Cervical Cancer
Cervical cancer is one of the most common cancers among women in Hong Kong, mainly caused by persistent infection with high-risk Human Papillomavirus (hr-HPV), primarily transmitted through sexual contact. While most infection is asymptomatic and can be cleared naturally, persistent hr-HPV infection can lead to precancerous cell changes, which may subsequently progress to cancer.
Cervical Screening
Options include cervical cytology, hr-HPV DNA test and Co-test (hr-HPV DNA test + cervical cytology). The preparation requires: schedule the examination after menses ends, and avoid vaginal douching, spermicides, vaginal medicines, and intercourse 2 days before testing. Treat abnormal vaginal discharge before screening. The procedure is quick, with minor discomfort but it’s not painful.
FPAHK Cervical Screening Tests
1. Co-test (hr-HPV DNA Test + Liquid-based Cytology)
Benefits: Co-test improves the sensitivity of cervical cancer risk assessment by detecting abnormal cervical cells and hr-HPV at the same time
Target: Recommended for women aged 30 or above who have ever had sexual experience
Sampling: Co-test is done by using the same liquid-based cell sample, there is no additional sampling required
Co-test Results:
|
hr-DNA Test Result |
Cervical Cytology Result | Recommendations* |
|---|---|---|
| Negative | Negative | Indicates normal result and a 5-year screening interval for Co-test is recommended |
| Positive | Negative | Refer for colposcopy or repeat Co-test after a recommended period depending on the genotyping result |
| Negative | Positive | Refer for colposcopy, or repeat Co-test after a recommended period depending on the severity of cervical abnormalities |
| Positive | Positive | Refer for colposcopy |
*According to The Hong Kong College of Obstetricians and Gynaecologists (HKCOG) Guideline on Cervical Cancer Prevention and Screening in 2016
2. Cervical Cytology (Liquid-based Cytology)
Benefits: Cervical cytology detects early abnormal changes in cervical cells, including precancerous cells
Target: Women aged 25-64 who have ever had sexual experience and those aged 21-24 who are at increased risk for cervical cancer
Sampling: A healthcare provider inserts a speculum into the vagina and uses a soft brush to collect sample cells from the cervix, rinse them into a preservation solution. The sample is sent to a laboratory for processing. Reflex hr-HPV test will be performed to triage ASCUS cases
Interpretation: Computer-assisted interpretation of liquid-based thin preparation cervical cytology
| Cervical Cytology Result | Recommendations |
|---|---|
| Negative | Repeat cervical cytology every 3 years after two consecutive normal annual screenings |
| Positive | Retest or further investigation such as colposcopy depending on the severity of cervical abnormalities |
Frequently Asked Questions
What is hr-HPV DNA test?
It detects high-risk HPV types that can cause cervical cancer or precancerous changes. Recommended by WHO in 2021 as one of the cervical cancer screening methods.
Which types of HPV can be tested by FPAHK’s hr-HPV DNA test?
HPV has over 200 subtypes, with about 40 affecting the ano-genital area. Our FDA-approved test detects 14 high-risk types, including HPV-16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66 and 68. Among these, HPV-16 and 18 cause 70% of cervical cancer.
Cervical cytology alone has been used for decades, why adding hr-HPV DNA test now?
Co-test detects both abnormal cervical cells and high-risk HPV simultaneously, improving the sensitivity of screening. It is endorsed by the Hong Kong College of Obstetricians and Gynaecologists (2016 Guidelines for Cervical Cancer Prevention and Screening) and the Cancer Expert Working Group on Cancer Prevention and Screening of the Centre for Health Protection. A local study also showed Co-test enables earlier detection of precancerous lesions and reduces cancer risk through timely treatment.
Why is Co-test NOT recommended for women under 30 years old?
Prevalence of HPV among young women is high, but most of them can clear the infection. Positive tests may lead to unnecessary stress and overtreatment.
Is Co-test 100% accurate?
No screening method is 100% accurate. Even with normal results, watch out for cervical cancer symptoms and see a doctor if needed.
Who should go for cervical screening?
Women aged 25-29 with sexual experience should have regular cytology screening; those 30-64 can have co-test. Screening is advised regardless of HPV vaccination, marital status, frequency of sexual activity, menopause, or sterilization.
Why women who have HPV vaccination still need regular screening?
HPV vaccine protects against several types of hr-HPV but not all, so regular screening is still needed.
What are the risk factors for cervical cancer?
Risk factors include early sexual activity, multiple partners, smoking, weak immunity, a high number of childbirths or early pregnancy, use of oral contraceptives for >5 years (risk normalizes 10 years after stopping), and past sexually transmissible infections. High-risk women should consult a doctor about starting screening before age 25 or more frequent screening.
HPV Vaccine
What is 9-in-1 HPV vaccine? How should the vaccine be given?
- The 9-in-1 HPV vaccine contains Human Papillomavirus (HPV) 6, 11, 16, 18, 31, 33, 45, 52, 58 L1 protein. It prevents genital warts, premalignant genital lesions and cancers affecting the cervix, vulva, vagina and anus as well as head and neck cancers caused by HPV types included in the vaccine.
- Based on the information from the vaccine’s manufacturer:
- People who are 15 years old or above or immunocompromised individuals should receive 3 doses. After the first injection, the second injection will be given 2 months later and the third injection will be given after another 4 months.
- People who are 14 years old or younger only need two doses, so the first injection will be followed 6 -12 months later by the second injection. Currently there is no evidence that further booster is needed.
Can Cervical Cancer be prevented by HPV Vaccine?
- For girls and women aged 9 or above who have not started sexual activities, HPV vaccine can significantly reduce the chance of getting cervical cancer.
- For women who have been sexually active, the effectiveness of HPV vaccine varies. They should discuss with their doctor first before deciding on having vaccination.
- Vaccination is not 100 percent effective in preventing cervical cancer. No matter they have been vaccinated or not, all sexually active women should have regular cervical screening.
Does the vaccination cause any transient reactions?
- The safety of the HPV vaccine is widely accepted by many monitoring agencies in USA, Canada, Europe, and the World Health Organization. Transient reactions after injection include: pain, swelling and redness at the injection site, dizziness, fever, headache, nausea, etc.
- If the problem persists, you should consult a doctor and tell the doctor about your recent vaccination. Please inform your doctor before injection if you have any of the following conditions: allergic reaction to yeast or vaccines; pregnancy; disease of the immune system; difficulties in controlling bleeding after injection, injury or tooth extraction; and any fever or medication taken on that day.
How to prevent Cervical Cancer?
- Prevention of Cervical Cancer takes more than HPV vaccination. Avoid risky sexual behavior by maintaining a stable and monogamous relationship, using a condom every time, and do not smoke or drink alcohol, so that your own immune system can resist the virus.