Effect of Post IORT Wound Fluid Secretion (PIWFS) on the Behavior of Breast Cancer Cells: Stimulator or Inhibitor; Report of an Experimental Study on Breast Cancer.

Background: Although investigating the probable side effects of post intraoperative radiotherapy wound fluid secretion (PIWFS) is crucial, especially in clinical cases, no report has been published on the effect of PIWFS on the remaining tumor cells (in the vital state) in cavity side margins or surrounding regions. These tumor cells might be directly/indirectly exposed to intraoperative radiation therapy (IORT). Here, for the first time, we investigated the effect of PIWFS on tumor cells of the same patient extracted from the excised tumor in the spheroid form.

Methods: We generated 8 human-derived breast tumor spheroids from 4 patient specimens who received to IORT, dissociated and cultured them in microfluidic devices. The spheroids from each sample were treated with the patients' PIWFS and DMEM medium separately. Two different parameters, called area and number of detached cells (NDCs), were determined and investigated to evaluate the spheroids' vital and proliferative states.

Results: The results showed severe transformation in tumor spheroids' function into more invasive and proliferative functions after treatment with PIWFS.

Conclusion: Although the radiation-induced bystander effect may have a role in this observation, further experiments must be done to better clarify the probable desired or non-desired effects of post-IORT secretion for both the remaining tumor cells and the surrounding immune cells.