Image: Depiction of circulating tumor cells detaching from a primary tumor and circulating through the bloodstream (Photo courtesy of CellMax Life).
Colorectal cancer is among the most preventable cancers when detected early. Yet, it is the second leading cancer killer in the USA. Traditional methods like colonoscopies and stool-based tests are invasive or inconvenient and compliance with colorectal cancer screening remains low, leading to most colorectal cancers being detected in late stages, when survival rates are poor.
Circulating tumor cells (CTCs) are cancer cells that detach from a primary tumor and circulate through the bloodstream and are a fundamental mechanism of metastasis. CTCs have long been known to be valuable in cancer detection, but most technologies using CTCs are only able to detect late-stage cancer.
Scientists from Chang Gung Memorial Hospital (Taoyuan City, Taiwan) and their colleagues enrolled 620 people over the age of 20 who were either visiting the hospital for routine colonoscopies or had confirmed colorectal cancer. After a colonoscopy and biopsy, 438 people were found to have either adenomatous polyps (pre-cancerous growths) or early to late-stage colorectal cancer. The remaining study participants had no signs of pre-cancerous growths or colorectal cancer and were the comparison group.
The investigators tested 2mL of peripheral whole blood were from each subject for CTC analysis through a routine blood draw. The blood samples were then processed through the CMx platform (CellMax Life, Sunnyvale, CA, USA). The results of these assays were then compared in a blinded analysis with the colonoscopy results.
The study results showed that the test's sensitivity ranged from 77% for detection of CTCs in pre-cancerous lesions to 87% for stage I-IV cancers. The accuracy of the results, taking into account both sensitivity and specificity, was high and ranged from 84% to 88% for pre-cancerous and cancerous samples. Additionally, the accuracy of this test was superior to that of fecal occult blood testing (FOBT), a guideline-recommended stool test for colorectal cancer screening. This blood test could potentially be offered between USD 100 and USD 150.
Atul Sharan, MBA, MS, co-founder and CEO of CellMax Life, said, “Early detection is perhaps the only real cure for cancer. To be effective, tests for early cancer detection need to be non-invasive, easy, highly affordable and accurate, and our CTC blood test meets all of these requirements. Recent surveys reveal a preference for blood tests over stool-based screening tests in more than 80% of patients who did not undergo invasive colonoscopy screening. This test can be an option for these individuals and boost compliance.” The study was presented on January 20, 2018, at the ASCO Gastrointestinal Cancers Symposium held in San Francisco, CA, USA.
Chang Gung Memorial Hospital