The normal protocol when chemotherapy is administered to men who have androgen-independent prostate cancer (AIPC) is to continue the androgen deprivation program despite its failure to any longer suppress the cancer’s growth. A study published by the Department of Medical Oncology, St Bartholomew’s Hospital, London, UK, examined whether it was possible to re-induce hormone sensitivity in previously castrate AIPC patients by stopping the blockade during chemotherapy.
This phase II prospective study evaluated the effects of modifying this normal protocol by stopping the hormone blockade during the administration of the oral chemotherapy drugs. Forty-three of the fifty-six AIPC patients who participated in the study were restarted on a hormone blockade of diethylstilbestrol (DES) and dexamethasone after the regime of chemotherapy drugs was completed. All patients were castrate at the start of chemotherapy.
The median overall survival for these 43 patients from the time of restarting the blockade was 7.7 months (95% confidence interval (CI): 3.7-10.9 months). Sixteen (37%) patients had a 50% PSA response to treatment, which was associated with improved overall survival (14.0 months vs 3.7 months P=0.003). Eight out of 12 patients who did not respond to diethylstilbestrol before chemotherapy did so post chemotherapy.
It does seem possible for re-induction of hormone sensitivity after chemotherapy. Additional research is needed to both replicate this study and see if this type of hormone manipulation could also be successful with other types of blockade drugs.
Published in AIPC.British Journal of Cancer (2008) 98, 22-24. doi:10.1038/sj.bjc.6604051 www.bjcancer.com Published online 8 January 2008.
Joel T. Nowak MA, MSW