The goal of this observational ambidirectional cohort study is to develop a prediction model to identify the risk of lymphedema after axillary lymph node dissection (ALND) in patients with breast cancer. The main questions it aims to answer are:

• Can clinicopathological factors predict the development of lymphedema?
• Do protein expression profiles and genetic mutations increase susceptibility to lymphedema?

Participants will:

• Undergo clinical evaluation and indocyanine green (ICG) lymphography to diagnose lymphedema.
• Provide lymphatic tissue and blood samples during ALND surgery for immunohistochemical protein analysis and gene mutation assessment.
• Be followed over time to monitor the onset and progression of lymphedema.

Inclusion Criteria:

• Age ≥ 18 years
• Histopathologically confirmed breast cancer
• Undergoing axillary lymph node dissection (ALND)
• Able to undergo indocyanine green (ICG) lymphography examination

Exclusion Criteria:

• Clinical signs of lymphedema prior to surgery, confirmed by clinical assessment and/or ICG lymphography
• History of iodine allergy, asthma, impaired renal function, pregnancy, or breastfeeding
• Incomplete clinical or laboratory data required for analysis

The study population consists of adult patients diagnosed with breast cancer who are undergoing axillary lymph node dissection (ALND) as part of their standard surgical management. Eligible participants are recruited from Dharmais Cancer Hospital and Bogor City Regional General Hospital in Indonesia. Only patients without pre-existing lymphedema and who are able to undergo indocyanine green (ICG) lymphography are enrolled. Both early- and locally advanced breast cancer cases are included, provided clinical data and follow-up assessments can be completed.

The datasets analyzed during the current study are available from the corresponding author upon reasonable request.