Delaying chemotherapy in breast cancer patients reduces overall survival

Postponing the start of adjuvant chemotherapy for more than 90 days following surgery may significantly increase risk of death for breast cancer patients, particularly those with triple-negative breast cancer (TNBC), according to a new study from The University of Texas MD Anderson Cancer Center. Further, the researchers found that factors such as socio-economic status, insurance coverage and ethnicity were associated with delayed treatment.
Adjuvant chemotherapy, which is given after primary surgery, has been demonstrated to benefit patients by decreasing the risk of recurrence and death, explained Mariana Chavez Mac Gregor, M.D., assistant professor, Health Services Research and Breast Medical Oncology. However, delaying the start of adjuvant chemotherapy may allow small remnants of the tumour to grow or become drug-resistant.
Currently, there are no guidelines recommending the optimal time to initiation of adjuvant chemotherapy. The Centers for Medicare & Medicaid Services (CMS) considers the administration of adjuvant chemotherapy within 120 days of diagnosis for certain patients as a quality metric. Eleven cancer hospitals, including MD Anderson, are now reporting on this metric.
Past studies have suggested that delaying the initiation of therapy could result in adverse patient outcomes, but the optimal timing for starting adjuvant therapy has not been defined. To clarify this time frame relative to modern treatments and identify factors contributing to delayed treatment, the researchers analysed data from the California Cancer Registry.
This population-based study examined data from 24,823 patients with Stage I to III invasive breast cancer diagnosed between January 1, 2005 and December 31, 2010 and treated with adjuvant chemotherapy. This is the largest study investigating the effects of delayed chemotherapy initiation with contemporary treatment regimens.