Date of Award

January 2011

Document Type

Open Access Thesis

Degree Name

Medical Doctor (MD)



First Advisor

Meena Moran

Subject Area(s)



Purpose: To compare mammographically occult (MamOcc) and mammographically positive (MamPos) early-stage breast cancer patients treated with breast-conservation therapy (BCT), to analyze differences between the two cohorts.

Methods: The 2 cohorts were comprised of 214 MamOcc and 2168 MamPos patients treated with BCT. Chart reviews were conducted to assess mammogram reports and method of detection. All clinical-pathologic and outcome parameters were analyzed to detect differences between the two cohorts.

Results: Median follow-up was 7 years. There were no differences in final margins, T stage, nodal status, estrogen/progesterone receptor status, or "triple-negative" status. Significant differences included age at diagnosis (p < 0.0001), more positive family history (p = 0.0033), less HER-2+ disease (p = 0.0294), and 1° histology (p < 0.0001). At 10 years, the differences in overall survival, cause-specific survival, and distant relapse between the two groups did not differ significantly. The MamOcc cohort had more breast relapses (15% vs. 8%; p = 0.0357), but on multivariate analysis this difference was not significant (hazard ratio 1.0, 95% confidence interval 0.993-1.007, p = 0.9296). Breast relapses were more commonly not picked up on mammography in the MamOcc cohort (32% 12% p = 0.0136).

Conclusions: Our study suggests that there are clinical-pathologic variations for the MamOcc cohort vs. MamPos patients that may potentially affect management, but that breast relapse rates after BCT are ultimately not significantly different for these 2 cohorts. Breast recurrences were more often mammographically occult in the MamOcc cohort; consideration should be given to closer follow-up and alternative imaging strategies (ultrasound, breast MRI) for routine post-treatment examination. To our knowledge, this represents the largest series addressing the prognostic significance of MamOcc cancers treated with BCT.


This is an Open Access Thesis.

Open Access

This Article is Open Access