A growing body of evidence suggests that intractable pain is associated with a decreased survival rate with a reduced quality of life in cancer patients. Recently, early palliative care has been shown to dramatically improve the survival rate of cancer patients. The tumor microenvironment refers to the cellular environment in which the tumor exists, including surrounding blood vessels, immune cells, fibroblasts and sensory neurons. Among those, the vascular and nervous systems share some critical guidance molecules. These comprehensive functions may ultimately affect tumor aggravation. It is of interest to note that the release of neurotransmitters including many of growth factors from sensory nerves could lead to neurogenic inflammation and may result in tumor progression. Therefore, we hypothesize that the activation of sensory nerves may contribute to tumor aggravation via the tumor microenvironment. In this session, we will introduce recent critical findings that could prove this hypothesis and discuss the possible mechanism of tumor growth associated with pain.