DNA testing makes cervical cancer no longer a problem

Many people think that DNA testing is paternity testing, but it turns out that it is not that simple. DNA can be used in many aspects, such as detecting whether a person has cervical cancer. Cervical cancer is an extremely harmful disease. If discovered in the early stages, it may be cured, but in the late stages it is generally incurable. The emergence of DNA testing has reduced the missed diagnosis rate of cervical cancer and improved its accuracy.

1. DNA testing reduces the rate of missed diagnosis. Cervical cancer screening is divided into three stages: exfoliative cytology testing, electronic colposcopy testing and histopathology testing. There are currently three methods for exfoliative cytology testing: Pap smear, liquid-based thin layer technology (TCT), and cell DNA ploidy quantitative analysis technology.

The cell DNA ploidy quantitative analysis technology can grasp the characteristics of normal cell cycle changes by measuring the DNA content in the cell nucleus, thereby detecting malignant tumor cells at an early stage. The detection rate increased from less than 46% in TCT to 95%. Traditional cervical cancer screening technologies, such as TCT, can only detect cervical cancer when cell morphology changes.

In addition, the superiority of using DNA technology is also reflected in the fact that most gynecologists believe that those with smooth cervix do not need to undergo cervical cancer screening, and only pay attention to moderate to severe cervical erosion. In fact, the occurrence of cervical precancerous lesions is not proportional to the degree of cervical erosion.

2. DNA testing improves accuracy. The sampling method and slide preparation of cell DNA ploidy quantitative analysis technology are the same as those of the traditional method, but the staining and slide reading are different. TCT is Papanicolaou-stained and manually read, while DNA is Feulgen-stained and automatically read, thus overcoming the visual fatigue caused by TCT manual detection technology and the differences in diagnostic tools.

Since the dye specifically stains DNA, the depth of the color represents the DNA content; the depth of the color can be converted into optical density values, and the total amount of cellular DNA is the sum of the optical density of all pixels. The value obtained by comparing the DNA content of the measured cells with that of normal cells is the DNA index (DI). When DI=1, it is a normal cell; when DI is between 1-2, it is a small number of cells in the proliferation stage, most of which are inflammatory cells or cells infected with HPV (human papillomavirus); when DI≥2.5, it is DNA positive and needs to be followed up and re-examined; and when DI≥4.5, it is a tumor cell.