Decreased blood histamine levels in patients with solid malignant tumours.

In a one-year follow-up study, 444 blood histamine determinations were performed in 163 patients with solid malignant tumours. Compared with normal subjects, blood histamine levels were significantly lower in patients with unresected primary tumours (30.7 +/- 19.9 ng ml-1), metastases (34.1 +/- 17.1 ng ml-1), or both (24.5 +/- 12.8 ng ml-1). By contrast, after successful tumour resection, histamine blood levels were nearly normal (52.1 +/- 18.4 ng ml-1, versus 59.6 +/- 22.6 in control patients). Stability of the histamine blood levels was associated with stability of the disease. A progressive decrease in histamine blood levels preceded clinical relapse or detection of metastasis. In patients with consecutive histamine blood levels which were less than 15 ng ml-1, survival did not exceed 2 months. In patients with gastrointestinal tumours, blood histamine levels provided information additional to that derived from serum CEA determination. In patients with non-gastrointestinal tumours, the blood histamine level may be of more value than CEA as a marker of disease progression.