DNAR presents new findings from breast cancer study

The DNA Repair Company (DNAR) study was conducted in collaboration with investigators from the Dana-Farber Cancer Institute and Beth Israel Deaconess Medical Center, both in Boston. The study was conducted using clinical data with so-called ‘triple-negative’ breast cancer, a form of the disease that is not responsive to therapies targeting estrogen receptors, progesterone receptors, or the HER2 receptor.

Clinical biopsies from 143 patients were examined to determine whether the modulation of various DNA repair proteins might have an impact on disease progression. DNA repair pathways correct DNA that has been damaged by many common forms of cancer treatment (chemotherapy and radiation) and play a central role in making tumors resistant to therapy.

With clinical samples from half of the patients, the investigators discovered a statistically significant correlation between the presence of four DNA repair proteins and recurrence-free survival. Investigators were then able to validate the correlation with progression-free survival seen in this cohort by testing the four proteins in the second group of patients.

The marker panel distinguished a high risk group of patients with a medium time to recurrence of 14 months from low risk patients with median time to recurrence of more than 10 years. Even though a number of DNA repair markers produced statistically significant results individually, results observed with the four DNA repair marker panel were superior to those seen with a number of single markers, the company said.

According to the company, these findings are significant, because they suggest that monitoring DNA repair protein profiles in patients with triple-negative breast cancer will contribute important insights as prognostic or predictive tools. In addition, DNA repair pathways may provide a promising target for developing novel therapies for the disease.

Judy Garber, director of the cancer risk and prevention program at Dana-Farber and lead investigator of the study, said: These findings provide intriguing evidence that the activity of certain DNA repair pathways play an important role in determining how patients with triple-negative breast cancer will respond to therapy, and further validation will help focus drug development on approaches most likely to succeed.

The frequently poor prognosis for patients with this form of breast cancer lends increased urgency to understanding the molecular basis of the disease, and its implications for treatment and new drug development.