A well-timed and sensitive liquid biopsy could effectively predict post-surgical recurrence of stage 2 colon cancer, according to a study published in Science Translational Medicine.1

This disease state often presents clinicians with a dilemma, since most cases are resolved with surgery alone, though the disease recurs for some patients who consequently require chemotherapy. Prophylactic chemotherapy, however, would only harm the majority of these patients.

Researchers enrolled 230 patients with resected stage 2 colon cancer, from whom they extracted 1046 plasma samples using a liquid biopsy. Circulating tumor DNA (ctDNA) was detected in 14 patients, 11 of which had recurrent disease within 27 months; recurrence occurred in only 16 of the 164 patients within whom ctDNA was not detected (P < .001).

Patients treated with chemotherapy for whom the disease did not recur had inferior survival if ctDNA was detected after treatment (P = .001).

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The authors concluded that ctDNA is a promising marker for likelihood of cancer recurrence, though it is unclear whether inaccurate predictions are due to a lack of precise correlation between presence of ctDNA and disease recurrence, or whether researchers do not have enough tools and precision to determine, with certainty, whether ctDNA is present.

References

1. Blood test to detect DNA fragments shed from colon cancers predicts disease’s recurrence. EurekAlert! http://www.eurekalert.org/pub_releases/2016-07/jhm-btt070516.php Accessed July 7, 2016.

2. Tie J, Wang Y, Tomasetti C, et al. Circulating tumor DNA analysis detects minimal residual disease and predicts recurrence in patients with stage II colon cancer. Sci Transl Med. 2016;8:346-92.