Modulation of chromatin structure regulates cytokine gene expression during T cell differentiation

Brachytherapy boost with external radiation therapy (RT) allows safer delivery to the prostate than conventional techniques. We measured the degree of radiation effect of adenocarcinoma cells in post-RT biopsy specimens and the association with biochemical failure. Forty-six patients with T2b-3c adenocarcinomas underwent 18-month post-RT biopsies, of whom 22 had adenocarcinoma. All biopsy specimens without obvious adenocarcinoma were stained with antibodies to prostate-specific antigen and keratins AE1/AE3 and 34 beta E12. The RT effect to adenocarcinoma cells was scored by adding the scores of the nuclear and cytoplasmic changes. Each adenocarcinoma was assigned 2 scores; the most-common and the least-amount RT effect. Treatment for 7 of the 46 patients failed; 6 of these had residual adenocarcinoma on the post-RT biopsy specimen. Sixteen of 22 patients with adenocarcinoma on the post-RT biopsy specimen did not experience biochemical failure. The presence of adenocarcinoma on the post-RT biopsy specimen was significantly associated with failure. The mean most-common RT-effect score for the 16 patients without failure was 5.2 compared with 4.2 for the 6 patients with failure. The mean least-amount RT-effect score in patients without failure was 4.4 compared with 2.8 (range, 2-4; SD, 0.75) in the failure group. These relatively radiation-resistant foci may be the source of failure. Scoring the RT-effect of adenocarcinoma in post-RT biopsy specimens may be clinically useful in predicting subsequent biochemical failure.