CNS metastases in women with secondary breast cancer

Background

Metastatic breast cancer, also known as secondary breast cancer or advanced breast cancer is defined as invasive breast cancer that has spread from the breast to other parts of the body.

Treatment for women with metastatic breast cancer includes the use of supportive drug treatments to reduce disease-related symptoms and slow the progression of disease, thereby extending and enhancing the woman’s quality of life.

Breast cancer is a common cancer associated with central nervous system (CNS) metastases. Approximately 10-15% of women living with metastatic breast cancer will be diagnosed with CNS metastases. Improvements in the systemic treatment of breast cancer have resulted in an increased incidence of CNS metastases as patients survive long enough to experience progression in the brain. Advances in technology and increasing availability of imaging modalities such as MRI, allow detection of small metastases at follow-up screening examinations. CNS metastases are less common than bone, liver or lung metastases. In most cases, involvement of lungs, liver or bone precedes diagnosis of CNS metastases.

Women with HER2-positive or triple negative breast cancer have been reported to have an increased risk of developing CNS metastases. Other risk factors associated with an increased likelihood of developing CNS metastases include young age (<40 years), pulmonary metastases, BRCA1 mutation carriers and ER-negative tumours.

A systematic review on the management of CNS metastases in women with metastatic breast cancer was undertaken to support the development of this clinical practice guideline. For details on the literature search including research questions, refer to Evidence from trial or study results in the guidelines.