How BRCA mutations influence prognosis and “pathologically complete responses” when chemotherapy is used

The study looked at the effect of BRCA1/BRCA2 mutations (abnormal genes) on the outcomes of patients treated for breast cancer. The study concluded that the patients who had the BRCA1/2 mutations were more responsive to treatment.

BRCA1 and BRCA2 are genes that stop tumors from being produced in the body. In some women, these genes are abnormal and do not work, therefore these women are more likely to develop breast cancer. Neoadjuvant chemotherapy refers to any treatment before surgery. There has been a large amount of research into whether having these mutations means a patient will respond better to chemotherapy or not.

This study 355 patients with breast cancer, who were treated between 1997 and 2015. 59 of these patients had BRCA1 (43 patients – 12.1%) or BRCA2 (16 patients – 4.5%) mutations.

In the patients who had a BRCA1 and/or BRCA2 mutation, 54.3% achieved a pathologically complete response (no signs of cancer remained after treatment), compared to 22.6% of patients who did not have these mutations. Of the patients who achieved a pathologically complete response, there was no difference in disease free survival (alive without symptoms) between those who had a BRCA1/2 mutation and those who did not. The highest rates of pathologically complete responses were in patients with BRCA1/2 mutations, no hormone receptors, and who had platinum-based chemotherapies.

The study concluded that patients with BRCA1/2 mutations had a better response to chemotherapt tratment for breast cancer.

This was quite a small study sample size with relation to how many patients with mutations were included. It also goes back a long way to 1997. Treatment for breast cancer has improved and updated since the beginning of this study. The rates of pathologically complete response might be a little lower in the study than they are today.

Patients with BRCA1/2 mutations might want to discuss with their oncologist if platinum based therapies would be a good treatment for them.