Several screening methods for cervical cancer

According to the World Health Organization (WHO), there are 450000 new cases of cervical cancer worldwide every year, of which China has 135000 new cases every year, accounting for about one-third of the world. In recent years, with the increase of human papillomavirus (HPV) infection, the incidence rate of cervical cancer has increased significantly and tends to be younger. The latest research shows that due to the long and reversible precancerous stage of cervical cancer, the five-year cure rate of cervical cancer patients has reached 90% after early detection and timely treatment, indicating that cervical cancer is a preventable and curable disease. Therefore, the screening and prevention of cervical cancer are of great significance.

The traditional manual method (Pap smear) was invented by Greek doctor Papanicolaou and began to be used for cervical cancer screening in the 1940s. Due to its simplicity, painless patient experience, and low cost, it is highly suitable for large-scale population surveys and has been in use for nearly half a century, with some places still using it.

Method: Obstetricians and gynecology doctors use a cork scraper to gently scrape and collect exfoliated cells from the cervix, apply them to a glass slide, stain and treat them, and the pathologist observes them under a microscope to make a diagnosis. Disadvantage: The false negative rate or misdiagnosis rate is relatively high.

2. CCT - Computer Aided Film Reading System - Americans have developed a system called the "Brain Neural Network Simulation System" for scanning traditional Pap smears, known as CCT examination. However, statistical studies have shown that the sensitivity of the initial screening of the system is actually lower than that of experienced professionals, so the US Food and Drug Administration (FDA) only approves it for laboratory quality control. After 2000, CCT has been replaced by a new generation of automated cytology scanning systems.

One of the main reasons for missed or misdiagnosis in traditional Pap smear detection using membrane based liquid based thin layer cytology (KCT) is the loss of cells during sampling and poor quality of the smear. In the 1990s, the new Pap membrane based thin layer cytology technology (KCT) emerged.

Method: The doctor places the collected cells into a sample bottle containing cell preservation solution and delivers them to the laboratory. The production process is controlled by a computer program. The main steps include mixing the cells evenly; Cell negative pressure collection; Cell metastasis. Its advantage is that it removes impurities and forms a clear single-layer smear of cells, which can be clearly seen by pathologists, significantly improving the diagnostic rate of cervical cancer, especially precancerous lesions.

In addition, the preservation solution of KCT can also be directly used for human papillomavirus gene detection.

4. Virological testing: High risk detection of human papillomavirus (HPV) gene

At present, data shows that HPV infection is the most common cause of cervical cancer and its precancerous lesions. HPV virus can be found in 99.8% of cervical cancer patients, and the latest approved method for detecting HPV infection in clinical practice is hybridization capture method.

Method: Use a specially designed small brush to collect cells from the cervix, and the patient is not injured or in pain. The accuracy of this method is quite high, but due to its high cost, it is usually only used in high-risk populations.

5. Colposcopy examination: When abnormal cervical cytological smears are found, colposcopy examination is necessary to determine the lesion. If necessary, several pieces of tissue are taken for pathological examination to provide a basis for surgical treatment.

6. Human papillomavirus (HPV) vaccine: As the main pathogenic factor of cervical cancer is human papillomavirus infection, the fundamental method is to use vaccine prevention, including preventive and therapeutic vaccines. In the near future, cervical cancer will become a malignant tumor that humans can comprehensively prevent and eradicate through immunization.