Is chemotherapy beneficial for the treatment of patients with T1bN0M0 triple-negative breast cancer?

This study evaluated the benefits of chemotherapy after surgery in patients with T1bN0M0 triple-negative breast cancer (TNBC). The data showed that chemotherapy after surgery resulted in similar outcomes as patients who did not undergo chemotherapy.

Triple-negative breast cancer (TNBC) is a subtype of breast cancer (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 disease outcome compared to other subtypes of BC. Treatments for TNBC usually involve a combination of surgery, chemotherapy, and radiotherapy.

Patients with T1bN0M0 TNBC have a tumor whose size is between 5 to 10mm. There is no evidence of cancer in the lymph nodes and no distant metastases (cancer spread away from the original tumor). Chemotherapy after surgery is often used to prevent cancer recurrence. However, whether chemotherapy after surgery brings additional for patients with T1bN0M0 TNBC is still unknown.

This study analyzed data from 1849 women with T1bN0M0 TNBC. All patients had their tumors surgically removed and were put into 2 groups. Group 1 included 1155 women who received chemotherapy. Group 2 included 694 women who did not receive chemotherapy. The average follow-up time was 44 months.

The 5-year estimated overall survival rate was 95.4% for patients in group 1 compared with 90.2% for those in group 2. The 5-year breast cancer-specific survival (BCSS; the percentage of patients who did not die of breast cancer) rate was similar between group 1 (96.1%) and group 2 (96%).

Patients who did not receive chemotherapy showed a higher mortality rate from other causes than BC (5.4%) compared with those who received chemotherapy (0.7%).

This study concluded that patients with T1bN0M0 TNBC who had chemotherapy after surgery had similar breast cancer-specific survival as those who did not receive chemotherapy. The authors suggested that a reduction of the intensity of treatment in certain patients might be a good option.

This study was based on medical records. Information such as the type and duration of chemotherapy was missing. This might affect the results.