Abstract

Purpose: Recurrence within the first three years after treatment occurs in ~30% of patients with early stages triple-negative breast cancer (TNBC). However, there is no biomarker to identify them. Radiotherapy (RT) triggers an inflammation in all patients. Some of these inflammatory cytokines promote cancer cell invasion, increase the number of circulating tumor cells and stimulates metastasis development. The purpose of this study is to determine if plasma collected during RT could be used to identify TNBC patients at high risk of recurrence.

Materials and Methods: Plasmas were collected in TNBC patients before RT and after the 4th radiation fraction (plasma during RT). The increase in inflammatory cytokines was analyzed by ELISA type test. The plasmas were incubated with TNBC MDA-MB-231 (human) and D2A1 (mouse) cells in order to determine which plasmas collected during RT increase their invasion capacity in vitro, as well as the formation of metastases in mice.

Results: Our preliminary results obtained from 5 TNBC patients demonstrated that RT increased the plasma level of the cytokines IL-1β, IL-5 and IL-6 only in the patient whose cancer recurred within the first 9 months following treatment. Only plasma from this patient collected during RT increased the invasiveness of TNBC cells in vitro and the formation of metastases in an animal model. The formation of metastasis was completely blocked by adding the cyclooxygenase-2 (COX-2) inhibitor Celecoxib to this plasma collected during RT.

Conclusions: We would like to continue recruiting TNBC patients in order to confirm that plasma collected during RT could identify patients at high risk for recurrence.