Cervical cancer is the second most common cancer among Thai women and one of the leading causes of female cancer deaths. It is caused by the Human Papillomavirus (HPV) — a sexually transmitted virus that triggers abnormal cell changes in the cervix, which can slowly develop into cancer over 10–20 years. With vaccination and regular screening, it is largely preventable.
What is HPV and how many strains are there?
HPV is a group of viruses with over 200 known strains. Around 30 strains affect the genital area, including the vulva, vagina, cervix, penis, scrotum, and anus. These are divided into two groups:
- High-risk strains — 14 strains that can cause cervical, vaginal, vulvar, anal, and penile cancer. Strains 16 and 18 alone account for 70% of all cervical cancer cases, followed by strains 45, 31, and 33.
- Low-risk strains — primarily strains 6 and 11, which cause genital warts (condyloma) in both men and women but are not linked to cancer.
HPV spreads through skin-to-skin contact during sexual activity — including vaginal, oral, and anal sex. Both men and women can carry and transmit the virus.
What are genital warts?
Genital warts appear as small bumps or clusters of tissue with a cauliflower-like or comb-like shape. They are usually painless but may cause itching or sensitivity. In women, they most commonly appear around the vulva, near the anus, on the cervix, or inside the vagina. In men, they appear on the genitals and around the anus.
What are the symptoms of cervical cancer?
Early HPV infection has no symptoms. Cancer typically develops 10–20 years after initial infection, during which abnormal cells can be detected through screening.
Signs that cancer may be developing near the cervix:
- Heavy or blood-tinged vaginal discharge, often with an unpleasant odor
- Abnormal vaginal bleeding – between periods, after sex, or after menopause
- Irregular, prolonged, or unusually painful periods
Signs that cancer may have spread to nearby organs:
- Difficulty urinating, pain during urination, or blood in urine
- Diarrhea or blood in stools
- Unexplained fatigue, weight loss, or loss of appetite
- Back pain or leg swelling
- Pelvic pain
Who is at higher risk of cervical cancer?
- Sexual activity before age 18, or multiple sexual partners
- Long-term oral contraceptive use — especially 5–10 years or more
- Three or more pregnancies and deliveries
- History of sexually transmitted infections — chlamydia, gonorrhea, syphilis, or HIV
- Conditions that weaken the immune system
- Smoking
How can cervical cancer be prevented?
HPV vaccination is the most effective early prevention. The vaccine is made from viral protein fragments — it does not cause infection but provides strong protection. There are three types:
- 2-strain vaccine — protects against the two main cancer-causing strains
- 4-strain vaccine — covers strains 6, 11, 16, and 18, protecting against both cervical cancer and genital warts
- 9-strain vaccine — covers strains 6, 11, 16, 18, 31, 33, 45, 52, and 58 for both men and women aged 9–45, offering the broadest protection against cervical cancer, genital warts, and related genital and anal cancers
The vaccine is most effective when given at a young age. It can be given from age 9 onward. Consult a specialist before vaccination.
When should screening begin?
Cervical cancer screening is recommended starting at age 21 — or after first sexual intercourse — and should be repeated every 3–5 years. Those with additional risk factors should also prioritize regular screening. Women should watch for warning signs between screenings: abnormal vaginal bleeding, lower abdominal pain, or unusual discharge.
After age 65, women with no history of infection or abnormal results and no other risk factors may no longer need routine screening — but should consult their doctor.
If I have had the HPV vaccine, do I still need screening?
Yes. The vaccine protects against strains 16 and 18 with around 90% effectiveness against cervical cancer — but not against all strains. Regular screening remains essential to detect abnormalities from other HPV strains or unrelated causes.
How to prepare for a Pap smear
- Avoid sexual intercourse for 24–48 hours before the test
- Schedule the test 10–20 days after your last period — not during menstruation
- Avoid vaginal creams, douches, or suppositories for 48 hours beforehand, or inform your provider of any medications in use
- No need to shave or fast before the examination
- Rest well the night before
Cervical cancer is serious — but it is one of the most preventable cancers. HPV vaccination combined with regular screening every 3–5 years gives women the strongest possible protection.
For appointments or consultations, contact the Women’s Health Center at Bangkok Hospital Pattaya.
Reference:
Cervical Cancer: Causes, Symptoms, Diagnosis & Treatment (clevelandclinic.org)
