An intratumoral modulation therapy (IMT) method for the treatment of nervous system and systemic tumor in a patient which includes: (a) chronically implanting an electrode adjacent to or in the tumor of the patient or in a residual tumor bed, the electrode having electrical leads connected thereto and (b) generating electric stimulation and applying the electric stimulation through the electrical leads to the electrode adjacent to or within the tumor. A method of transferring genetic material to a tumor cell which includes: (a) positioning an electrode adjacent to the tumor cell, the electrode having electrical leads connected thereto (b) generating electric stimulation and applying the electric stimulation through the electrical leads to the electrode adjacent the cancer cell and (c) delivering the genetic material to the tumor cell treated with the continuous alternating electric stimulation.
