"Screen" out hidden dangers, "check" for health: an article to understand cervical cancer screening

Author: Fang Lei, deputy chief physician, the Second Affiliated Hospital of Harbin Medical University

Reviewer: Cui Yulan, Chief Physician, The Second Affiliated Hospital of Harbin Medical University

Cervical cancer is one of the most common gynecological malignancies. In my country, a woman is diagnosed with cervical cancer every 5 to 6 minutes, and a woman loses her life from cervical cancer every 20 minutes.

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1. What is cervical cancer screening?

Cervical cancer screening is a key link in the secondary prevention of cervical cancer. Standardized screening can reduce the incidence and mortality of cervical cancer.

2. What is the significance of cervical cancer screening?

Regular cervical cancer screening can detect precancerous lesions or early cervical cancer at an early stage, so that timely treatment can be given and the patient's life can be prolonged. In addition, screening can also identify high-risk groups and strengthen follow-up to detect lesions in a timely manner.

3. What are the common misunderstandings?

1. Can one screening ensure lifelong worry-free status?

This is a wrong concept. Cervical cancer screening needs to be performed regularly, and it is generally recommended to be performed every 3 to 5 years.

2. Will human papillomavirus infection definitely lead to cervical cancer?

Human papillomavirus (HPV) infection is common, but most infections are transient. Only a few persistent infections with high-risk HPV types can lead to cervical cancer.

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3. Do I still need to undergo cervical cancer screening even if I don’t feel any discomfort?

Yes. HPV infection often causes no symptoms and can remain dormant in the body for many years. The stage when HPV infection causes changes in cervical cells but has not yet infiltrated the cervical stromal cells is called precancerous lesions. Most women will not have any symptoms before developing cervical cancer.

4. Is everything fine if the screening results are normal?

A normal screening result only means that the current cervix is ​​in good condition, but it does not guarantee that there will be no lesions in the future. Therefore, even if the screening result is normal, you should maintain good living habits and undergo regular screening.

4. Things to note before cervical cancer screening

1. Screening should be performed during the non-menstrual period, preferably within 3 to 7 days after the end of menstruation, to avoid interference from blood and mucus and ensure that sufficient cervical exfoliated cells are collected.

2. Avoid sexual intercourse two days before the screening to prevent male semen from affecting the screening results.

3. Do not flush the vagina or use vaginal medications one day before the screening, so as not to affect the collection of cervical exfoliated cells.

4. If the patient suffers from gynecological inflammation (such as vaginitis), treatment should be carried out before screening to ensure the accuracy of the test results.

5. “Timetable” for Precision Screening

1. Screening starting age: 25 years old female.

2. Women aged 25 to 64: HPV nucleic acid testing alone or combined screening once every 5 years; or cytology examination every 3 years.

3. Screening end age: Women over 65 years old (subject to doctor’s opinion)

VI. Screening of Special Populations

1. Screening of high-risk women under 25 years old

The risk of cervical cancer increases for women under 25 years old who have a history of multiple sexual partners, early sexual life, infection with human immunodeficiency virus (HIV), and smoking. It is recommended to screen within 1 year after starting sexual life and shorten the screening interval appropriately.

2. Screening for women who are planning to become pregnant or during pregnancy

Cervical cancer screening during pregnancy is safe and does not pose a threat to the health of mother and child. For women who have never received or have not undergone standardized cervical cancer screening, screening is recommended during pre-pregnancy examinations or the first prenatal examination.

3. Screening of women after hysterectomy

(1) Women who have undergone hysterectomy for cervical precancerous lesions should undergo combined screening every year. If the combined screening is negative for three consecutive times, it can be extended to once every three years for 25 years.

(2) For women who have undergone hysterectomy for benign uterine disease, routine screening is not recommended if there are no suspicious clinical symptoms or signs.

(3) For patients who are unclear whether they have precancerous lesions before cervical resection, combined screening is recommended if there are clinically suspicious symptoms or signs.

4. Screening of immunocompromised people

When screening immunocompromised people, comprehensive considerations such as age, previous screening history, expected survival rate, disease status, and risk factors are required.

5. Screening of women who have received the HPV vaccine

Although the preventive HPV vaccine can reduce the risk of cervical cancer, it does not cover all high-risk HPV types. In addition, people who have had sexual intercourse may have been infected with HPV before vaccination. Therefore, regular screening should still be performed after receiving the HPV vaccine.

VII. Three-step screening process

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1. The first step: liquid-based thin-layer cytology (TCT) and HPV testing

(1) TCT: A special sampling brush is used to collect exfoliated cells for the detection of cervical lesions. It can accurately capture changes in cell morphology and can detect everything from inflammation, precancerous lesions to early cancer cells.

(2) HPV testing: HPV DNA fragments in cervical samples are detected through advanced nucleic acid testing methods. Persistent infection with high-risk HPV is the main cause of cervical cancer. HPV testing helps doctors to gain insight into potential crises in advance.

(3) Combined screening: HPV and TCT tests complement each other, and combined screening can improve the detection rate.

2. Second step: colposcopy

A colposcope is a magnifying device for observing the vulva, vagina and cervix. Through colposcope examination, doctors can more intuitively observe abnormal changes on the surface of the vulva, vagina and cervix.

3. The third step: cervical biopsy

When suspicious lesions are found under colposcopy, the doctor will perform single or multiple biopsies on the suspicious lesions to confirm the diagnosis. Cervical biopsy is the gold standard for diagnosing cervical cancer.

8. How long does it take for HPV infection to develop into cervical cancer?

Early cervical cancer usually has no obvious symptoms, and most cases are discovered during physical examinations. After symptoms appear, most cervical cancers are already in the late stage. Since cervical cancer has a long precancerous lesion stage (usually takes 10 to 15 years), and more than 99% of cervical cancers are caused by HPV. Therefore, during this long period of time, regular screening can detect precancerous lesions or early cervical cancer early, thereby improving the patient's prognosis and reducing the incidence of cervical cancer.

References:

[1] Liu Jiaqi, Li Pengfei, Ji Mei, et al. Investigation and analysis of standardized diagnosis and treatment of cervical cancer based on big data of clinical diagnosis and treatment of cervical cancer in China[J]. Chinese Journal of Practical Gynecology and Obstetrics, 2021, 37(1):5.

[2] Wang Lianhua, Liu Jiahui. The importance and precautions of cervical cancer screening[J]. Man Science (New Health), 2024(6):134-134.

[3] He Chanchan, Zeng Dian, Zhang Yue, et al. Analysis and discussion of the age range for cervical cancer screening in various countries around the world [J]. Modern Preventive Medicine, 2024, 51(4):630-639.

[4] Li Mingzhu, Wei Lihui, Sui Long, et al. Chinese cervical cancer screening guidelines (I) [J]. Chinese Journal of Clinical Obstetrics and Gynecology 2023; 24(4): 437-442.