CASTRATION-INDUCED LYMPHOCYTOSIS IN PROSTATE-CANCER - POSSIBLE EVIDENCE FOR GONAD THYMUS ENDOCRINE INTERACTION IN MAN

Prompted by evidence from animal studies that castration produces lymp hocytosis associated with thymic hyperplasia, this paper has reviewed serial lymphocyte levels in patients with prostate cancer undergoing h ormone treatment. On day 7, 5 of 12 patients (58%) showed diminished c irculating lymphocyte levels (compared to day 0) reflecting the surge of testosterone after treatment with LHRH analogues, while on day 28 a reversal had occurred and 13 of 17 (77%) had increased lymphocytes (c ompared to day 0). Possible relevance of these observations to definin g a subgroup of patients with hormone-sensitive cancer who might benef it from immunotherapy is discussed.