Murine, then human testing
A test of CytoPAN on FNA samples from mouse xenografts representing the spectrum of human breast cancer subtypes showed correct and reproducible molecular subtyping that matched well with flow cytometry reports derived from the same tumors.
To determine the clinical utility of CytoPAN, investigators enrolled 68 treatment-naive breast cancer patients who were referred for primary surgery at the Kyungpook National University Chilgok Hospital in Daegu, South Korea. FNA samples were obtained after visualization of breast masses by ultrasound or CT.
Surgical specimens and/or core biopsies were processed by routine pathology for “gold-standard” comparison. FNA samples had sufficient numbers of cells in 63 (93%) patients, with a mean number of cells among them of 1,308 (range, 93-11,985).
CytoPAN analysis correctly identified malignant breast cancer in 55 patients and benign lesions in 5 patients. Three cases were inconclusive because of low numbers of Quad-positive cells for further analysis. The authors pointed out that roughly 20% of biopsy samples in developed countries are deemed “nondiagnostic” because of insufficient cellular contents.
The authors’ summary underscored CytoPAN’s affordable system using cellular rather than tissue specimens, actionable results in an hour, lack of moving parts, multiplexed analysis, and user-friendly interface.
Cancer detection accuracy was 100% (no false negatives or false positives), and receptor subtyping accuracy was 97% for HER2 and 93% for ER/PR.
“Based on these results, we envision prospective clinical trials in remote, decentralized locations,” the authors wrote. The system is being tested further in Botswana.
“I find the data in this paper compelling – particularly for those patients presenting with a palpable mass on clinical exam. ... Certainly in resource-limited settings, this would have significant appeal,” William J. Gradishar, MD, of Northwestern University, Chicago, said in an interview.
Dr. Gradishar explained that, while palpable masses that lead to a diagnosis of noninvasive disease alone are uncommon in the United States because of routine screening mammography, they may still be an issue in other parts of the world.
The authors received funding from the National Institutes of Health, the MGH Scholar Fund, and Robert Wood Johnson Foundation. Some authors disclosed relationships with Akili, Accure Health, ModeRNA, Tarveda, Lumicell, and Noul. Dr. Gradishar reported having no disclosures.
SOURCE: Min J et al. Sci Transl Med. 2020 Aug 5. doi: 10.1126/scitranslmed.aaz9746.