Researchers are steps closer to better predicting the return of colon cancer. The prediction can be made using a blood test that detects bits of DNA shed from colon cancer. Known as liquid biopsy, the technique can predict with imperfect accuracy the return of colon cancer in patients with early forms of the disease.
Coauthor Nickolas Papadopoulos said, “Although this and other DNA-based blood tests are not perfect, this study shows that when we find tumor DNA circulating in the blood of cancer patients, recurrence is very likely.”
Because in stage 2 colon cancer hasn’t spread to other organs yet, determining the effectiveness of chemotherapy after surgery is difficult.
“Some of these [stage 2] cancers will recur, and we need to improve our diagnostic approaches to detect recurrence earlier than it can be found with current, conventional methods,” added Dr. Bert Vogelstein, co-director of the Ludwig Center at the Johns Hopkins Kimmel Cancer Center.
The researchers followed 230 patients with stage 2 colon cancer. Over 1,000 blood samples were collected prior and after surgery, along with tumor tissue samples for genetic analysis.
Cancer-related mutations in the blood samples were monitored using DNA tests. The patients underwent CT scans six months after surgery to see if the cancer had returned.
Among the 230 patients, 20 had telltale cancer-linked DNA fragments in their blood.
Of those 20 patients, six underwent chemotherapy and three of those six experienced cancer recurrence. Among the remaining 14 who did not undergo additional chemotherapy, 11 developed recurrent cancer.
Unfortunately, the test is not perfect, as cancer returned in 14 other patients who did not have any indication of recurrence in their blood.
Dr. David Bernstein, chief of hepatology at Northwell Health in Manhasset, concluded, “This study is an important first step, but it remains a first step of a likely long road ahead to perfect this technology to the point where it can be clinically useful and affordable to our health system.”
Also, read Bel Marra Health’s article: New colon cancer genes discovered: Study.