Metastatic Cancer

In a weird and deadly twist, cells thought to protect against cancer may actually promote it. Macrophages, a component of our immune system, should help fight and kill cancer cells. Instead there's recent evidence that these macrophages, or at least a subpopulation of them, actually help malignant cancer cells spread to distant sites in a process called metastasis.

According to a press release from the Albert Einstein College of Medicine, Jeffrey W. Pollard, Ph.D., one of their research professors, has shown that macrophages can act at the primary tumor site to enhance tumor progression and malignancy. So they've shown that macrophages can essentially become traitors, enhancing the worst aspect of cancer... metastatic tumor growth.

According to the press release:

Dr. Pollard and his colleagues propose that their discovery offers a potentially useful new target for anti-cancer therapy. What they've found is a vulnerable step in the cancer process that might be blocked by drug treatments. In three different ways, the scientists showed that metastatic tumor growth is inhibited if these unusual macrophages are killed.

They also showed that even after breast cancer cells have lodged in the animals' lungs and started aggressive growth, erasing the special macrophages dramatically slowed growth of the metastasized tumors. "This suggests that anti-macrophage therapy will have an impact in patients even with metastatic disease," Dr. Pollard said.

If you want to read the August 10th article publishing this research, it's on PLos. Just click here.

It's scary stuff. But it also is interesting to me since we're currently investigating a drug that suppresses the immune system. It seems to have a negative effect on breast tumor growth and that's counter intuitive. The immune system is supposed to help control cancer, so you'd expect that suppressing immune function would result in cancer spreading faster. This paper could explain why we're getting the results that we are.