy± concurrent chemotherapy
Describe RX of stage 3 Cervical CA (1)
Radiotherapy± concurrent chemotherapy
Describe RX of stage 4 Cervical CA (1)
Radiotherapy± concurrent chemotherapy
From the detection of cytologic abnormalities to invasive CA takes how many years? (1)
Invasive carcinoma of the cervix is usually preceded by what? (2)
- a spectrum of preinvasive disease, which can be detected by a Pap smear.
- It usually takes up to 10 yr for abnormal cells to turn into CA.
