Factors contributing to disparities in early breast cancer treatment

Specific Aims: This dissertation was conducted to examine the following specific aims among early breast cancer patients: 1) Racial differences in the use of pre-operative magnetic resonance imaging (MRI) and the role of pre-operative MRI on rates of re-operation and contralateral prophylactic mastectomy (CPM), and time to surgery; 2) Racial differences in elapsed time and sessions received during radiation therapy; and 3) Racial differences in chemotherapy dose modifications and role of neutropenia in this association. Design, setting and subjects: Subjects were selected from the Breast Cancer Treatment Disparity Study which is an ongoing cohort study of African American (AA) and white subjects residing in eastern New Jersey who were newly diagnosed with early breast cancer between 2005 and 2010. Data were collected through a detailed review of medical records obtained from multiple health care providers of these participants. Results: A significantly higher use of pre-operative MRI among whites versus AAs (58.3% vs. 39.7%, p49 days elapsed time= 36%, and mean sessions= 33, for both racial groups). In the third study, a significantly lower relative dose intensity (RDI) was delivered to AA subjects than white subjects (94.4% versus 100.0%, p= 0.005) during chemotherapy and the risk of >15% reduction in RDI was more than double (RR= 2.62; 95% CI: 1.40, 4.89) in AA women as compared to white women. White blood cell counts at initiation of chemotherapy and in subsequent cycles were similar between the races and were unable to account for differences in dose intensity between the two groups. Conclusion: The rapid rise in use of pre-operative MRI is a concern as no benefit of its use was observed in this study. We also conclude that once treatment is initiated AA women and white women were very similar in receipt of care delivered during radiation. However, this did not hold true for chemotherapy. AA women in comparison to white women were at more than two-fold risk of experiencing dose modifications during chemotherapy that was not explained by differences in their blood counts.Ph. D.Includes bibliographical referencesIncludes vitaby Sheenu Chandwan