Levels of alpha-subunits of gonadotropins can be increased in Zollinger-Ellison syndrome, both in patients with malignant tumours and with apparently benign disease.

To evaluate the value of intact hCG, the beta-subunit of hCG and the common alpha-subunit of the glycoprotein hormones as tumour markers in patients with gastrinomas, we investigated 30 patients with the Zollinger-Ellison syndrome. Fifty-seven percent of the patients with malignant disease (N = 7) and 45% of those with active and apparently benign disease (N = 20) had raised values of circulating alpha-subunit. Detectable levels of hCG or hCG-beta were found in 7 patients of whom 4 had malignant disease. Radical tumour resection in 2 patients resulted in normalisation of elevated levels of alpha-subunit, and in one patient who developed metastases, the alpha-subunit values became elevated simultaneously. By chromatographic studies we found that the alpha-subunit-like reacting substance in serum eluted as the normal free alpha-subunit in 8 patients, but in one patient with metastatic disease we found evidence for production of a larger molecular form of alpha-subunit. The results indicate that the common alpha-subunit is a valuable tumour marker in patients with gastrinomas, whereas hCG-beta is only seldomly elevated. Single estimates of any of the hormonal fragments seem not to relate with malignancy, whereas a rise in alpha-subunit concentration in some patients may be related to the development of malignancy.