Academic Article, November 2025
Cervical Cancer Screening
Chainarong Sillapasa, M.D.
Asst.Prof. Natacha Phoolcharoen, M.D.
Division of Gynecologic Oncology, Department of Obstetrics and Gynecology,
Faculty of Medicine, Chulalongkorn University, Thailand
Cervical Cancer Screening
Cervical cancer is one of the most preventable cancers in women. It usually develops slowly, starting from abnormal cells in the cervix, which is the lower part of the uterus (womb). Most cervical cancer cases are caused by persistent infection with the human papillomavirus (HPV). When HPV stays in the body for many years, it can cause cervical dysplasia (abnormal cell changes), which may eventually turn into cancer if not treated.
Cervical cancer remains a significant cause of cancer death among women worldwide, despite being largely preventable. There are two key ways to prevent it: HPV vaccination and cervical cancer screening. HPV vaccination, when given before HPV exposure, can prevent up to 90% of cervical cancers. Screening helps detect abnormal cells early—before they turn into cancer—and these cells can then be treated. Because it often takes many years for cervical cancer to develop, there is a long window of opportunity for early detection and intervention. This is why regular cervical cancer screening is very important, even if you feel completely healthy.
What Causes Cervical Cancer?
Most cervical cancers are caused by a virus called Human papillomavirus (HPV). HPV is very common, and most people get it at some point in their lives through sexual contact. In most cases, the infection goes away on its own. But if it stays in the body for many years, it can cause changes in cervical cells that may lead to cancer.
Because these changes happen slowly over many years, regular screening helps find and treat them early, before cancer develops.
What Is Cervical Cancer Screening?
Cervical cancer screening is a simple test to check for HPV infection and abnormal cell changes in the cervix. Its purpose is not to diagnose cancer, but to detect early precancerous changes—before they develop into cancer.
There are three main types of screening:
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Pap Smear (cervical cytology): A sample of cervical cells is examined under a microscope to look for abnormal (precancerous) cells.
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HPV Testing: This test looks for high-risk types of HPV that are more likely to cause cancer.
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Co-testing: This combines both Pap and HPV tests and is often used for women aged 30 and older.
Who Should Get Screened and When?
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Under 21: No screening needed
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21–29 years: Pap test every 2 years
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30–65 years: Pap test every 2 years or HPV test every 5 years or Co-testing every 5 years
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Over 65: Screening can be discontinued if screening results over the past 10 years have been normal and there is no history of serious precancerous abnormalities.
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Had hysterectomy (cervix removed): No screening if no history of cervical cancer or precancer
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Women who received the HPV vaccine still need to be screened, because the vaccine does not protect against all HPV types.
What Happens if a Test Is Abnormal?
An abnormal screening result does not mean you have cancer. It means there are some cell changes that need to be checked more closely.
The doctor may recommend:
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Colposcopy: A closer examination of the cervix using a special microscope.
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Biopsy: A tiny piece of tissue is taken and examined to confirm if there are precancerous changes (called CIN – Cervical Intraepithelial Neoplasia).
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Treatment: If necessary, the doctor may remove or destroy abnormal cells using simple procedures such as freezing (cryotherapy), heat (thermal ablation), or electrical loop (LEEP). These treatments are usually quick, safe, and successful.
Self-Collection HPV Testing: A New Option
Many women feel uncomfortable having a Pap test. Now, in many places, women can collect their own sample using a swab, either at home or at a clinic. Research shows that self-collection is safe, accurate, and highly accepted, especially among women who do not regularly go for health check-ups.
Key Messages
– Cervical cancer can be prevented through regular screening.
– Screening can find early cell changes that can be treated before cancer develops.
– There are simple, safe, and effective tests like Pap smear and HPV testing.
– Women should follow age-based screening guidelines, even if they feel healthy.
– New options like self-collection make screening easier and more comfortable.
– Screening saves lives.
You may feel healthy—but screening helps keep you that way.
