Study supports DNA mismatch repair test for bowel cancer

February 09, 2016

"There is still uncertainty, for example, whether the modest benefits of chemotherapy in locally advanced colorectal cancer where the tumor has not spread to the lymph nodes, (stage II disease), are sufficient to justify the toxicity, cost and inconvenience of the treatment. In this situation the selection of patients who are most likely to benefit from therapy remains problematic.

"Currently we assess the probability that a patient's tumor will recur through thorough and detailed, but often subjective, pathological assessment. The supplementation of this approach with objective, quality assured biomarkers in patients with bowel cancer could accurately predict the likelihood of recurrence and allow us to aggressively treat only those patients whose tumors are much more likely to return, sparing a significant proportion of bowel cancer patients needless chemotherapy.

"Many biomarkers have been suggested but none have so far been sufficiently validated for routine clinical application mainly because previous studies have been too small to be convincing and lacked a randomised control group.

"This new data provides unequivocal support for calls to routinely test for defective DNA damage repair in bowel cancer patients, a testing strategy that is an inexpensive and technically simple procedure. The results of this study also support further evaluation of BRAF and KRAS gene mutations to predict tumor recurrence," he said.

Source: University of Leeds