Evaluation of cellular immunologic responsiveness in the clinical management of patients with prostatic cancer. II. Effect of oestrogen, cryosurgery and transurethral resection on thymic-dependent lymphocytic blastogenesis.

The effect of oestrogen, cryosurgery and transurethral resection (TUR) of the prostate on the blastogenic response of thymic-dependent peripheral blood lymphocytes (PBL) to the non-specific mitogen, phytohaemagglutinin (PHA) was evaluated as one in vitro criteria of each of these treatment modalities on the cellular immunologic responsiveness of 24 patients with prostatic cancer. A depression 5 days following receipt of oestrogen and 2-7 days following cryosurgery or TUR of the responsiveness of PHA-stimulated PBL was observed. Oestrogen-induced aberrations of responsiveness may not only be of relevance in prostatic cancer patients, but also suggested association between uterine cancer and prolonged administration of diethylstilboesterol and the development of vaginal tumours in offspring found in association with maternal ingestion during pregnancy. Particularly striking was that contrary to the reduced responsiveness of PBL cultured in autologous and homologous serum from patients receiving TUR, patients receiving cryosurgery, while also showing reduction in autologous serum, showed increased responsiveness when cultured in homologous serum. Although transient, depression of lymphocyte responsiveness, particularly if involving tumour-cloned T cells, may provide reduced surveillance to potential tumour cells leading to an alteration of tumour-host homeostasis. The potential of reduced tumour surveillance at least in the case of TUR, appears to be supported by observations that patients expiring from prostatic cancer at our institution had an antecedent TUR. The possibility of identifying those patients possessing aberrations of responsiveness prior to therapy, as well as those prone to develop or undergo further reduction in their responsiveness following the presently evaluated treatment modalities would appear to be of real and relevant concern in the management of the patient with prostatic, as well as other types of malignant neoplasms. The possibility of pre-operative and/or post-operative immunotherapy in such patients may be indicated pending further study.