Metastasis enables cancer cells to migration, which is responsible for most cancer-related deaths. It usually begins with local invasion to the surrounding tissues, followed by intravasation into the lymph and blood microvasculature before the cancer cells finally colonize within the microenvironment of other locations in the patient's body. Recently, we discovered that gold nanorods assisted photothermal therapy (AuNRs-PPTT) inhibits cancer cell migration and prevent metastasis. AuNRs-PPTT is a therapy in which AuNRs are injected to a tumor before near-infrared light is transiently applied to the tumor producing localized heat. However, AuNRs-PPTT has great potential in replacing the current ineffective anti-metastasis treatments but most of the studies has been performed in vitro. The objectives of this study to understand the AuNRs-PPTT impacting blood and blood vessels in naturally occurring mammary glands tumor in cats and dogs. Our histopathology results showed AuNRs-PPTT caused infiltration of neoplastic cells into lymphatic vessels. Furthermore, we observed that AuNRs-PPTT significantly cause blood coagulation around the tumor, which could be incorporated in the surgery to decrease the bleeding and potentially avoiding the risk of metastasis caused by the surgery. This observation might explain why AuNRs-PPTT inhibited metastasis for mammary gland metastasis upon AuNRs-PPTT. After 24 months, the optimized doses of 2.5 nm of AuNRs irradiated by near-Infrared laser with 0.5 w/cm2 intensity for 2 minutes, have shown no any toxicity signs in liver and kidney functions.

Citation Format: Moustafa Ragab Khalil Ali. Gold nanorods-assisted photothermal therapy inhibits metastasis by decreasing the mammary tumors bleeding in canine and felines [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4183.