Researchers studied 664 patients who had early stage breast cancer. They compared two main treatment groups. One group received a mix of three drugs called TAC. The other group got a faster schedule of two drugs called ddAC. The goal was to see which plan kept the cancer from returning or spreading better.
Scientists looked closely at specific parts of the cancer cells to find patterns. They found that some tumors responded very well to the three-drug plan. In these cases, the chance of the cancer returning was much lower. Other tumors did better with the two-drug plan, especially when cell markers were checked first.
The team noted that knowing more about the cancer cells helps make smarter choices. However, they said they need to study more people to be sure. This research helps doctors understand how to match the right medicine to the right patient.