To evaluate the influence of mammographic breast density at diagnosis on the risk of cancer recurrence and survival outcome in patients with invasive breast cancer after surgery

Inclusion Criteria:

• Women diagnosed with invasive breast cancer between 2004 and 2009 who had undergone surgery and had the mammographic breast density ascertained before, or at, diagnosis.

Exclusion Criteria:

• Women diagnosed with invasive breast cancer between 2004 and 2009 who had not undergone surgery or who had no mammographic breast density ascertained before, or at, diagnosis.

Women diagnosed with invasive breast cancer who had undergone surgery between 2004 and 2009