First introduced in 2014, the Clinical Chemistry Hot Topics Symposium immediately became a must-attend event at the AACC Annual Scientific Meeting & Clinical Lab Expo. This popular session focuses on topics and papers that have been highly cited the previous year. At this year’s 68th AACC Annual Scientific Meeting & Clinical Lab Expo, the conversation on August 2 will be about the use of circulating tumor cells (CTCs), cell-free DNA (cfDNA), and microRNA (miRNA) for diagnosing cancer.

We asked the speakers, Rossa Chiu, MBBS, PhD, of the Chinese University of Hong Kong, and Samuel Sia, PhD, of Columbia University, for their thoughts on these emerging technologies.

“At this stage, microRNAs are cheap to analyze but they are non-specific,” Chiu said. In other words, the same microRNA could be elevated for a number of diseases. It is also technically challenging to isolate CTCs, she continued, and the isolation protocols can be quite expensive. Thus, she said, CTCs tend to be associated with more advanced stages of cancer.

The science is further along when it comes to analyzing tumor-derived cfDNA, according to Chiu. “The detection of gene targets that influence therapy have been adopted clinically in some areas,” she said, including EGFR mutation detection for non-small cell lung cancer management.

“As CTC isolation techniques mature in the future,” she concluded, “they will provide a source of tumor DNA that is pure, without interference from non-tumor DNA.”

Yet if such tests are to be commercially successful, the information must make a difference in patient survival and management through earlier diagnosis or better prediction of therapeutic response, and still be cost-effective. “It is too early to tell at this stage [if this will occur],” she said, “because most work is currently focused on method development while studies that address clinical efficacy are just beginning to emerge.”

Sia, who created a microfluidic chip that tests blood samples for multiple diseases and is practical for use in poor countries, predicted such techniques will be “critical” for bringing diagnostic methods to settings like pharmacies, physicians' offices, and the general consumer.

Not all methods will need to be in these types of settings, he continued, “but increasing access to these techniques will propel forward preventative health."

After attending this session, you will be able to explain and contrast the advantages and challenges of three tools for the diagnosis of cancer—CTCs, cfDNA, and miRNA—and describe the challenges of developing a bench-top analytical technique to create a viable handheld device that can be used at the point of care.