Elevated prolactin levels in bronchogenic carcinoma.

The frequency and significance of hyperprolactinemia was studied in 21 consecutive, untreated male patients with bronchogenic carcinoma. Seven patients (33%) were found to have elevated serum prolactin (hPRL) levels. No correlation was demonstrated between increased hPRL levels, tissue histology, or tumor burden. L-dopa suppression and/or TRH stimulation tests were obtained in three untreated patients with hyperprolactinemia. The results of these tests were considered normal suggesting hypothalamic control.