The road towards less axillary treatment in early breast cancer patients and faster implementation of study results

Breast cancer is the most common form of cancer in women in the Netherlands. Currently, 1 in 7 women will develop breast cancer during her lifetime. Treatment for breast cancer consists of a combination of surgery, systemic therapy and radiotherapy. These treatments have increased the 5-year survival rate in recent years. This dissertation focuses on the path to less axillary treatment in patients with early-stage breast cancer, with the goal of selecting patients in whom axillary treatment can be reduced, thereby reducing axillary morbidity and improving these patients' quality of life. Ongoing studies will answer these questions in the future. This dissertation examined whether the follow-up period of these clinical trials could be optimized. The absolute yield to detect recurrence (local or regional) after 3 years is low, suggesting that follow-up longer than 3 years is of limited value in both clinical and research settings. It was also shown that staging systems, combining traditional staging with tumor biology, can determine more patient-tailored prognosis.