There are two main screening methods for cervical cancer: one is human papillomavirus (HPV) testing, and the other is liquid based thin-layer cell testing (TCT). The former is to check for any abnormal changes in the morphology of cervical cells, while the latter is to check whether cervical cells are infected with HPV virus that can cause cervical intraepithelial lesions or cervical cancer. HPV is the cause, TCT is the result.
HPV testing is a method of detecting the epithelial basal layer cells in cervical secretions to determine the presence of infection. If there is, HPV-DNA positivity can be detected and classified, allowing for early screening of asymptomatic carriers and prevention of precancerous lesions.
High risk individuals should undergo regular HPV testing, such as: ① those who smoke for a long time; ② People with a family history of cervical cancer; ③ People who engage in sexual activity too early; ④ People with multiple sexual partners; ⑤ People who take oral contraceptives for a long time; ⑥ People who have experienced multiple miscarriages and unhealthy lifestyle habits in the past; ⑦ People infected with HIV; ⑧ Previously treated for CIN2, CIN3, or cancer; ⑨ People with contact vaginal bleeding, etc.
According to the level of carcinogenicity of HPV, it is divided into low-risk and high-risk types. Low risk types include HPV6, 11, 42, 43, 44, etc., which often cause benign lesions such as genital warts; High risk types include HPV16, 18, 31, 33, 35, 39, etc., especially HPV16 and 18 are closely related to cervical cancer. However, a positive HPV test result does not necessarily mean cervical cancer. Only with both high-risk HPV infection and persistent infection can it further develop into cervical cancer.
TCT examination uses a liquid based thin-layer cell detection system to detect cervical cells and perform cytological classification diagnosis. If the results are abnormal, vaginal colposcopy is required to obtain cervical tissue for pathological examination to confirm the diagnosis. TCT examination can not only observe precancerous lesions, but also detect microbial infections such as mold, trichomonas, chlamydia, etc.
The TCT test results are mainly divided into the following categories:
① No intraepithelial lesions or malignant lesions (NILM): If the patient has also undergone HPV testing and the result is negative, it indicates that the cervical cells are normal, and regular follow-up is sufficient.
② Atypical squamous cells with unclear meaning (ASC-US): suggesting that cervical cells may have undergone pathological changes. If high-risk HPV infection is present, it is recommended to undergo vaginal colposcopy and cervical biopsy; If not available, a follow-up examination can be conducted 3-6 months later.
③ Cannot rule out atypical squamous epithelial cells with high-grade squamous intraepithelial lesions (ASC-H): suggesting that cervical cells may have precancerous lesions or cancer, but the abnormality of cells is not clear enough for diagnosis, and cervical biopsy under colposcopy can be used for diagnosis.
④ Low grade squamous intraepithelial lesions (LSIL): Indicates abnormal cervical cells and may be a low-grade precancerous lesion, which can be diagnosed through vaginal colposcopy cervical biopsy.
⑤ High grade squamous intraepithelial lesions (HSIL): suggestive of suspected precancerous cells, with a high possibility of developing into cancer, requiring further diagnosis and treatment; It is recommended that patients check for high-risk HPV infection and undergo colposcopy and cervical biopsy as soon as possible.
⑥ Atypical glandular epithelial cells (AGC): Indicates a lesion in the cervical canal cells, and requires colposcopy and cervical canal tissue examination for diagnosis. If necessary, diagnostic curettage or hysteroscopy may be performed to rule out endometrial lesions.
⑦ Squamous cell carcinoma (SCC) or adenocarcinoma: indicating that cervical cells have undergone malignant transformation, timely cervical multi-point biopsy under colposcopy should be performed to further clarify the diagnosis.
In summary, TCT testing can detect cellular abnormalities in cervical precancerous lesions, and HPV, as a supplementary means of TCT in cervical cancer screening, can improve the sensitivity and effectiveness of screening. Only by combining these two results can doctors make an accurate diagnosis.