Antigens that are selectively or abundantly expressed in cancer cells have been used for clinical trials, mostly in patients with advanced disease, and appear to be better vaccines than whole cells. Candidate vaccines have emerged from different categories of cancer antigens. Strategies involving various forms of peptides have been used either alone or combined with different cytokines, adjuvants or dendritic cells to enhance specific immune responses. Although individual patients have benefited, no strategy has emerged as universally applicable; neither has any route of administration. Increasingly sensitive methods have correlated clinical responses with measurable immune responses to vaccination in some patients.