133 Improved Survival of Bulgarian Breast Cancer Patients, Diagnosed in 2006-2009 Compared to Patients From an Earlier Period

Results: Percentage mammographic density (PD) was positively associated with tumor size (p = 0.004) and grade (p = 0.033), but the relationship with grade was attenuated after adjustment for, among other variables, mode of detection (p = 0.069). Furthermore, PD was associated with both breast and locoregional recurrence even after adjustment for treatment; women with PD 25% had a hazards ratio (HR) of 1.96 for breast recurrence and a HR of 1.78 for locoregional recurrence compared to women with PD <25% (p = 0.032 and p = 0.017, respectively). No other associations between PD and the tumor characteristics studied (hormone receptor status, lymph node metastasis, proliferation rate, and histopathological classification) were observed, nor was PD associated with distant metastasis and survival. Conclusion: Density may be viewed as fertile soil; increasing both risk of primary breast cancer, independent of subtype, and risk of recurrence. Thus, density should not only be taken into consideration in the screening setting, but also when making decisions on adjuvant therapy and follow-up regimes.