• Tetsuo Fujita, Bin S Teh, Terry L Timme, Wei-Yuan Mai, Takefumi Satoh, Nobuyuki Kusaka, Koji Naruishi, Elmoataz Abdel Fattah, Estuardo Aguilar-Cordova, E Brian Butler, and Timothy C Thompson.
• Scott Department of Urology, Baylor College of Medicine, Houston, TX, USA.
• Int. J. Radiat. Oncol. Biol. Phys. 2006 May 1; 65 (1): 84-90.

PurposeTo explore long-term immune responses after combined radio-gene-hormonal therapy.Methods And MaterialsThirty-three patients with prostate specific antigen 10 or higher or Gleason score of 7 or higher or clinical stage T2b to T3 were treated with gene therapy that consisted of 3 separate intraprostatic injections of AdHSV-tk on Days 0, 56, and 70. Each injection was followed by 2 weeks of valacyclovir. Intensity-modulated radiation therapy was delivered 2 days after the second AdHSV-tk injection for 7 weeks. Hormonal therapy was initiated on Day 0 and continued for 4 months or 2.3 years. Blood samples were taken before, during, and after treatment. Lymphocytes were analyzed by fluorescent antibody cell sorting (FACS).ResultsMedian follow-up was 26 months (range, 4-48 months). The mean percentages of DR+CD8+ T cells were increased at all timepoints up to 8 months. The mean percentages of DR+CD4+ T cells were increased later and sustained longer until 12 months. Long-term (2.3 years) use of hormonal therapy did not affect the percentage of any lymphocyte population.ConclusionsSustained long-term (up to 8 to 12 months) systemic T-cell responses were noted after combined radio-gene-hormonal therapy for prostate cancer. Prolonged use of hormonal therapy does not suppress this response. These results suggest the potential for sustained activation of cell-mediated immune responses against cancer.

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