Kits for Cancer

Featured Article

To aim cancer research and treatments at specific molecular targets, scientists and clinicians need sophisticated diagnostic tests.

Based on statistics from the American Cancer Society, more than one person in the United States dies every minute from cancer. So, in the time that it takes to read this article, more than five Americans will die from this family of diseases. According to the U.S. Centers for Disease Control and Prevention, cancer is the second leading killer in America, despite advances in diagnosis and treatment. To improve our knowledge of how specific cancers emerge and progress, diagnose patients more accurately and precisely, and develop more targeted treatments, scientists and clinicians need accurate and easy-to-use diagnostic tests.

The market for molecular diagnostic kits for cancer offers many options. Moreover, this market is expected to grow dramatically. Molecular diagnostic kits for blood cancer, for example, are forecast to surge from $335.9 million in 2016 to $6,980 million in 2020¹—an increase of more than 20 times in a decade.

As a quick public service announcement, profitable markets can produce good and bad results. For example, a variety of at-home kits exist for cancer detection. Maybe these kits test for what they indicate, and maybe they don’t. Even if they do, it still takes an expert to analyze the results of a test. No matter who makes a kit, the manufacturer should readily provide data that indicate a kit’s accuracy. So, scientists, clinicians, and patients must require companies to thoroughly test and document a test’s capabilities and run ongoing quality to control to maintain a kit’s usefulness.

Now, let’s take a look at a few of the options.

Kinds of kits

Molecular diagnostic kits for cancer rely on various forms of technology, such as enzyme-linked immunosorbent assays (ELISAs). For example, DRG International (Springfield, NJ) developed an ELISA-based kit that analyzes a tumor marker called CA72-4, which is a cancer antigen. This kit is certified for research-use-only (RUO) in the United States and is CE marked for use in other countries. Based on one study of 96 patients, the company concluded: “CA72-4 may have a potential role as an adjunct to conventional biomarkers in disease monitoring of pancreatic, ovarian, and colorectal carcinomas.”

Cancer cells (purple) can spread through blood, and some diagnostics can detect these circulating tumor cells. (Image courtesy of Darryl Leja, National Human Genome Research Institute, U.S. National Institutes of Health.)

Many tests also analyze gene mutations that could contribute to cancer. For instance, IBL-America (Minneapolis, MN) offers an ELISA-based kit that detects P53, a tumor-suppressor gene, in serum, plasma, or cell-culture fluids. This product is RUO and designed to detect human P53—down to less than 10 picograms per milliliter.

Instead of analyzing samples gene by gene, some tests look for a list of changes. Scientists at Thermo Fisher Scientific (Waltham, MA) use next-generation sequencing (NGS) on the company’s Ion Torrent and Oncomine NGS technology. In the United States, the Oncomine Dx Target Test is approved by the U.S. Food and Drug Administration (FDA) to detect mutations related to non-small lung carcinoma (NSCLC). With one sample and four days, this test returns information on 23 genes and three biomarkers. The company describes this test as “a companion diagnostic device to aid in selecting NSCLC patients for treatment with targeted therapies,” including gefitinib, crizotinib, and others.

Super specific

Some of the cancer-related kits mirror the increasing precision of the field in general. That is, instead of using broad-based forms of chemotherapy that battle a range of cancers with relatively crude methods—essentially attacking any fast-dividing cells—newer treatments tend to work for particular kinds of cancers and go after specific molecular targets.

In Portland, Oregon, for instance, MolecularMD offers the MRDx BCR-ABL Test for patients with chronic myeloid leukemia (CML). But that’s just the start of this test’s focus, because is it intended for patients treated with Tasigna, but who may be able to go off treatment. Then, these patients would be monitored for treatment-free remission. That is, instead of continuing treatment for CML, they would be carefully tracked for any recurring cancer. Doing that requires extremely precise measurements of cancer markers—in this case proteins from a fusion gene called BCR-ABL. This mutation, known as the Philadelphia chromosome, appears in most people who have CML, as well as those with acute lymphoblastic leukemia and acute myelogenous leukemia.

Various diagnostics study chromosomal changes in cancer, such as these chromosomes from a glioblastoma. (Image courtesy of Thomas Ried, NCI Center for Cancer Research, National Cancer Institute, U.S. National Institutes of Health.)

In describing people who could use this test, the company notes: “These patients no longer take daily oral therapy but continue to be actively managed through frequently scheduled monitoring of molecular response with the MRDx BCR-ABL Test.”

One key benefit of a test like this one is that patients don’t need to take medication unnecessarily. In addition, for patients who go off treatment, this test provides them with peace of mind that the cancer remains in remission. If that cancer does come back, the patient knows as soon as possible and can resume treatment. In addition to FDA approval, the MRDx BCR-ABL Test has a CE mark.

Following the flow

Scientists also keep developing advances that can spawn new diagnostic kits for cancer. For example, Lim Chwee Teck of the National University of Singapore and his colleagues developed a microfluidic device—literally, consisting of microscopic channels in which fluids flow—that can measure circulating tumor cells (CTCs).² CTCs break off of tumors and circulate in the blood. Collecting and measuring CTCs can be used in a liquid biopsy, in which blood is analyzed for any signs of a tumor-based cancer.

The authors describe this technology as “a simple but unique microfluidics-based culture approach that requires minimal preprocessing (∼30 min) and does not require prior enrichment of CTCs or depend on the use of growth factor supplements.” Then, drugs can be tested against a patient’s CTCs to develop a plan of personalized treatment. “Owing to the cost-effectiveness and less-invasive nature of this procedure, routine monitoring of disease progression can be achieved,” the authors note. Plus, it’s fast, turning around a result in just 48 hours. Technology like this can be used in drug discovery or—perhaps, one day—in an oncologist’s office.

In fact, many of the technologies mentioned here could be used in research or applied medicine, where approved. More important, this field is just getting started. As this sector of cancer research and treatment expands, so will the kinds of technology used and the expanse of the testing possible.

References

1. Seo, J.H.; Lee, J.W. et al. The market trend analysis and prospects of cancer molecular diagnostics kits. Biomater Res. 2018, 22, 2; doi: 10.1186/s40824-017-0111-9.
2. Khoo, B.L.; Grenci, G. et al. Expansion of patient-derived circulating tumor cells from liquid biopsies using a CTC microfluidic culture device. Nature Protocols 2018, 13, 34– 58.

Mike May is a freelance writer and editor living in Texas. He can be reached at [email protected]