Studio pilota per un nuovo protocollo combinato di terapia in paziente con adenocarcinoma prostatico ormonorefrattario metastatico: docetaxel e 153 Sm-EDTMP.

Background Bone metastases are responsible for most of the morbidity associated with hormone-refractory prostate cancer (HRPC). 153Sm-EDTMP has been approved for palliation of painful skeletal metastases. We investigated the possible synergistic effect on tumor response and survival of 153Sm-EDTMP and a taxane-based chemotherapy regimen, that represents the standard of care for this stage of disease. Methods Thirty HRPC patients were enrolled, with a mean age of 70 years. All patients had metastatic bone disease; the extent of bone involvement was evaluated by means of a new bone scan scoring system. All patients received 153Sm-EDTMP (37 MBq/kg i.v.) first; Docetaxel (75 mg/sqm i.v. every 21 days) was administered after recovery of marrow toxicity. Results More than 70% of patients showed some response to treatment (complete response+partial response+stable disease). Mean time-to-progression was 8 months, while overall survival had a median of 18 months, and until 30th May 2009 five patients are still alive. Haematological toxicity observed both after 153Sm-EDTMP and Docetaxel was acceptable: only one patient showed G4 leucopoenia, one patient presented a G4 neutropoenia, and five G3 neutropoenia, all of them after 153Sm-EDTMP; after Docetaxel only one patient showed G3 anemia. We did not find a statistically significant correlation between bone lesions (using bone scan scoring system) and clinical results. The mild increase of the mean scan score after treatment most likely reflects the state of increased bone remodelling, in the perspective of a global stability of illness. Conclusion The results of this study confirm that 153Sm-EDTMP and Docetaxel in combination are effective on tumor response and overall survival, although inducing moderate haemopoytic toxicity. This work provides the rationale for further investigations regarding the combined therapeutic strategies