Breast cancer develops when abnormal cells in breast tissue grow uncontrollably. It can begin in the milk ducts or lobules and may remain localised or spread to nearby lymph nodes or other parts of the body.

Possible warning signs include a new breast or underarm lump, changes in breast size or shape, skin changes, nipple changes, nipple discharge or other persistent breast abnormalities. Many breast changes are not cancer, but persistent or concerning changes should be evaluated.

Breast cancer evaluation may involve clinical examination, mammography, ultrasound, MRI in selected cases and biopsy. A biopsy is used to establish a definitive diagnosis.

Examples include ductal carcinoma in situ, invasive ductal carcinoma, triple-negative breast cancer and HER2-positive breast cancer. Treatment depends on the specific diagnosis and biological characteristics.

In selected patients, breast-conserving surgery such as lumpectomy may be appropriate. Suitability depends on tumour size, location, disease extent and individual circumstances.

A mastectomy is a surgical procedure in which breast tissue is removed. Different types may be considered depending on the cancer and treatment plan.

Sentinel lymph node biopsy evaluates the first lymph nodes to which breast cancer may spread. It may be used in selected patients to help determine whether cancer has reached the lymphatic system.

Oncoplastic breast surgery combines cancer surgery with plastic-surgery principles to help preserve or restore breast shape when clinically appropriate. The technique is selected according to tumour characteristics and patient factors.

Depending on cancer type and stage, treatment after surgery may include radiation therapy, chemotherapy, hormone therapy or targeted therapy. The need for additional treatment is determined by pathology and clinical assessment.

Reconstructive surgery may be an option for selected patients after mastectomy. Timing and type depend on the cancer treatment plan, individual anatomy, overall health and patient preferences.

Triple-negative breast cancer is a subtype that does not have estrogen or progesterone receptors and does not have high levels of HER2. Treatment is planned according to the specific cancer and individual clinical factors.

Seek medical evaluation for a new breast lump, persistent breast or nipple changes, unusual discharge, skin changes or another unexplained breast abnormality. If cancer is suspected or diagnosed, specialist evaluation can help determine the appropriate diagnostic and treatment pathway.