Response of T lymphocyte populations in prostate cancer patients undergoing radiotherapy: influence of neoajuvant total androgen suppression.
BACKGROUND
This study sought to better define the immunological impact of combining neoadjuvant total androgen suppression (TAS) with radiotherapy (xRT) in treating prostate cancer.


METHODS
Subjects selected (n = 37) were stage I-II prostate cancer patients meeting the eligibility requirements for RTOG protocols 94-08 or 94-13. Flow cytometric monitoring of circulating T helper (Th), T suppressor/cytotoxic (Ts), natural killer (NK) and B lymphocytes was performed weekly.


RESULTS
Significant reduction of all lymphocyte subsets occurred as a result of xRT. Comparison between treatment groups demonstrated that the B lymphocyte and NK lymphocyte radioresponse was not influenced by TAS, but the Th and Ts lymphocyte response was, with addition of TAS leading to less radiation-induced decline.


CONCLUSIONS
The basis for this T cell response is unclear, but may involve a TAS-induced reduction of testosterone's immunomodulation of T cell proliferation and apoptosis and/or a direct, TAS-induced thymic stimulation. Our data suggest that addition of TAS to xRT appears to have no detrimental effects on lymphocyte subsets, and, indeed, may have favorable effects on T cells.
Johnke
Roberta M
RM
Department of Radiation Oncology, East Carolina University Brody School of Medicine, Greenville, North Carolina 27858, USA. tracyr@mail.edu.ecu
Edwards
Judy M
JM
Kovacs
Charles J
CJ
Evans
Mark J
MJ
Daly
Barbara M
BM
Karlsson
Ulf L
UL
Lee
Tung-Kwang
TK
Allison
Ron R
RR
Arastu
Hyder H
HH
Cariveau
Mickael J
MJ
O'Brien
Kevin F
KF
D000368:Aged; D000726:Androgen Antagonists / Q000008:administration & dosage; D018931:Antineoplastic Agents, Hormonal / Q000008:administration & dosage; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D005485:Flutamide / Q000008:administration & dosage; D017273:Goserelin / Q000008:administration & dosage; D006801:Humans; D008213:Lymphocyte Activation; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009367:Neoplasm Staging; D011471:Prostatic Neoplasms / Q000188:drug therapy / Q000276:immunology* / Q000532:radiotherapy / Q000628:therapy*; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology* / Q000528:radiation effects
D000726:Androgen Antagonists; D018931:Antineoplastic Agents, Hormonal; D017273:Goserelin; D005485:Flutamide