Revolutionizing breast cancer screening: Biosensor detects cancer with spit tests

By Stephanie Srakocic | Fact-checked by Jessica Wrubel
Published February 28, 2024

Key Takeaways

  • Researchers have developed a handheld device capable of detecting breast cancer by reading biomarkers in saliva.

  • The device was able to distinguish between healthy breast tissue, early-stage breast cancer, and advanced breast cancer during testing.

  • This device has the potential to dramatically reduce the cost and time burden of breast cancer screening.

Researchers from the University of Florida and the National Yang-Ming Chao Tang University in Taiwan have achieved promising results in tests of a tool that would use saliva to screen for breast cancer. In a study published in February, researchers said they were able to detect breast cancer using biomarkers found in tiny samples of spit. This includes the human epidermal growth factor receptor 2 (HER2) biomarker found in 25 to 30% of all invasive breast cancers and the carcinoma antigen 15-3 (CA 15-3) biomarker.[][]

Both biomarkers were used during the testing phase. The device was able to distinguish between healthy breast tissue, advanced breast cancer, and early-stage breast cancer. There were 21 women in the testing group.[]

The tests use a small handheld device where saliva samples are placed on test strips. The strips are treated with antibodies that respond to biomarkers that indicate breast cancer. When the test strips are inserted, pulses of electricity cause biomarkers to respond to antibodies. The machine reads this response, and clear results are displayed in just a few seconds.[][]

The device is portable, and units could cost around $5 each if available. Test strips could cost only pennies; researchers say results are delivered in less than five seconds. That’s a significant savings in both cost and time when compared to current screening methods. Additionally, there’s no exposure to radiation for the patient, and the medical provider doesn’t need any special technology. Researchers hope all these factors could make an especially high impact in areas where access to screening is currently limited, such as developing nations.[] 

Lead researcher Hsiao-Hsuan Wan, from the Department of Chemical Engineering at the University of Florida, and his team have submitted a proposal to the National Institutes of Health to secure funding for additional testing. The team hopes to use a larger test group and to improve the accuracy of their device. They are also seeking partnerships with medical equipment companies who could help manufacture and distribute the device when testing is complete.[] 

Saliva and cancer testing

Researchers have been looking into the connection between saliva and cancer detection since the 1950s. That’s when US Navy Captain Kirk C. Hoerman and a team at Naval Training Center in Great Lakes, IL, set out to find out if the saliva of prostate cancer patients was different from the saliva of those without prostate cancer. The team tested over 200 samples and found a marked difference in the saliva of patients with untreated prostate cancer; it contained increased phosphatase levels.[]

This link is still being studied today. In 2021, the FDA granted an innovative device designation to a prediagnostic tool developed by Viome that uses saliva to detect throat and oral cancer. The test called CancerDetect for Oral & Throat Cancer is now on the fast track for full FDA approval. In 2022, another saliva test for oral cancer was developed by OrisDX.[][]

Breast cancer screening and mortality rates

Breast cancer screenings are associated with a lowered breast cancer mortality rate. In the US, mammograms became routine in the 1980s. Since then, data shows overall nationwide breast cancer mortality fell 42% by 2021. Individual risks also decrease with regular screening. According to the CDC, for women between 50 and 74, screening every two years reduces the risk of breast cancer fatality by 26% when compared to no screening.[][] 

However, current screening relies on expensive imaging equipment. Updating this technology can add to that cost. Even within the US, there are significant disparities in the quality of screening that is accessible throughout the country. For instance, research shows that Black women are less likely than White women to have access to breast cancer screenings that use the most current mammogram technology. Black women are also 40% more likely to die of breast cancer.[] 

In developing nations, this lack of access to screening can present an even greater challenge. In the US, the overall 5-year-survival rate for breast cancer was 91% percent between 2012 and 2019. Belgium has the highest rate of breast cancer diagnosis in the world. The overall five-year-survival rate in Belgium is 90.6%. In Mali, a country with many barriers to accessible screening, notably having only one radiotherapy machine and four dedicated radiologists for the entire country, the 5-year survival rate is 13.6%.[][][][]

Researchers like Wan and his team are hopeful that salvia tests and other new technology can deliver accessible and affordable screenings across the globe. 

“Ultimately, we’ve created a technique that has the potential to help people all around the world,” Wan said. “We are excited about the potential to make a significant impact in areas where people might not have had the resources for breast cancer screening tests before.”[]

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