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- Informtion
- Actual information
- Cervical cancer screening
Cervical cancer screening
January 2022 has been declared Cervical Cancer Awareness Month on the planet. Why? Because despite the fact that cervical cancer (hereafter referred to as CRC) is a preventable disease, despite the fact that it is curable if detected early and adequately treated, it remains one of the most common cancers and causes of cancer deaths in women worldwide.
What is RSM? It is a malignant tumor caused by the human papillomavirus (hereinafter HPV) - serotypes 16,18,31,33,35 and some others. HPV causes not only RSM, but also cancer of vulva, vagina, penis, oropharynx, rectum. The development of RSM begins with the introduction of HPV into the surface cells of the cervical epithelium and their subsequent infection. Someone's body eventually defeats the virus, and someone is less lucky, and against the background of a long (it is believed that at least two years) existence of the virus in the cervical epithelium develops precancer (CIN I, CIN II, CIN III), and then cancer. The process of carcinogenesis is long, it takes from 10 to 40 years, reducing in some cases to 2-4 years. The disease is often completely asymptomatic and manifests itself only in far advanced stages.
In 2020, 604 thousand women worldwide were diagnosed with cervical cancer and 342 thousand of them died. In the hope of victory, the experts of the World Health Organization have developed a strategy with the conditional name “90-70-90”-Global Strategy to accelerate the elimination of cervical cancer. In this document, the WHO assumes the achievement of three intermediate targets:
- complete HPV vaccination of 90% of girls by age 15 (in countries where HPV vaccination of children has long been implemented and is part of the national vaccination calendar, the incidence of cervical and other HPV-associated cancers has decreased by more than 80%);
- High quality screening (i.e. cytology, preferably liquid + HPV screening) for 70% of women at age 35 years and again at age 45 years;
- Providing treatment to 90% of women diagnosed with cervical disease
If every country achieves these goals by 2030, cervical cancer will theoretically cease to exist in the next century.
The basis for early detection of precancerous cervical diseases (dysplasias) and microinvasive cervical cancer is screening, i.e. regular oncoprophylactic examinations with cytologic examination of a vaginal cervical scraping. The method is based on a microscopic examination of the structure of cells. The accuracy of cytologic examination is variable and depends on such factors as the method of material collection, the technique of cytologic preparations, and the qualifications of the cytologist who stains and examines the smear.
The sensitivity of the cytologic method in detecting precancerous lesions and RSM varies between 60-95%. The informativeness of the method depends 70% on the quality of material collection. Do you realize how big a role the human factor plays here? Currently, there are several methods of cytologic preparation:
- The traditional method is the application of cellular material obtained by scraping the cervix onto a dry, degreased slide. The obtained preparations are dried in the air and sent to the laboratory, where the material is stained and examined under a microscope by a cytologist. In the Republic of Belarus, a cervical smear for cytologic examination is stained by Romanovsky-Giemsa staining. Most countries use the Papanicolaou staining system of microscopic preparations - Pap-test.Disadvantages of the method: depends on the correctness of the smear and on the quality of staining, it is not always possible to collect a sufficient amount of material (cells), only part of the cells are applied to the glass (some remain on the brush, which is used to collect the material), often in the smear fall blood cells, bacterial cells, which can distort the result, also possible contamination when drying the material on the glass.
- Liquid cytology is a method of preparing preparations from cell suspension. The main difference between the method and the traditional one is that, firstly, a special cytobrush is used, which allows to take cells simultaneously from the cervical canal and from the outer part of the cervix. This is fundamentally important. Secondly, the obtained material together with the brush is placed in a liquid medium that stabilizes the cells. The samples are centrifuged and cyto-preparations are prepared from them, which are represented by “washed cells”. When preparing liquid cytology smears, inflammatory elements, mucus, and red blood cells are removed from the sample, allowing the cells to be examined more closely and abnormal cells to be detected more reliably. Other advantages: the possibility of performing a repeat smear; the possibility of performing HPV DNA detection tests; testing for the expression marker p16ink4a, which is produced in the presence of HPV.
