July 9 (UPI) -- A new blood test may help people diagnosed with breast cancer predict if they will relapse later in life, a new study says.
Researchers developed a method to show certain T cell expressions that indicate breast cancer relapse three to five years later, according to new findings published Monday in Nature Immunology.
"This is the first success linking a solid tumor with blood biomarkers -- an indicator of whether a patient will remain in remission," said Peter P. Lee, Immuno-Oncology department chair at City of Hope and study corresponding author, in a news release. "When patients are first diagnosed with cancer, it is important to identify those at higher risk for relapse for more aggressive treatments and monitoring. Staging and new tests based on genomics analysis of the tumor are currently available for risk stratification. However, a predictive blood test would be even more attractive but is not yet available. We are trying to change the status quo."
The researchers examined data for 40 breast cancer patients who were followed for a median of four years. To create this new tool, they examined those patients' peripheral blood to look for signaling responses to various pro- and anti-inflammatory cytokines within multiple immune cell types.
They noticed the regulatory T cells in some patients contained modified to two pro- and two anti-inflammatory cytokines.
Total immune system health is based largely on the balance of cytokine signaling responses in peripheral blood immune cells, the researchers say. For cancer patients, the responses are normally reduced, indicating the area within the systemic immune where cancer growth is likely. When a patient has these patterns of signaling at diagnosis, it can show the chances of future relapse.
The researchers applied their data to design a cytokine signaling index, which acts as a standard for the likelihood of cancer relapse. A doctor can run a patient's blood through this tool to predict their risk and timeline for relapse, according to the researchers.
"Knowing the chance of cancer relapse will inform doctors how aggressive a particular patient's cancer treatment should be," Lee said. "The CSI is an overall reflection of a patient's immune system at diagnosis, which we now know is a major determinant of future relapse."