Menstrual blood testing shows promise for HPV screening

Testing menstrual blood for human papillomavirus (HPV) could be a "robust alternative or replacement" for current cervical cancer screening by a clinician, finds a study from China published by The BMJ today.

The researchers say using menstrual blood for HPV testing is convenient and non-invasive, allowing women to collect samples at home, and therefore could offer a practical pathway to expand access to screening.

Certain types of HPV infection can develop into cervical cancer and HPV testing is a key part of cervical screening. But not all women attend screening appointments for reasons including fear of pain, concerns about privacy and stigma, and lack of awareness.

Testing menstrual blood for HPV infection shows promise as a convenient, non-invasive alternative to screening, but evidence is limited.

To address this gap, researchers in China compared the diagnostic accuracy of menstrual blood versus clinician collected cervical samples for detecting high grade (CIN2+ / CIN3+) cervical lesions, which typically require treatment.

Their findings are based on 3,068 women aged 20-54 years with regular menstrual cycles, enrolled between September 2021 and January 2025 at four urban and three rural communities in Hubei Province, China.

Each participant provided three samples for testing: a menstrual blood sample collected using a minipad - a sterile cotton strip attached to the absorbent area of a standard sanitary pad (index test), a clinician collected cervical sample (comparator test), and an additional clinician collected cervical sample for laboratory processing.

A WeChat mobile app (Early Test) was also available to participants to access test results and advice from healthcare providers.

The main outcome measure was diagnostic sensitivity and specificity of the tests. Sensitivity indicates how well a test picks up people who have a disease and specificity indicates how well a test picks up those who don't.

Minipad collected samples for HPV testing showed a sensitivity of 94.7% for detecting CIN2+ which was comparable to clinician collected samples (92.1%).

Although minipad samples showed a lower specificity than clinician samples (89.1% v 90.0%), the negative predictive value - the probability that a person with a negative test result truly does not have the disease - was identical (99.9%) for both collection methods.

There was also no significant difference in positive predictive value - the probability that a person with a positive test result truly has the disease - between both collection methods (9.9% v 10.4%) and referral for further testing (colposcopy) was comparable (10.1 v 9.6 referrals per CIN2+ detected).

Integration with the Early Test mobile app further streamlined result reporting and patient communication, enhancing the feasibility of large scale implementation of screening, note the authors.

These are observational findings so no firm conclusions can be drawn about cause and effect, and the authors acknowledge several study limitations that warrant careful consideration.

However, they say: "The results of this large scale community based study show the utility of using minipad collected menstrual blood for HPV testing as a standardised, non-invasive alternative or replacement for cervical cancer screening."

"The findings of this study support the integration of menstrual blood based HPV testing into national cervical cancer screening guidelines."