Urine-based detection of HPV for cervical cancer screening: towards clinical implementation

KEYWORDS urine, HPV detection, cervical cancer screening, clinical implementation C ervical cancer continues to be a major global health issue, particularly in low- and middle-income countries where access to effective screening and treatment remains limited (1).The primary cause of cervical cancer is persistent infection with high-risk human papillomavirus (HPV) types, especially HPV 16 and 18.Early detec tion of HPV, particularly high-risk strains, is crucial for preventing the progression to cervical cancer.In response to the need for more accessible and efficient screening methods, urine-based HPV testing has emerged as a promising non-invasive alternative to traditional cervical screening approaches, such as Pap smears and HPV DNA testing (2, 3).A recent study by Manjeshwar et al. offers an innovative method for detecting HPV in urine, which could improve access to cervical cancer screening (4).We and other experts have advocated for the standardization of urine-based HPV testing to facilitate its implementation in clinical laboratories (5).Among the key challenges in advancing this technology, sensitivity remains the most critical factor.Sensitivity can be influenced by various variables, such as the volume and timing of urine collection.HPV infects the epithelial cells of the cervix; viral DNA and infected cells are shed into the urine.The first-void urine-the initial portion of urine expelled during urination (typically 20-30 mL)-is often preferred for testing, as it tends to contain the highest concentration of HPV DNA (6).Therefore, standardizing collection protocols across diverse populations and healthcare settings is essential to ensure reliable results.Any variability in sample quality could impact test accuracy, which, in turn, could undermine the test's overall effectiveness.In the study by Manjeshwar et al., 100 mL of first-void urine was collected, but the volume may have diluted the HPV DNA, potentially reducing sensitivity (4).Although a substantial volume (40 mL) was analyzed in their study (4), determining the optimal urine volume for maximum sensitivity remains a subject for further investigation.Another challenge is the standardization of detection protocols.Currently, widely used PCR-based systems, such as Cobas, are employed in clinical laboratories for HPV detection in cervical samples.These PCR systems can also be adapted for use with urine samples (7).However, while urine-based testing can be conducted in low-resource settings, the availability of affordable, reliable diagnostic tests for HPV in urine remains a limitation.Ensuring that diagnostic kits and platforms are accessible and cost-effective in remote or under-resourced regions is crucial for widespread implementation.In the study by Manjeshwar et al., next-generation sequencing (NGS) was employed to optimize the detection of HPV in urine samples (4).NGS is a high-throughput, highly sensitive technique capable of detecting a broad range of HPV types, including rare or hard-to-identify strains.HPV genotyping is directly relevant to clinical applications for the development of cervical cancer screening assays (8).However, despite its sensitivity, NGS remains relatively expensive and requires specialized technical expertise, which may