Abstract
Researchers have developed a rapid, automated point-of-care image cytometry system that accurately detects and categorizes breast cancer. The technique shows promise as a more affordable, less invasive alternative to biopsy that could be especially useful in developing countries and remote settings.
Researchers have developed a rapid, automated point-of-care image cytometry system that accurately detects and categorizes breast cancer. The technique, which uses fluorescence-based imaging to analyze antibodies in samples obtained by fine-needle aspiration (FNA), may offer a more affordable, less invasive alternative to biopsy—something that is especially needed in developing countries and remote locations.
Investigators first validated the test—dubbed CytoPAN—in cell lines and mouse models, demonstrating that it could diagnose breast cancer and identify receptor subtypes in 1 hour using only 50 harvested cells. They then conducted a prospective study involving 68 patients newly diagnosed with breast lesions who were referred for primary surgery (Sci Transl Med 2020;12:eaaz9746). Overall, the test had a 100% accuracy rate for detecting cancer. It had accuracy rates of 96% for detecting HER2 expression and 93% for detecting estrogen receptor and progesterone receptor—key biomarkers linked to breast cancer.
“Several diagnostic technologies have shown the potential to be developed into point-of-care versions for use in resource-limited settings, but, in practice, the number of viable options is much smaller, given the constraints of cost, accuracy, complexity, and practicality,” says first author Jouha Min, PhD, of Massachusetts General Hospital in Boston. Compared with a breast biopsy in East Africa for $100 or in East Asia for $500, CytoPAN is much more affordable—just $10, she says.
“Such a test has high potential value in remote locations and parts of Africa and India, where women often present with advanced stages of cancer,” says Savitri Krishnamurthy, MD, of The University of Texas MD Anderson Cancer Center in Houston, who was not involved in the study. “It' s not perfect, but it is a very good beginning and should be tested further in order to bring it to the field as quickly as possible.”
The test should also be explored in developed countries as a faster, less invasive diagnostic alternative to biopsy, she says. However, one limitation of using FNA for diagnosis of primary breast masses is that it cannot distinguish between invasive tumors and in situ HER2-positive cells.
In the United States and other countries with established healthcare systems, “management of breast cancer is very sophisticated, so just knowing it' s cancer is not enough,” says Krishnamurthy. “The majority of patients who present with mass-like lesions have invasive tumors, but you can run into problems because only 20% to 25% of invasive carcinoma is HER2-positive.”
Still, FNA may be a viable alternative given the large number of core biopsies performed in developed countries. These biopsies are associated with complications and require time-consuming, multistep analyses that can delay diagnosis. Further, only about 20% of biopsies are positive, translating to about 1.3 million unnecessary biopsies per year in the United States alone, Min says.
“We were able to accurately diagnose breast cancer with relatively few harvested cells—which is important because not all FNAs yield equally rich cellularity,” she says. The researchers plan to conduct further testing of CytoPAN in the United States and developing countries. They will also explore other potential applications, including selecting patients for drug trials and analyzing noncancer concerns such as hepatocytes in liver disease. –Janet Colwell
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