Delaying Chemotherapy After Breast Cancer Surgery Can Decrease Survival

Mariana Chavez Mac Gregor, MD, MSC Assistant Professor, Tenure track Department of Health Services Research Division of Cancer Prevention The University of Texas MD Anderson Cancer Center Houston, TX

Dr. Chavez-MacGregor Interview with:
Mariana Chavez Mac Gregor, MD, MSC
Assistant Professor
Breast Medical Oncology Department
Health Services Research Department
The University of Texas MD Anderson Cancer Center

Medical Research: What is the background for this study? What are the main findings?

Dr. Chavez Mac Gregor: Adjuvant chemotherapy has proven to significantly decrease the risk of recurrence among breast cancer patients, however the optimal time to start adjuvant chemotherpay remains unknown. There are biological resasons to believe that a delay in the initiation of systemic therapy can be associated with adverse outcomes. In this large study we evaluated the impact of a delay in the initiation of time to chemotherapy (TTC).  We analyzed data from 24,843 patients with invasive breast cancer (stages I to III) from the California Cancer Registry and observed that compared with patients who received chemotherapy within 31 days of surgery,  no adverse outcomes were associated with time to chemotherapy of 31 to 90 days of surgery. However, there was  a 34 % increase in the risk of death and a 27% increase in the risk of breast cancer specific death  among patients who started  chemotherapy 91 or more days after surgery. In a stratified analysis according to breast cancer subtype, patients with triple-negative breast cancer, a TTC greater than 91 days  was  significantly  associated with worse overall and breast cancer-specific survival.

In addition we evaluated factors associated with delays in  time to chemotherapy (defined as > or = 91 days) and observed that many of the factors are sociodemographic in nature including low socioeconomic status, non-private insurance, and being Hispanic or African American.

Medical Research: What should clinicians and patients take away from your report?

Dr. Chavez Mac Gregor: Given the results of our analysis, we would suggest that all breast cancer patients that are candidates for adjuvant chemotherapy should receive this treatment within 91 days of surgery. Administration of chemotherapy within this frame is feasible in clinical practice under most clinical scenarios, and as medical oncologists, we should make every effort not to delay the initiation of adjuvant chemotherapy. Furthermore, since some of the determinants of the delays in time to chemotherapy  are sociodemographic in nature; better understanding and removing barriers to access of care in vulnerable populations should be a priority.

Medical Research: What recommendations do you have for future research as a result of this study?

Dr. Chavez Mac Gregor: We are currently evaluating at the impact of delays in surgery among patients with locally advanced breast cancer treated with neoadjuvant chemotherapy and plan also to look at delays in initiation of chemotherapy as initial treatment strategy in patients with locally advanced breast cancer. We belive we need to learn how to better administer and deliver our current therapies. Also understanding barriers to optimal care, will help us identify vuberable populations were simple interventions can lead to improvement of outcomes.


2015 SABCS abstract:

[P1-12-07] Delayed initiation of adjuvant chemotherapy among breast cancer patients: A population-based study
 Authors: Chavez-MacGregor M, Clark CA, Lichetensztajn DY, Giordano SH

Date/Time: Wednesday, December 9, 2015 – 5:00 PM

Session Info: Poster Session 1: Treatment: Adjuvant Chemotherapy (5:00 PM-7:00 PM

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Mariana Chavez Mac Gregor, MD, MSC (2015). Delaying Chemotherapy After Breast Cancer Surgery Can Decrease Survival 

Last Updated on December 14, 2015 by Marie Benz MD FAAD