Bicarbonate increases tumor pH and inhibits spontaneous metastases.

Abstract
The external pH of solid tumors is acidic as a consequence of increased metabolism of glucose and poor perfusion. Acid pH has been shown to stimulate tumor cell invasion and metastasis in vitro and in cells before tail vein injection in vivo. The present study investigates whether inhibition of this tumor acidity will reduce the incidence of in vivo metastases. Here, we show that oral NaHCO(3) selectively increased the pH of tumors and reduced the formation of spontaneous metastases in mouse models of metastatic breast cancer. ...https://www.ncbi.nlm.nih.gov/pubmed/19276390
 http://cancerres.aacrjournals.org/content/69/6/2260.full-text.pdf