Targeted axillary surgery followed by radiation therapy or complete removal of lymph nodes in breast cancer

Breast cancer (mammary carcinoma) is a malignant disease of the breast tissue and the most common cancer in women, though it can also affect men. If the disease has spread to the lymph nodes in the armpit, these have traditionally been completely removed surgically. However, this procedure—known as axillary dissection—can cause significant and sometimes permanent side effects, including swelling of the arm (lymphedema), chronic pain, sensory disturbances, and limited range of motion. A newer, less invasive procedure is known as tailored axillary surgery (TAS), in which only the cancer-affected and previously marked lymph nodes, as well as the sentinel lymph node, are selectively removed, while the remaining lymph nodes are preserved. This spares many patients the long-term complications associated with radical axillary lymph node dissection. Subsequently, a second surgery may be indicated, in which the remaining lymph nodes in the armpit are surgically removed (axillary lymph node dissection, ALND), or radiation therapy is administered to the axillary lymph nodes (axillary radiation therapy, ART).

The aim of this study is to investigate whether the combination of TAS and subsequent radiation therapy to the axillary lymph nodes is superior to radical axillary dissection. In particular, the study will examine arm-related quality of life and the occurrence of lymphedema within two years after completion of treatment. All patients will first undergo TAS, in which abnormal and marked lymph nodes in the axilla are selectively removed. Subsequently, patients will be randomly assigned to one of two study arms. In the control arm, in addition to TAS, a complete removal of all remaining axillary lymph nodes is performed, followed by radiation therapy to the lymphatic drainage area of the breast, excluding the operated axilla. In the study arm, no further surgery is performed; instead, the entire axillary region, including the lymphatic drainage area, is irradiated. The study is open-label, meaning that both the patients and the study physicians know which treatment the patients have been assigned to. The follow-up period is approximately 2 years.

Eligible participants include women and men aged 18 and older with histologically confirmed stage 2 or 3 breast cancer in which axillary lymph node involvement has been detected. Patients must be scheduled for initial surgical treatment.