The substance P/neurokinin-1 receptor (SP/NK-1R) system regulates several cell signaling pathways involved in cancer progression. These pathways are the following: (a) Antiapoptotic signaling pathway (PI3K/Akt/mTOR); (b) cell proliferation signaling pathway (PKC, MAPKs, ERK); (c) cell migration signaling pathway (Rho-ROCK-pMLC); (d) Wnt signaling pathway (β-catenin, c-myc, cyclin D1); (e) AC-cAMP-PKA phosphorylation signaling pathway, and (f) the Warburg effect (GSK-3β). APC: Adenomatous polyposis coli; Dvl: Dishevelled; Fzd: Frizzled receptor; PCP: Planar cell polarity pathway; PDK-1: Phosphoinositide-dependent kinase-1; pMLC: Myosin light-chain kinase; TCF/LEF: Transcription factor/lymphoid enhancer-binding factor.