The purpose of this epidemiologic study is to establish a population-based cohort of women with advanced stage breast cancer which can be used to quantify the frequency and timing of brain metastases, and other distant metastases, in this patient population.

A retrospective cohort study will be conducted in the Henry Ford Health System (HFHS). Using medical record review, we will identify all women diagnosed with advanced stage (stage III and IV) breast cancer between January 1, 1995- December 31, 2007. For each case included in the study, we will obtain data on demographics, tumor information, treatment related medical encounters and procedures, and occurrence and timing of brain and/or other distant metastases. The main outcome for this study is the development of distant metastases. Each patient in the cohort will be classified as to the occurrence and date of distant metastases. Metastases will be classified as Brain, Distant lymph node, Lung/pleural effusion, Liver, Bone, Other visceral, Other non-visceral.

Other secondary outcomes to be explored include:

• Survival after advanced breast cancer-time in months from the date of advanced stage breast cancer diagnosis until death or end of study period
• Time to brain metastases-time in month from the date of advanced stage breast cancer diagnosis until brain metastases diagnosis
• Survival after brain metastases-time in months from the date of diagnosis of brain metastases until death or end of study period

Inclusion Criteria:

• Initially diagnosed with American Joint Commission on Cancer (AJCC) stage III or stage IV breast cancer between January 1, 1995 through December 31, 2007 -OR- diagnosed with AJCC stage I or II breast cancer and progressed to stage III or IV disease between January 1, 1995 through December 31, 2007;
• At least one year of follow-up after initial diagnosis (among patients who did not die before one year of follow-up); and
• Age 30 years or older at diagnosis.

Exclusion Criteria:

• Does not have at least one year of follow-up after initial diagnosis (among patients who did not die before one year of follow-up); and
• Age less than 30 years or older at diagnosis.

This study aims to retrospectively collect data on nearly 4,000 advanced breast cancer cases treated within the Henry Ford Health System