Pinning of tumoral growth by enhancement of the immune response.

Tumor growth is a surface phenomenon of the molecular beam epitaxy universality class in which diffusion at the surface is the determining factor. This Letter reports experiments performed in mice showing that these dynamics can, however, be changed. By stimulating the immune response, we induced strong neutrophilia around the tumor. The neutrophils hindered cell surface diffusion so much that they induced new dynamics compatible with the slower quenched-disorder Edwards-Wilkinson universality class. Important clinical effects were also seen, including remarkably high tumor necrosis (around 80%-90% of the tumor), a general increase in survival time [the death ratio in the control group is 15.76 times higher than in the treated group (equivalent to a Cox's model hazard ratio of 0.85; 95% confidence interval 0.76-0.95, p=0.004)], and even the total elimination of some tumors.