Before taking a test for cytologic examination from the cervix, certain rules should be followed:
- It is recommended to take the test outside of menstruation;
- It is necessary to abstain from sexual intercourse 1-2 days before the examination;
- Do not use spermicides, lubricants, vaginal suppositories or creams the day before the examination (two days before);
- If an examination with smear for cytology and transvaginal ultrasonography is planned, the first examination should be smear and only then ultrasonography;
- Smear collection is performed before dilated colposcopy and bimanual examination;
- Swabs may not be taken under adapted conditions (at home, in bed, with a finger, etc.). Swabs are taken only when the patient is lying on the gynecological chair.
How often to get screened for cervical cancer.
The frequency of cytologic examination of cervical material depends on each specific situation and is determined by an obstetrician-gynecologist. However, there are general recommendations. According to the recommendations of the Ministry of Health of the Republic of Belarus, cytologic examination of cervical smear should be performed annually for all women over 18 years of age who are sexually active (Resolution of the Ministry of Health of the Republic of Belarus of 19.02.2018 № 17 on the approval of the clinical protocol “Medical surveillance and medical care for women in obstetrics and gynecology”).
According to the clinical guidelines “Cervical intraepithelial neoplasia, erosion and ectropion of the cervix (31.05.2021)” it is recommended to perform cytologic examination of cervical smear for all women aged 21 to 65 years at intervals of 3 years in order to detect precancerous diseases of the cervix. It is recommended that all women between the ages of 30 and 65 should be tested for all high-risk HPVs (those most likely to cause RSM) to identify their risk group for precancer and RSM. In simple terms, for women aged 21-29 years, cytology/liquid cytology every 3 years, and for women aged 30-65 years, the preferred option is co-testing (cytology/liquid cytology and HPV test) every 5 years (in HPV negative women) and annually in HPV positive women.
Abnormal cytology results - ASCUS with HPV of high carcinogenic risk, ASC-H, LSIL, HSIL - are an indication for colposcopy, the results of which determine the need for a cervical biopsy. Colposcopy is also indicated for anyone infected with HPV types 16 and/or 18, regardless of cytology results.
One last thing I would like to remind you of. To date, RRMS is the only cancer that can be prevented by vaccination. Vaccination is indicated for all girls from the age of 9 until the beginning of sexual life, as well as for women up to the age of 45 (in the absence of HPV infection or after surgical treatment of cervical diseases). There is currently a choice of three vaccines.
Cervarix - protects against the two most “evil” types of HPV (16 and 18). About 70% of RRMS cases are associated with these types of virus. The vaccine can be given to girls and boys aged 9-14 years (2 doses, each 0.5 ml. The second dose of the vaccine is administered between the 5th and 7th months after the first dose or 3 doses of 0.5 ml at 0-1-6 months). If the child is already 15 years of age at the time of vaccination, three doses should be administered over the course of a year on a 0-1-6 month schedule.
Gardasil - protects against four types of HPV: 16 and 18 (highly oncogenic) + 6 and 11 (cause acute condylomas). Girls and boys aged 9-13 years are given two doses of the vaccine (administer and repeat after 6 months). From 14 years of age, the vaccination regimen consists of 3 doses of 0.5 ml on a 0-2-6 month schedule.
If the child has already begun to live a sexual life, the vaccination is carried out three times, regardless of age.
A new vaccine called Gardasil-9, which protects against 9 types of HPV, has been authorized in the United States since December 2014. The vaccine prophylaxis regimen will be similar.
However, these vaccines are not currently available in the Republic of Belarus.
In our women's clinic you can take liquid cytology (the cost of the service is 51.80 rubles) and undergo colposcopy.
Take care and be healthy!
Obstetrician-gynecologist(Head of Women's Clinic) A.S. Shkarupa.