Transurethral systems and methods for ablation treatment of prostate tissue

A system for preferential destruction of cancerous or proliferating cells of a target tissue or of a body lumen passing through a target tissue of a patient, comprising:

• an elongate probe comprising a proximal end and a distal portion having an expandable member, the expandable member comprising one or more conductive electrode elements, the distal portion positionable in a body lumen of the patient;
• one or more secondary electrodes positionable within or adjacent to the target tissue and spaced from the electrode elements of the expandable member;
• and
• a control system comprising a power source, the control system coupled to the elongate probe and secondary electrode(s) and configured to provide electrical current to the probe and electrode(s) so as to establish a current flow through a volume of the patient's target tissue and between the electrode elements of the probe positioned in the body lumen of the patient and the positioned secondary electrode(s).