Comparing the effectiveness of different chemotherapy regimens after surgery in early stage breast cancer

This study compared the effectiveness and safety outcomes of current chemotherapy regimens for treatment in patients with early-stage breast cancer (BC). The data showed that the current treatment regimens have similar effectiveness.

BC is classified into different subtypes depending on the presence or absence of certain receptors (proteins found on the surface of the cancer cells). HER2 negative is a subtype of BC in which cancerous cells do not contain high levels of the HER2 protein. Patients with this subtype of BC commonly receive chemotherapy before or after surgery.

Chemotherapy (CT) after surgery is often used to destroy any remaining cancer cells and to prevent cancer recurrence. This is called adjuvant CT (ACT). A number of clinical trials with ACT have shown significant improvements in survival in patients with early-stage BC. There are several CT regimens recommended for early-stage HER2-negative BC. However, studies comparing the effectiveness of these CT regimens are missing.

This study analyzed 7 trials involving a total of 16,332 patients with HER2-negative early-stage BC. Patients received either DDACT (doxorubicin and cyclophosphamide followed by paclitaxel), TC (docetaxel and cyclophosphamide), TAC (docetaxel, doxorubicin, and cyclophosphamide), ACWKT (doxorubicin and cyclophosphamide for 4 cycles followed by weekly paclitaxel for 12 cycles), or AC (doxorubicin and cyclophosphamide for 4 cycles).

DDACT, TAC, TC, and ACWKT had similar rates of survival free of disease. DDACT had the best disease-free survival rate. All the regimens had better overall survival (OS) rates compared to AC. However, this was not considered statistically significant. 

The most common side effect was low blood cell counts with fever. Patients who received DDACT were the least likely to develop this side effect.  Patients who received TAC were the most likely to develop this side effect compared to the other groups.

This study concluded that the current generation of ACT regimens have similar effectiveness in patients with early-stage BC.

The number of studies included in the analysis was very low. The limited population size and the differences in the population might influence some conclusions.