Cervical cancer is a common malignancy of the female reproductive system and is currently the only cancer that can be prevented by vaccination. Cervical cancer is a cancer closely related to persistent high-risk HPV infection, and its development process generally takes several steps: cervical intraepithelial neoplasia (CIN1→CIN2→CIN3) → cervical carcinoma in situ → early cervical invasive carcinoma → cervical invasive carcinoma, and the whole development process generally takes 15-20 years, so we have enough time and opportunities to detect precancerous lesions of cervical cancer early. It also means the importance of regular screening. Due to the special anatomical characteristics of the cervix, it can be seen through gynecological examination, which makes early detection of cervical cancer possible. 1.When to start cervical cancer screening? The starting age of cervical cancer screening is 21 years old. Women aged <21 years have a low risk of developing cervical cancer, and even if cancer occurs, the possibility of finding early lesions by screening after the age of 21 is high; premature screening may lead to unnecessary tests and treatments, some of which are even harmful and can increase the risk of preterm birth. 2. What are the screening methods for cervical cancer? There are three screening methods for cervical cancer as follows. (1) High-risk human papillomavirus (HR-HPV) test The common clinical method is the second-generation hybridization capture method (HC2 method), but in recent years, the new method cobas 4800 HPV DNA test is recommended internationally to be more accurate and can provide HPV 16 and 18 typing results. Human papillomavirus, abbreviated as HPV in English, is divided into two types: low-risk and high-risk. High-risk HPV is closely related to cervical cancer, especially subtypes 16 and 18 HPV infections are most closely related to cervical cancer. Current studies have concluded that persistent high-risk HPV infection is the primary factor that induces cervical cancer. HPV infection in the reproductive tract is mainly transmitted through sexual intercourse, and the peak age of infection is between 18 and 28 years old, HPV can be repeatedly infected and different subtypes can be repeatedly infected, but not all HPV infected patients will develop CIN or cervical cancer, only persistent high-risk HPV infection is the main risk factor for the development of CIN and cervical cancer. Only about 5% are persistently infected. For adolescent women aged 21 to 29, repeated positive HPV tests may represent recurrent transient infection rather than persistent infection, therefore, screening with HPV testing is not recommended for this age group, and cervical cytology screening is used instead. (2) Cervical cytology Commonly known as cervical smear, the commonly used clinical method is cervical fluid-based cytology (TCT). (3) Colposcopy Colposcopy is a type of endoscope that refers to the clinical use of a magnifying instrument between the naked eye and a low-power microscope to directly visualize lesions of the cervix and lower genital tract under strong light illumination. The magnification of the colposcope as well as the acetic acid reaction test and iodine solution test are used to assess the extent of cervical lesions and to locate biopsies for further pathological examination under direct colposcopic view, which can effectively improve the accuracy of diagnosis. Further colposcopy and, if necessary, localized biopsy are usually required only if the cervical cytology and/or HR-HPV test is abnormal (especially in those positive for HPV subtypes 16 and 18). 3.How to screen women of different age groups for cervical cancer? (1) For women aged 21-29 years, the recommended screening method is cervical cytology alone, once every 3 years. (2) For women aged 30 to 65, the recommended screening method is combined HR-HPV test and cervical cytology once every 5 years, or cervical cytology alone once every 3 years. (3) For women >65 years of age, screening can be discontinued if previous screening results are continuously negative.