The Metastatic Receptor Status Impact on First-Line Treatment Plans and Outcomes for Recurrent Metastatic Breast Cancer

Background: For more than two decades, breast cancer researchers have studied the benefits, risks and clinical importance of testing the receptor status of metastatic tumors. While there is a growing consensus that the status should be re-tested and under what circumstances that re-testing should occur, there is little to no evidence that utilizing test results for metastatic tumor receptor status improves the clinical outcomes of patients. In fact, there is evidence that changes to treatment plans based on this re-testing can be harmful to patient outcomes.

Objective: This dissertation evaluates the current state of evidence related to altering patient treatment plans based on the re-test results of metastatic tumors, offers an update to existing national and international standards and executes a retrospective observational study to provide data that supports better informed decisions on first-line metastatic treatment plans where retesting of tumors is an option.

Methods: A thorough literature review was performed on the topic. Afterwards, a retrospective observational study was performed at the University of Tennessee Cancer Institute.

Conclusions: The research outcomes documented in this dissertation demonstrate that basing first-line treatment plans for metastatic breast cancer patients on the receptor status of the primary tumor instead of the metastatic tumor receptor status extends the life expectancy of patients. A standard of care is proposed that impacts national and international guidelines and reflects the risks associated with changing the first-line treatment plans of metastatic breast cancer patients based on the receptor status of metastatic tumors.