Undue delays between phases of breast cancer treatment have been linked to less favorable outcomes. Women with aggressive types of breast cancer such as triple negative (ER-/PR-/HER2-) or inflammatory breast cancer (IBC) appear to be the most vulnerable to treatment delays. Now a new study has quantified the potential impact of a delay in chemotherapy after surgery for triple negative disease.
Surgery can increase metastatic potential
A breast tumor may have been growing for a number of years before diagnosis without having undergone the transition to metastatic growth. However, surgery is associated with an increase in the metastatic potential of any cancer cells remaining after surgery. For example, surgery appears to promote the proliferation and motility (ability to move) of tumor cells left behind, thereby allowing their escape into circulation. In fact, surgery has been shown to induce harmful modifications in the expression of genes implicated in metastasis. Therefore, it is important that adjuvant chemotherapy occur in a timely manner after surgery.
Latest research outlines impact of delays
The German retrospective study referenced above was designed to investigate the association between time to initiation of adjuvant chemotherapy and survival in triple negative breast cancer patients. Note that adjuvant chemotherapy takes place after surgery whereas neoadjuvant chemotherapy is designed to shrink a tumor before surgery.
To conduct the study, the authors used data concerning 245 triple negative breast cancer patients who were diagnosed between 2010 and 2018 and registered in Tumor Centre Regensburg. Time to initiation of adjuvant chemotherapy was defined as the number of days between surgery and first dose of adjuvant chemotherapy. Median time to initiation was 29 days.
Patients receiving systemic therapy within 22 to 28 days after surgery were found to have median overall survival of 10.2 years, compared to 8.3 years for 29 to 35 days time to initiation, 7.8 years for 36 to 42 days, and 6.9 years for over six weeks.
The authors conclude that delays in adjuvant systemic therapy can influence overall survival in triple negative breast cancer patients. Efforts should be made to ensure timely initiation of systemic therapy since it would optimize patient outcomes, according to the authors.
Please see our article on triple negative prognosis and the treatment delay tag for more information.