Breast cancer remains the most frequently diagnosed cancer in women worldwide, with conventional treatments often limited by serious side effects and therapeutic resistance. In recent years, the ability of various helminths and derived products to suppress cancer growth has been well documented both in humans and experimental models.  We aimed to investigate the potential antitumor effects of Echinococcus granulosus hydatid fluid (HF), known for its immunomodulatory properties, in a cell-derived breast cancer xenograft model (CDX).

In this sense, immunosuppression was first induced in Wistar rats using cyclosporine A (CsA). Subsequently, treatment with HF was followed by xenografting of human HEP2 tumor cells. Key parameters monitored throughout the experimental protocol included the rats’ general health, body weight, circulating immune cell populations, nitric oxide (NO) levels, and interleukin-6 (IL-6) production.

HF treatment resulted in notable changes in the rats' general health and immune responses. Treated rats showed improved weight regain, increased monocytes and neutrophils counts, and NO/IL-6 production, indicating enhanced immune response activation. Remarkably, only 20% of HF-treated rats developed tumors, compared to 80% in untreated rats, with a significant reduction in tumor size. Additionally, HF-treated rats showed lower levels of  hepatic transaminase, indicating reduced toxicity.  

These results suggest that hydatid fluid not only enhances immune response but also effectively inhibits tumor growth with minimal toxicity. This study highlights the potential of hydatid fluid as a promising therapeutic approach for breast cancer. Further research is recommended to understand molecular mechanisms underlaying hydatid fluid’ effects. This new antitumor strategy could open new horizons in the development of highly immunogenic anticancer vaccines.