University develops method for simple blood test-based cancer detection

A University of Houston researcher has developed a new method to detect cancer, potentially simplifying the process to a blood test. The technique, boasting a 98.7% accuracy rate, merges PANORAMA imaging with fluorescent imaging to identify cancer at its earliest stages and enhance treatment efficacy.

This innovative approach allows researchers to examine nanometer-sized membrane sacs called extracellular vesicles (EVs) that transport various cargos such as proteins, nucleic acids, and metabolites in the bloodstream.

Wei-Chuan Shih, Cullen College of Engineering professor of electrical and computer engineering, and his team discovered significant differences in the number and cargo of small EVs between patients with cancer and those without. “We observed differences in small EV numbers and cargo in samples taken from healthy people versus people with cancer and are able to differentiate these two populations based on our analysis of the small EVs,” stated Shih in Nature Communications Medicine. He added that combining PANORAMA imaging with fluorescence imaging enabled them to visualize, count small EVs, determine their size, and analyze their cargo.

Shih first introduced the PANORAMA optical imaging technology in 2020. This technology employs a glass slide covered with gold nanodiscs to monitor light transmission changes and characterize nanoparticles as small as 25 nanometers. PANORAMA stands for Plasmonic Nano-aperture Label-free Imaging.

Supported by the National Institutes of Health, this research focused on counting small EVs to detect cancer. “Using a cutoff of 70 normalized small EV counts, all cancer samples from 205 patients were above this threshold except for one sample,” explained Shih. For healthy samples from 106 individuals, all but three were below this cutoff, resulting in a cancer detection sensitivity of 99.5% and specificity of 97.3%.

The team further tested the detection threshold using two independent sets of samples from stage I-IV or recurrent leiomyosarcoma/gastrointestinal stromal tumors and early-and-late-stage cholangiocarcinoma mixed anonymously with healthy samples. They achieved 100% accuracy.

“With further optimization, our approach may be a useful tool for cancer detection screening in particular and provide insights into the biology of cancer and small EVs,” said Shih.

Shih's research team includes doctoral students Nareg Ohannesian and Mohammad Sadman Mallick; collaborators Steven H. Lin, Simona F. Shaitelman, Chad Tang, Eileen H. Shinn, Wayne L. Hofstetter, Alexei Goltsov; Manal M. Hassan; Kelly K. Hunt from M.D. Anderson Cancer Center; Shih and Lin founded Seek Diagnostics Inc., aiming to commercialize this technology.

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