Preoperative serum gastrin level: A prognostic indicator in metastatic gastrinoma

Experience has shown that gastrinoma is a tumor with a widely variable clinical course. Tumor resectability and the presence of metastases are important prognostic indicators, but a biochemical marker for aggressiveness of this lesion is currently lacking. Previous studies have suggested that preoperative gastrin levels, although important in diagnosis, have little significance with regard to outcome in the Zollinger-Ellison syndrome. These studies, however, have been compromised by small numbers and short follow-up. We hypothesized that preoperative serum fasting gastrin levels correlate with clinical course of this disease. We examined the medical records of all patients treated for this tumor at the Ohio State University Medical Center since the advent of the gastrin radio-immunoassay in the early 1970s (n = 53). Patients who died from causes other than their tumor were excluded. Preoperative fasting serum gastrin level of greater than 700 pg/ml predicted poor outcome in the case of gastrinoma with metastases present at diagnosis. Ten-year survival of patients with metastatic disease and preoperative gastrin > 700 pg/ml was only 16% (1/6), compared to 100% (4/4) 10-year survival among patients with metastatic disease but gastrin < 700 pg/ml (p < 0.01 by log-linear test). There were no significant differences between these groups with regard to age, sex, type of surgical procedure, presence of the MEN syndrome, or location of metastasis. Survival in the absence of metastases was also adversely affected by greatly elevated serum gastrin, though to a less severe degree. Ten-year survival in patients with gastrin > 700 pg/ml without metastases was 80% (8/10), whereas that in patients without metastases and gastrin < 700 pg/ml was 100% (10/10). The data indicate that in the Zollinger-Ellison syndrome, greatly elevated preoperative fasting serum gastrin level implies a poorer prognosis, particularly when metastatic disease is present at diagnosis. Patients in this group may require a more aggressive therapeutic approach, using adjuvant hormonal and chemotherapy in addition to surgery.