Blood histamine and solid malignant tumors.

A clinical study was performed to determine whether patients with a newly diagnosed solid malignant tumor manifest an alteration in whole-blood histamine levels. Our results indicate that such patients have blood histamine nearly three times greater than either normal, healthy individuals or noncancerous disease controls. Following surgical removal of the tumor, blood histamine levels remained high for 2 months and then dropped close to the normal range 3 months after surgery. Basophil counts did not change significantly in the presence of a malignant tumor. Patients receiving either chemotherapy or radiation therapy, and terminal cancer patients who were no longer receiving any therapy except for pain control had blood histamine within or below the normal range. By analogy with animals studies, we suggest that nascent histamine synthesis is increased in the presence of a developing tumor. The clinical usefullness of this observation remains to be determined.