Expert opinion: Obesity and the increased risk of aggressive prostate cancer
It is now well established that obesity increases the risk of cancer, although far less is known about the influence of obesity on the course of the disease once it has been diagnosed.
In the case of prostate cancer though, it has been shown that the presence of a large amount of fat around this organ increases the risk that the tumor will quickly extend beyond the prostate. Now, in a recent study published in Nature Communications, Catherine Muller and her colleagues have shown that this might be related to the ability of fat cells to release a specific protein, called CCL7, which can bind to another protein, CCR3, on the surface of prostate cancer cells.
The binding of CCL7 to CCR3 promotes the ability of prostate cancer cells to migrate, at least in cell culture experiments, and when this is blocked by an antibody that binds to CCL7 the movement of the prostate cancer cells is correspondingly inhibited. In addition, the researchers showed that prostate tumors in mice grew far larger when the animals were fed a high fat diet compared to those fed a standard diet, and this effect was blocked by preventing the tumor cells from having the CCR3 protein on their surface. Taken together, this is compelling evidence for a role of obesity in promoting the aggressive behavior of prostate tumors in mice, although it is rather less certain whether the same mechanism occurs in humans. Furthermore, it is difficult to see how the powerful experimental techniques used in this research can be translated to a medicine suitable for human patients in the near future. The group's findings do however underline the need to tackle obesity as an urgent public health issue.
, Professor of Molecular Oncology reacting to BBC News article.