Abstract: Provided are immunotherapeutic compositions and methods for the treatment of cancers characterized by the presence of moderately to well-differentiated cancer cells. Exemplary immunotherapeutic compositions employ antigen presenting cells, including dendritic cells, activated by a protein conjugate such as fusion proteins including a prostatic acid phosphatase/granulocyte-macrophage colony stimulation factor fusion protein. Also disclosed are methods for assessing the susceptibility of cancer cells to treatment regimens employing one or more immunotherapeutic composition.