The Impact of Race and Mammographic Detection in Early Breast Cancer

1
The Impact of Race and Mammographic Detection in
Early Breast Cancer

• Michael A. Nichols, M.D., Ph.D., Loren K. Mell,
  M.D., Dhara MacDermed, M.D., Amber Meriwether,
  Mary Ellyn Witt, R.N., Ralph R. Weichselbaum,
  M.D., Steven J. Chmura, M.D., Ph.D.
• University of Chicago, Department of Radiation
  Cellular Oncology

A
Table 1. Patient and tumor characteristics for
the group and broken down by race.
B
Figure 2. Theoretical model of tumor metastatic
potential as a function of size with regard to
the benefit of mammographic detection. Threshold
represents development of nodal or distant
metastases and may be crossed earlier by black
patients than non-black patients, indicating a
need for earlier mammographic detection for
equivalent outcomes.
Conclusion For patients with stage I-II
invasive breast cancer treated with breast
conservation and radiation therapy, method of
detection is an important prognostic indicator
for non-black but not black patients. Tumor size
has a different prognostic significance dependent
upon race and method of detection. This may
provide a rationale for more frequent screening
mammogram intervals for black women.
Figure 1. Kaplan-Meier curve for disease-free
survival (A) and Cumulative incidence curves for
disease-free survival by race (B). Grays test
was used to compare cumulative incidences. DFS
time was defined as time to first locoregional
failure (LRF), distant failure (DF), or death.
Table 2. (A) Multivariate analysis (MVA) of DFS
stratified by race. (B) Hazard ratio of tumor
size after stratifying by method of detection and
race within each division.