Cervical Cancer Screening Via Self-sampling

Study subjects and sample size. The study will be performed in the Nazarbayev University School of Medicine (NUSOM) in collaboration with other local medical universities and institutions.

This will be a cross-sectional study involving women attending outpatient clinics in Kazakhstani major cities, who will be recruited into the study to validate the HPV self-sampling kits. The project timeline is - January 2025-December 2027. We plan to invite 1000 women for a validation study: all women will complete a questionnaire after self-collection of a smear using kits.

Inclusion criteria: Eligible participants will be recruited from different outpatient clinics in Kazakhstan located in the different regions (western, eastern, northern, southern, and central parts) of the country, and must meet the following inclusion criteria: (1) age - women 18 years and older; (2) Intact uterine cervix (no prior total hysterectomy or trachelectomy); (3) ability to understand and answer questions/surveys in Kazakh, Russian or English.

Exclusion criteria: patients who are (1) younger than 18 years old, (2) women after total hysterectomy (or other surgery, when the uterine cervix is removed), (3) pregnant women, and (4) those who are not able to answer questions in Kazakh, Russian or English will be excluded.

Recruitment process. The recruitment will be done via trained and experienced outpatient gynecologists. After a careful explanation of the study's aims, all women who agreed to participate will be recruited and asked to sign an informed consent form. Further, they will (1) undergo a cervical sampling performed by the gynecologist ("gold standard" sampling), and (2) all women recruited into the study will be provided with different self-sampling kits (Evalyn Brush and Copan self-sampling swab, or Evalyn Brush and BGI Sentis HPV card) and written (picture-based) instruction to use the sampling kits. A patient will have to perform a self-sample based on the instruction and return the kits to the provider.

Sample size. We used the following parameters when estimating the required sample size: alpha = 0.05, sensitivity = 50%, accuracy estimate at 0.05%, and HPV prevalence at 40% [18]. Using the formula for sample size estimation in diagnostic studies [51], we calculated 961 participants, rounding them to 1,000 required sample size. Our goal is to survey 1000 patients to determine the acceptability of the method of self-collection of smears for HPV. With an estimated population the different regions of the country - Astana (1.000.000), Aktobe city (350.000), Almaty (around 2.000.000) - the goal to collect 1000 samples will be achieved. For this purpose, three types of HPV self-sampling kits (Evalyn Brush, Copan self-sampling swab, and BGI Sentis HPV card) will be utilized and compared.

HPV self-sampling kits. For the project purposes different types of self-sampling kits will be used - Evaline Brush, Copan self-sampling swab, the BGI company HPV self-sampling kit.

1. Evalyn Brush (https://www.roversmedicaldevices.com/cell-sampling-devices/evalyn-brush/). The Evalyn® Brush is a reliable self-sampling device for screening for the HPV.
2. Copan Self Vaginal FLOQSwabs (https://www.copangroup.com/product-ranges/self-floqswabs/) is a tube with a cotton swab. It is a comfortable device supporting women taking part in HPV and STI screening campaigns.
3. BGI Sentis HPV self-sampling kit (https://www.bgi.com/global/molecular-genetics/sentis-oncology/bgi-sentistm-hpv-test/). BGI company had established the worldwide first "communi-ty-based screening model using self-sampling HPV test as primary screening".

Surveys Women who agreed to participate in the study and perform HPV self-sampling will be asked to fill two types of questionnaires: 1) patients' socio-demographic (age, education, residence, income) and clinical data (age at menarche, number of children, gynecological and non-gynecological conditions in the past medical history, etc.); 2) and survey to assess acceptability of HPV self-sampling and different self-sampling kits.

The second questionnaire will be filled out by the participants and was adapted from previous studies. The patient questionnaire consists of 17 items (4 items to respond to before self-sampling and 13 - after) and will be used to understand patients' attitudes and acceptability of the HPV self-sampling kit. The survey will be conducted in Kazakh and Russian (or English) languages depending on the preferences of the participants.

To avoid bias, the study participants will not receive any material compensation for participation in the project.

Statistical analyses Ones the HPV testing results and questionnaires collected, statistical analysis will be performed. Statistical analyses will be performed using StataMP 16 (Stata Statistical Software: Release 16. College Station, TX: StataCorp LLC.). To validate self-sampling HPV kits, we will calculate sensitivity, specificity, positive and negative predictive values for each self-sampling HPV kit against the "gold standard" test. In univariate analysis, categorical variables will be expressed as absolute and relative frequencies, while continuous variables will be presented as means and standard deviations. To investigate attitudes and experiences about self-collection of a specimen for cervical cancer screening and understand acceptability of the method, we will use various bivariable testing techniques such as Student t-test or Mann-Whitney U-test, Pearson χ2 or Fisher's exact tests, Kruskal-Wallis test (for multiple group comparisons). Multiple logistic regression model will be used to predict the probability of the outcome based on included variables (p<0.05 or clinically important). The predictive ability of the model will be assessed based on discrimination (AUC in ROC-curve), measure of overall performance (Nagelkerke R2), calibration and decision curve analysis in STATA or R-software.

Ethical consideration The study protocol was approved by the Nazarbayev University Research Ethics Committee (NUIREC); Protocol of approval #621/03102022 (21.10.2022), "Cervical Cancer Screening Using Self-sampling Approach: Validation of Human Papillomavirus Self-sampling Kits Among Kazakhstani Women". This ethical approval was extended in 2024 until October 2025 and is subject to annual renewal.

This study will take place at Nazarbayev University School of Medicine (NUSOM) and different gynecologic hospitals/clinics across Kazakhstan. This research will include patients' self-reported clinical data questionnaire and survey to identify attitudes towards self-sampling and its acceptability. All documents related to the study (application IREC, informed consent forms, and questionnaires) were submitted to NU IREC. Informed consent will be obtained from each subject; all the documents, samples collected and results will be kept confidential. The research team will follow the principles of research ethics, in particular, preventing the fabrication of scientific data, and scientific fraud, which can lead to distortion of scientific data, plagiarism, and scientific misconduct. All patients' data (samples and surveys) will be encoded. To ensure high quality of research and obtained results, data analysis will be conducted using blind methods.

We are aware of some critical points in patient recruitment, which will be the most challenging part of the clinical research. Collaboration with the reliable team established during our previous study ("A molecular epidemiological study to determine the prevalence of oncogenic HPV strains for cervical cancer prevention in Kazakhstan", FCRGP 110119FD4528), time allocated to recruitment, specific characteristics of the population should collectively help to achieve the goals of the project.