April 15th 2005
Androgen-deprivation therapy, usually with combined androgenblockade, is standard initial treatment for advanced prostate cancer.With failure of initial treatment, as indicated by rising prostate-specificantigen (PSA) levels, second-line hormonal therapy is usually instituted.Over the past several years, it has become increasingly clear thatsystemic chemotherapy has an important role in hormone-refractorydisease. Phase II trials have demonstrated high PSA and measurabledisease response rates with taxane single-agent and combination treatments.One recent phase III trial showed that docetaxel (Taxotere)/estramustine (Emcyt) significantly improved overall survival, progression-free survival, and PSA response rate compared with mitoxantrone(Novantrone) plus prednisone. Another phase III trial demonstratedthat docetaxel given every 3 weeks plus prednisone significantly improvedoverall survival, PSA response rate, pain relief response rate,and quality of life compared with mitoxantrone and prednisone. Onthe basis of these findings, every-3-week docetaxel plus prednisone isnow considered standard first-line therapy for metastatic hormonerefractorydisease. There is considerable optimism that treatment canbe further improved. Studies of taxane combinations with bevacizumab(Avastin), thalidomide (Thalomid), bortezomib (Velcade), antisenseBcl-2 oligonucleotide, mTOR inhibitors, epidermal growth factor receptorinhibitors, and KDR inhibitors are under way. Randomized phaseIII trials in progress or planned are examining docetaxel in combinationwith imatinib mesylate (Gleevec) or calcitriol and docetaxel/prednisonein combination with bevacizumab and an antisense clusterincompound. Other promising systemic agents include epothilones andatrasentan, and promising vaccines include Provenge, GVAX, andProstvac.