Serum prolactin responses to TRH in recurrent breast cancer patients

The response of serum prolactin (PRL) to thyrotropin-releasing hormone (TRH) was evaluated by radioimmunoassay in 6 normal women and 44 breast cancer cases. They were divided into the following 5 groups: group 1:6 normal women; group 2:10 preoperative patients with early breast cancer; group 3:13 preoperative patients with advanced cancer; group 4:13 postoperative patients with no recurrence of cancer for more than 2 years; group 5:8 postoperative patients with cancer recurrence. The maximum increment of serum PRL levels following the administration of TRH was significantly higher in groups 2, 3 and 5 than in groups 1 and 4. These results indicate that patients with recurrent breast cancer have a higher PRL response to TRH than those without recurrence of cancer.