Removing the spleen may help fight leukemia, mouse model suggests

Early surgical removal of the spleen combined with antiangiogenic cancer therapy may halt the progression of leukemia, according to scientists at Sunnybrook and Women’s College Health Sciences Centre.

The research, published today in Blood, is the first to show the combination of two factors secreted from the environment of the spleen is important in the promotion of leukemia.

Dr. Yaacov Ben-David, a Senior Scientist in Molecular and Cellular Biology at the Sunnybrook & Women’s Research Institute who is the lead investigator in the study and colleagues, including Dr. Yuval Shaked, a post-doctoral fellow, discovered that the spleen of diseased mice provides a supportive environment for cancer cells. The spleen secretes various factors, among them MCP and VEGF, which relate to the immune system and promote formation of new blood vessels. Secretions of these factors cause leukemic cells in the spleen to multiply. In this study, Dr. Ben-David’s team showed that these factors might contribute to the progression of breast and other types of cancer.

“For the first time we have been able to provide evidence that the environment around the spleen may play a critical role for patients with leukemia and possibly other types of cancers,” says Dr. Ben-David who is also an Associate Professor of Medical Biophysics at the University of Toronto. “When combined with antiangiogenic cancer therapies that work by halting the development of new blood vessels that feed tumor growth, we found that mice experienced prolonged survival.”

In the human body, the spleen is located in the upper left side of the abdomen, behind the stomach. Its functions are to filter blood, remove bacteria and make and store blood. Since it is involved in so many bodily functions, it is vulnerable to a wide range of disorders. Any condition that infects the spleen, such as leukemia, can place great strain on the organ and cause it to enlarge. The human body can adapt well to life without this organ, so surgically removing a diseased or damaged spleen is worth further investigation.

Researchers suggest that early surgical intervention by removing the spleen and suppressing the related factors might be considered as a treatment model for human hematological malignancies, cancers of the body’s blood-forming and immune systems. Since the research was conducted on mice and does not apply to humans, further research and clinical trials are required before this is practice will be considered as a treatment option in the clinic.