What does growth fraction indicate?

The growth fraction is a critical concept in oncology that reflects the proportion of actively dividing cells within a tumor relative to those that are in a resting or non-dividing phase. A higher growth fraction indicates that a larger fraction of the tumor cells are proliferating, which is often associated with a more aggressive form of cancer. This is particularly important in the context of chemotherapy, as many chemotherapeutic agents are designed to target dividing cells. Understanding the growth fraction helps in determining the responsiveness of a tumor to various treatment modalities, as tumors with a high growth fraction tend to be more sensitive to chemotherapy compared to those with lower growth fractions. This concept underscores the importance of cell proliferation in cancer dynamics and treatment efficacy.