BRCA1 mutations account for less than 5% of breast cancers, but up to 1% of the Jewish population has such a mutation. Up to 80% of BRCA1 carriers can go on to devlop breast cancer.

The BRCA research group in Toronto looked at which chemotherapy works best in patients with a BRCA1 mutation and breast cancer. The paper is published in this week's JCO.

They used the neoadjuvant setting. This is not all that common in clinical practice, but a good format for checking the activity of chemotherapy in breast cancer. The idea is to give chemo prior to surgery, then see how many patients have complete resolution of their disease by the time they have surgery. This is handier than a survival endpoint, where you might have to wait for many years for sufficient numbers of patients to die to complete your clinical trial. Researchers love the neoadjuvant setting not because it's all that applicable to the usual treatment of breast cancer patients, but because they get their results more quickly. Also, you get pathologic confirmation of the result of the treatment, and you're not subjecting patients to extra procedures.

So cisplatin showed a markedly better success rate than other conventional types of chemo for women with a BRCA1 mutation and tumor. It's a small finding, of some interest to breast cancer patients and oncologists.

This is a major finding for individualizing treatment: we try to figure out which treatments work best for which particular patient. Progress is slow--this whole study only applies to a few thousand women each year, though it's a good start. We think maybe other breast cancers are driven by similar losses in DNA mismatch repair gene function as BRCA1-mutated tumors are, and if that's the case, perhaps we can expand these findings to a larger group of people.