Efficacy of Hypotonic Cisplatin Treatment After Marginal Resection of Fibrosarcoma: A Preliminary Report

<h3>Background/Aim:</h3> If a malignant soft tissue tumor is located close to important nerves or blood vessels, surgical margins often have to be reduced. Additionally, the specific procedure after the non-radical surgery is needed. Lavage with distilled water is often conducted to prevent local recurrence, while little reports have been published about this procedure. The aim of this study was to validate the efficacy of hypotonic cisplatin treatment after marginal resection. <h3>Materials and Methods:</h3> We investigated whether exposure to platinum derivatives under hypotonic conditions more efficiently decreases the viability of human fibrosarcoma (HT-1080) cells <i>In vitro</i> by comparing six conditions: PBS only (control), short (10 min) exposure to cisplatin, short exposure to hypotonic distilled water and cisplatin, and continued exposure to distilled water alone, continued exposure to cisplatin alone, and continued exposure to hypotonic distilled water and cisplatin. Furthermore, <i>in vivo</i>, female severe combined immunodeficient (SCID) mice were implanted with HT-1080 tumor cells in the back muscle. One week later, the xenograft model was assigned to four groups to evaluate overall survival: control (no treatment), hypotonic treatment (distilled water exposure after surgery), cisplatin treatment (cisplatin exposure after surgery), and hypotonic cisplatin treatment (hypotonic cisplatin exposure after surgery). <h3>Results:</h3> <i>In vitro</i>, while HT-1080 tumor cells continued to proliferate after short exposure to hypotonic cisplatin, continued exposure resulted in a significant decrease in cell proliferative ability. Furthermore, <i>in vivo</i>, overall survival was significantly prolonged in the hypotonic cisplatin treatment group compared with the other groups. <h3>Conclusion:</h3> The combination of hypotonic distilled water and cisplatin may represent a promising intraoperative treatment after fibrosarcoma resection.