The present application discloses the preparation and use of attenuated tumor-targeted bacteria vectors for the delivery of one or more primary effector molecule(s) to the site of a solid tumor. The primary effector molecule(s) of the invention is used in the methods of the invention to treat a solid tumor cancer such as a carcinoma, melanoma, lymphoma, or sarcoma. The invention relates to the surprising discovery that effector molecules, which may be toxic when administered systemically to a host, can be delivered locally to tumors by attenuated tumor-targeted bacteria with reduced toxicity to the host. The application also discloses to the delivery of one or more optional effector molecule(s) (termed secondary effector molecules) which may be delivered by the attenuated tumor-targeted bacteria in conjunction with the primary effector molecule(s).