A new study has found that a “soil and seed” approach may offer a simple and effective treatment for patients with metastatic solid tumors of visceral organs such as the liver, kidney, lung and brain. The study is published in the September issue of Radiology.
While a major issue in cancer therapy relates to identifying appropriate targets, Junjie Li, MD, University of Leuven in Belgium, and colleagues suggest that a dual-targeting strategy creates a harsh microenvironment impossible for cancer to survive in.
“Instead of directly attacking cancer cells, or seeds, that have proved hard to target, we chose to firmly hit two stable intratumoral targets that are not cancer cells, but are closely associated with them in both functionality and location,” wrote Li et al.
Researchers implanted 48 liver rhabdomyosarcomas in 24 rats, which were split into four groups for drug administration. Researchers injected a vascular-disrupting agent (CA4P) to cause tumor necrosis as well as a necrosis-avid agent (I-hypericin) 24 hours later in the dual-targeting group. Results were then compared to control groups using MRI and other techniques.
The scientists found that after eight days post treatment, the tumor volume of the rhabdomyosarcoma in the vehicle-control group was double that in both single-targeting groups, and was five times that in the dual-targeting group. Additionally, tumor doubling time was significantly lower in the dual-targeting group.
While promising, further studies will be necessary, the authors noted, and diffuse malignancies, such as leukemia, are not suitable for the technique.
“To verify the reproducibility of the above findings from rat rhabdomyosarcoma liver tumor models, multicenter studies on this approach are underway using other tumor models,” wrote Li et al. “Similar encouraging results are being generated.
“In summary, this dual-targeting approach appears to be a more natural, versatile, and relatively simple anticancer strategy that allows higher targeted-radiation delivery and greater probability of complete tumor response,” they concluded. “The concept has been preliminarily proved with experimental evidence from rodent models."