1. 1. Atopic disease occurs in patients with malignant tumors. 2. 2. The incidence of atopic disease in patients who suffer from malignancy appears to be significantly below the incidence of atopic disease in control groups of noncancerous patients and in the general population. 3. 3. In fourteen of thirty-eight atopic patients with cancer, atopic symptoms disappeared at least ten years prior to the recognition of the malignancy. 4. 4. The largest group of tumor patients, those who suffer from cancer of the uterus, prostate, and breast, show a particularly impressive decrease in the incidence of atopy. 5. 5. Ovarian cancer to date represents the one exception to the pattern which we have found.