Towards a long-lasting immune prevention of HER2 mammary carcinomas: directions from transgenic mice.

Several theoretical and practical issues differentiate immune prevention from tumor immune therapy. The latter seeks to induce a rapid reaction against a life-threatening tumor, whereas prevention is dictated by the need to maintain constant surveillance of a situation in which an event is foreseen, but may not occur. The time frame of successful prevention is therefore long and often lifelong. Time itself is thus a key factor in the elaboration of vaccines to prevent tumor growth and its great length in preventive management poses new immunological problems that cannot be studied in short-term vaccination-challenge experiments. Many recent data indicate that HER2 receptor displays several features of an ideal tumor associated antigen and that an immune response can significantly alter HER2 tumor progression. We are thus using vaccination in the immune prevention and cure of carcinomas in HER2 transgenic mice in the search for a rationale for the application of preventive and curative vaccination for patients with HER2/ErbB-2 neoplastic lesions or at risk of recurrence after successful surgery. The design of effective immunopreventive approaches that can be translated to human situations is an important issue. A molecularly defined, effective and validated anti HER2 vaccine and the definition of immune mechanisms leading to the inhibition of HER2-driven neoplastic proliferation may provide a new way of treating these patients.