The invention relates to the use of agents that alter the peritumoral environment, specifically non-peptide NK1 receptor antagonists, for the treatment of cancer. The peritumoral environment is formed by the stromal cells, the stromal matrix, intra- and peri-tumoral vascularization and the cells responsible for the inflammatory and/or immune response around the tumor. The result of the alteration to the peritumoral environment is a reduction in the size of the tumor, the prevention of its development and, optionally, the induction of its disappearance. The invention also relates to pharmaceutical compositions containing said peritumoral-environment-altering agents, either alone or combined with at least one other active ingredient, for the treatment of cancer.
