Scimex: US researchers have developed a rapid and reliable cancer screening test which can be used with a smartphone. The proof-of-concept study showed the device, which would only cost $1.80 per diagnosis, could accurately screen for cervical cancer and human papillomavirus (HPV). A proof-of-concept study demonstrates the feasibility of rapid and cost-effective cancer diagnosis at points of care. Digital holography can help perform rapid, reliable, and unencumbered cancer screening at points of care, particularly in resource-poor settings. Ralph Weissleder and colleagues developed an assay called “digital diffraction diagnosis” based on computational analysis of diffraction patterns of molecularly tagged beads that bind to cancer markers found in patient samples.
A plastic module fitted with a light source, mini-lens, and
sample insert is snapped snugly atop the camera of a smartphone, which
records and uploads patterns from the beads to a remote server,
furnishing a preliminary diagnosis within 45 min. The authors tested the
assay’s utility for cervical cancer screening and human papillomavirus
(HPV) detection. The authors used beads that bind to cells labeled with
antibodies against cervical cancer-associated markers, and determined
average bead counts per targeted cell (nbead) for cervical
samples from 25 patients with abnormal Pap smears; the samples were
separately identified through conventional pathology as “high risk,”
“low risk,” or “benign.” Using nbead as a diagnostic parameter,
the authors grouped the samples into high-risk versus low-risk/benign
categories, with a sensitivity of 100% and specificity of 92%. The assay
also helped detect attomole ranges of HPV DNA in patient samples.
According to the authors, the assay, which currently costs $1.80 per
diagnosis, demonstrates the feasibility of a smartphone-based diagnostic
approach in resource-limited settings.