A paradox of tumor immunology is that so-called immune surveillance against cancer is a real and important phenomenom. Cancer is much more common in immunosuppressed people. Is the cancer a result of immunosuppression or does the cancer occur as a result of the same thing which caused the immunosuppression? The immune system is obviously very important, and major efforts should be made to harness the immune system in cancer therapy. It is a natural approach to cancer therapy.

In the 1960s, tumor immunology was probably the hottest field in cancer
research. Then, once again, in the early 1980s, with the work of Rosenberg at the NCI with IL-2 and "LAK" and "TIL" cells. But, despite enormous efforts, it remained true that probably for every cancer patient cured with immunotherapy, a thousand had been cured with regular old toxic chemotherapy. That's what's paradoxical.

On such tumor immunotherapy study that was prematurely abandoned during the early 90's was a concept of in situ cancer vaccination based upon studies of biologic response modifiers in an assay. Preliminary results found a striking association between the activity of biologic response modifiers which activate macrophages and the prior treatment status of patients with breast and ovarian cancers.

Effective chemotherapy produced a massive release and processing of tumor antigens, which led to a state in which the human immune system, via in situ cancer vaccination, responded to exogenous macrophage activation signals with potent and specific anti-tumor effects.

It's good to see the resurgence of aggressive cancer vaccine research. The choice of researchers to integrate promising insights and methods remains an essential component of new paradigms of cancer treatment.