Controlled release formulation and minimally invasive method of administration to locally treat cancer

A method of treating a cancer comprising locally administering at a site of a subject in need thereof an effective amount of a controlled release formulation comprising naloxone and at least one pharmaceutically acceptable carrier comprising sodium alginate, gum Arabic, and lanthanum carbonate, wherein said controlled release formulation comprises naloxone in an amount of at least 11 mM and said controlled release formulation provides a release rate of naloxone of 0.075-mg/hr1/2 to 0.3-mg/hr1/2.