August 19, 2022

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Cervical cancer: Mortality rate reduced 63.5% if early screening rate over 40%

Cervical cancer: Mortality rate reduced 63.5% if early screening rate over 40%

 

 

Cervical cancer: Mortality rate reduced 63.5% if early screening rate over 40%.  In areas where the early cervical cancer screening rate is over 40%, the mortality rate is reduced by 63.5%. 

According to studies, if detected through examinations and appropriate treatment, the 5-year survival rate for cervical intraepithelial carcinoma (stage 0) is almost 100%, and the 5-year survival rate for early stage Ia1 cancer is also more than 95%.


Cervical cancer is a malignant tumor that originates in the neck of the uterus. Persistent high-risk HPV infection is the main risk factor for cervical cancer. Cervical intraepithelial tumors undergo mild neoplasia (CIN1), moderate neoplasia (CIN2) and high-grade neoplasia. The change is intraepithelial carcinoma (CIN3) becomes cervical cancer. It takes several years to develop from HPV infection to cancer. 80% of mild and moderate tumors will not develop into cancer, and some will disappear naturally.

 

HPV infections mostly occur in young people in their 20s who have frequent sexual behaviors. Cervical cancer starts at the age of 20, and the age of cervical cancer is the most common in the 30s and 40s. If cervical conusectomy is performed at the stage of high-grade neoplasia and intraepithelial carcinoma, it can preserve the uterus and prevent invasive cancer. This high-grade neoplasia and intraepithelial carcinoma have almost no symptoms. According to reports, if detected through examinations and appropriate treatment, the 5-year survival rate for cervical intraepithelial carcinoma (stage 0) is almost 100%, and the 5-year survival rate for early stage Ia1 cancer is also more than 95%.

Cervical swab cytology is a method used in countermeasure examinations in Japan. The doctor directly confirms the cervix and uses a spatula or brush to extract the cells (wiping). The collected cells are immediately made into diagnostic specimens, and experts trained in cytodiagnostics (cytologists and cytodiagnostics certified by the Japanese Society of Clinical Cytology) use a microscope to observe whether there are abnormal cells. Although the liquid specimen method uses different cell specimen preparation methods, the steps are basically the same as the above. In addition, there is a “self-collection method” in which the subject collects cells by himself. However, because it is difficult to collect cells from the cervix, it is not included in the cervical swab cell diagnosis. This method cannot extract cancer cells and is not suitable for use as a diagnostic method.

 

 

In addition, there are methods that include HPV inspection, such as HPV individual inspection method, HPV inspection and cell diagnosis combined use, and HPV test positive cell diagnosis and re-diagnosis method. HPV test is a method of taking cells from the cervix and checking whether there is HPV infection in the cells. This test method can diagnose HPV infection, but it cannot directly determine whether there is cancer or abnormal formation. HPV inspection is divided into hybrid capture 2 (HC2) method and gene amplification method (PCR method), the latter can diagnose HPV in more detail. The HC2 HPV DNA test is the second product launched by Digene, a molecular diagnostic company headquartered in Maryland, USA (this company was acquired by Qiagen, another German-based gene sequencing instrument manufacturer, for US$1.6 billion in 2007). Generation hybrid capture technology.

HPV examination and cytological examination and use The collected cervical cells are simultaneously subjected to HPV examination and cytological examination. The method of re-diagnosis of the cytodiagnosis for those with positive HPV test requires that the HPV-infected persons who are at risk of cervical cancer be screened out based on the HPV test, and then the cytodiagnosis is performed on such infected persons, that is, to narrow the scope of the precise examination. In addition, the HPV test performed by patients who showed abnormalities after the cytology screening is not an examination, but one of the clinical diagnosis methods, which is an examination method performed within the scope of the diagnosis and treatment.


So far, there are no randomized comparative trials on the effect of cervical swab cell diagnosis on cervical cancer mortality. However, according to most observational studies conducted around the world, if the cervical swab cell method is used for regular screening, the mortality rate of cervical cancer and the incidence of invasive cancer will be significantly reduced, and the mortality rate will be reduced by as much as 80%. According to a 10-year observation report in Japan, the mortality rate has been reduced by 63.5% in areas with an early cervical cancer screening rate of more than 40%, while the mortality rate has been reduced by 33.3% in areas with an early cervical cancer screening rate of about 10%. The sensitivity of cervical swab cytometry, if people who are suspected to be more than positive in cytology are regarded as the object of close examination, 94.7% of intraepithelial carcinoma can be found.

At this time, the specificity that can be judged not to be intraepithelial carcinoma is 98.9%. The diagnostic ability varies greatly from region to region, but for the ability to detect moderate neoplasia, overall there is a sensitivity of 50-80% and a specificity of 70-90%. As for the liquid test method, because it uses almost the same method as the former, the sensitivity and specificity are almost the same as the former for any lesion, so it can be judged that the liquid test method can also reduce the mortality of cervical cancer.

 

The sensitivity of HPV alone to detect moderate or high tumors is more ideal than cell diagnosis, but the HPV method is less effective in terms of specificity. The same applies to HPV examination and cell diagnosis. Compared with the single method and combined use, the cell diagnosis and re-diagnosis method can improve the accuracy of the positive reaction. However, due to the lack of evidence for the impact on overall mortality, it is not recommended for use in countermeasures.

 

In cervical swab cytology, even if there is bleeding due to cell collection, it will not be accompanied by serious pain or risk. However, for mild and moderate tumors that can heal on their own, overdiagnosis may occur. During the close examination, there will be some bleeding when using the magnifying mirror to collect the tissue. High-grade neoplasia and intraepithelial cancer are found in the precise examination, and cervical conus resection can be performed to investigate the progress of the cancer. The miscarriage and premature delivery caused by conus resection have been reported with or without impact. None of them has any effect on pregnancy. Impact report.

 

(source:internet, reference only)


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