Novel concept of antisurvival factor (ASF) therapy produces an objective clinical response in four patients with hormone-refractory prostate cancer: Case report
BACKGROUND. Osteoblasts and osteoblast-derived survival growth factors, such as insulin-like growth factor I (IGF I), inhibit chemotherapy apoptosis of prostate cancer cells, thereby producing cytotoxic drug-resistant tumor growth, in vitro. METHODS. We tested a novel therapeutic approach, referred to as antisurvival factor (AFS) therapy, that aimed at reduction of osteoblast-derived IGFs, using dexamethasone (4 mg per os, qD) and growth hormone (GH)-dependent liver-derived IGFs, using a somatostatin-analog (lanreotide, 30 mg, intramuscularly (IM), q14D) in combination with triptorelin (3.75 mg, intramuscularly, q28D) to produce a clinical response in 4 patients with progressing hormone-refractory prostate cancer. RESULTS. The patients given ASF therapy exhibited an excellent improvement of clinical performance and a decline of prostate-specific antigen (PSA) within 2 months of ASF therapy. One of them experienced excellent clinical response (normalization of PSA), two experienced good clinical response (decline of PSA of more than 50%), and one experienced stabilization (decline of PSA of less than 50%). CONCLUSIONS. We conclude that this novel concept of combination therapy, using ASF with hormone ablation, is a promising salvage therapy that should be further assessed with a randomized clinical trial
