Olaparib for treating breast cancer that has spread

This study determined whether treating breast cancer that has spread (metastatic) with olaparib (Lynparza) resulted in better outcomes and fewer side effects compared to chemotherapy. The study found that treatment with olaparib led to similar survival outcomes compared to chemotherapy. 

There are many different types of breast cancer. A common type of breast cancer is called BRCA breast cancer. This is cancer that has a mutation in the BRCA gene. This type of cancer can be treated in a different way compared to cancer that does not have the mutation.

There are several different treatments for breast cancer. Cancer that has spread (metastatic) is often harder to treat. Sometimes treatment with one drug does not work, so many different drugs need to be tried. Olaparib is a new anti-cancer drug. It is unclear whether olaparib is safer and more effective than chemotherapy for patients with metastatic breast cancer.

This study had 302 patients. All patients had metastatic breast cancer with mutations in the BRCA gene. Patients previously received 0, 1, or 2 treatments. 205 patients were treated with olaparib. 97 were treated with chemotherapy. Patients were followed-up for an average of 26 months. 

At the end of follow-up, the patients who were treated with olaparib survived on average for 19.3 months. The patients who were treated with chemotherapy survived for 17.1 months. In the olaparib group, patients who did not receive chemotherapy before survived longer compared to patients who previously received chemotherapy (22.6 vs. 14.7 months).

In the olaparib group, most side effects were mild. 38.0% of patients had severe side effects compared to 49.5% of patients treated with chemotherapy. The most common ones were low red blood cell count (16.1% vs. 4.4%) and low white blood cell count (9.3% vs. 26.4%).

This study concluded that there was no significant difference in survival outcomes between patients with breast cancer treated with olaparib versus those treated with chemotherapy. The authors suggest that olaparib may improve the outcomes of patients who have not previously received chemotherapy for cancer that has spread.

This is a small study. Larger studies are needed to confirm these results.