Comparing platinum-based chemotherapy and immunotherapy for the treatment of patients with early-stage triple negative breast cancer.

This study compared the effectiveness and safety outcomes of platinum-based chemotherapy and immune checkpoint inhibitors (ICIs) for the treatment of patients with early-stage triple-negative breast cancer (TNBC). The data showed that ICI plus chemotherapy was associated with good outcomes with reduced side effects compared with platinum-based chemotherapy in these patients.

TNBC is a subtype of BC that tests negative for female hormone receptors (estrogen and/or progesterone) and the HER2 protein. TNBC accounts for 10-15% of all BCs. It is associated with a poorer outcome compared to other subtypes of BC. Treatments for TNBC usually involve a combination of surgery, chemotherapy, and radiotherapy.

Platinum-based agents such as carboplatin (Paraplatin) are chemotherapy drugs that damage the DNA in cancer cells, causing the cells to die. Immune checkpoint inhibitors (ICIs) are a type of immunotherapy used to treat a wide variety of cancers. Tumor cells try to avoid death by switching off the immune system.

ICIs such as pembrolizumab (Keytruda) work by blocking the off switch of the immune system. Pembrolizumab has been approved for use as a first-line treatment in metastatic TNBC. However, there are very few studies comparing the effectiveness and safety of platinum-based chemotherapy and ICIs for the treatment of patients with early-stage TNBC.

This study analyzed 7 studies involving a total of 1647 patients with early-stage TNBC. Patients were divided into 2 groups based on the treatment they received before surgery. Group 1 included 845 patients who received standard chemotherapy (anthracyclines or taxane-based). Group 2 included 802 patients who received either ICIs plus platinum-based chemotherapy or platinum-based chemotherapy alone.

Patients who received standard chemotherapy had similar outcomes as those who received platinum-based chemotherapy alone. However, adding ICIs to platinum-based chemotherapy was associated with a 2.64 times higher chance of achieving pathological complete response (pCR; the absence of any cancer cells after surgery) compared to standard chemotherapy. 

ICIs plus chemotherapy was 1.78 times more likely to achieve pCR than those who received platinum-based chemotherapy alone. Patients who received ICIs plus chemotherapy had a 54% reduced risk of stopping treatment due to side effects than those who received platinum-based chemotherapy.

This study concluded that ICIs plus chemotherapy significantly increased pCR rate and decreased side effects compared with platinum-based chemotherapy in patients with early-stage TNBC.

This study looked back in time at medical records. The number of studies analyzed was very small. This study did not directly compare ICIs versus platinum-based chemotherapy. Further studies with direct comparisons of these two treatments are required.