Circulating cell-free DNA (cfDNA) has attracted attention as a non-invasive biomarker for diagnosing and monitoring various cancers. Given that human papillomavirus (HPV) DNA integration and overexpression of E6/E7 oncogenes are pivotal events for carcinogenesis, we sought to determine if HPV E7 cfDNA could serve as a specific biomarker for cervical cancer detection. We applied droplet digital PCR (ddPCR) to quantify HPV16/18 E7 cfDNA from the serum of patients with cervical cancer, cervical intraepithelial neoplasia, and controls. HPV16/18 E7 cfDNA was highly specific for cervical cancer, displaying 30.77% sensitivity, 100% specificity, and an area under the curve of 0.65. Furthermore, we developed a sensitive isothermal detection of HPV16/18 E7 and the PIK3CA WT reference gene based on recombinase polymerase amplification combined with a lateral flow strip (RPA-LF). The assay took less than 30 min and the detection limit was 5–10 copies. RPA-LF exhibited 100% sensitivity and 88.24% specificity towards HPV16/18 E7 cfDNA in clinical samples. The agreement between RPA-LF and ddPCR was 83.33% ( κ = 0.67) for HPV16 E7 and 100% ( κ = 1.0) for HPV18 E7, indicating a good correlation between both tests. Therefore, we conclude that HPV E7 cfDNA represents a potential tumor marker with excellent specificity and moderate sensitivity for minimally invasive cervical cancer monitoring. Moreover, the RPA-LF assay provides an affordable, rapid, and ultrasensitive tool for detecting HPV cfDNA in resource-limited settings.

Purpose: To assess knowledge, attitudes and cervical cancer screening behavior of Bangkok Metropolitan women. Materials and Methods: Thai women, aged 25-to-65 years old, having lived in Bangkok for 5 years or more were invited to participate in the study. After signing informed consent, all women were asked to complete a self-questionnaire (Thai language) with literate assistance if needed. The questionnaire was divided into 3 parts: (I) demographic data; (II) knowledge about cervical cancer screening; and (III) behavior and attitudes, towards cervical cancer screening. Adequate screening was defined as women who had ≥two cervical cancer screening tests except women aged 25-30 years who may have only one screening, and the last screen was within 5 year or had had regular screening. Results: Of 4,339 women, there were 1,857 (42.8%) with adequate screening and 2,482 (57.2%) with inadequate screening. Significant factors associated with inadequate screening included age < 45 years, pre-menopausal status, family monthly income <625 USD, no reported sexual intercourse, nulliparous, no knowledge, lack of awareness and poor attitudes. Three major reasons provided by women for inadequate screening were no symptoms (54.4%), fear of pain (33.2%), and embarrassment (34.6%). Conclusions: Personal features, knowledge, and attitudes influence screening behavior of Bangkok Metropolitan women. The three most common reasons of women for not undergoinging screening are no symptoms, fear of pain, and embarrassment. These factors should be the focus of attention to improve coverage of cervical cancer screening in Bangkok.

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