An explanation of the variable clinical response to interleukin 2 and LAK cells.

Adoptive immunotherapy for the treatment of cancer has met with limited but, for some, encouraging success. A minority of malignant melanoma and renal cell carcinoma patients respond to therapy with interleukin 2 (IL-2) or IL-2 plus lymphokine-activated killer (LAK) cells. The mechanism of response, and the reasons for the variation within disease groups, is not clear. In this article, Giorgio Parmiani proposes that successful adoptive therapy is dependent on the recruitment of activated host antitumor T lymphocytes and suggests that this explains the greater efficacy of tumor-infiltrating lymphocytes in combating melanoma and renal cell carcinoma.