Thesis (doctotral)--München, 1983.

Zugl.: Berlin, Charité, Universiẗat-Med., Diss., 2006.

München, Techn. Universiẗat, Diss., 2007.

Purpose: Platinum chemotherapy can be considered to treat metastatic castration-resistant prostate cancer (mCRPC) with features of neuroendocrine differentiation. However, platinum compounds are generally only applied after the failure of multiple prior-line treatment options. This study investigated whether acquired resistance against ionizing radiation or docetaxel chemotherapy—two commonly applied treatment modalities in prostate cancer—influences the cisplatin (CDDP) tolerance in mCRPC cell line models. Methods: Age-matched parental as well as radio- or docetaxel-resistant DU145 and PC-3 cell lines were treated with CDDP and their sensitivity was assessed by measurements of growth rates, viability, apoptosis, metabolic activity and colony formation ability. Results: The data suggest that docetaxel resistance does not influence CDDP tolerance in all tested docetaxel-resistant cell lines. Radio-resistance was associated with sensitization to CDDP in PC-3, but not in DU145 cells. In general, DU145 cells tolerated higher CDDP concentrations than PC-3 cells regardless of acquired resistances. Furthermore, non-age-matched treatment-naïve PC-3 cells exhibited significantly different CDDP tolerances. Conclusion: Like patients, different mCRPC cell lines exhibit significant variability regarding CDDP tolerance. The presented in vitro data suggest that previous radiation treatment may be associated with a moderate sensitization to CDDP in an isogenic and age-matched setting. Therefore, previous radiotherapy or docetaxel chemotherapy might be no contraindication against initiation of platinum chemotherapy in selected mCRPC patients.

There is increasing interest in the use of adjuvant hormonal therapies, which are given after the resection or destruction of all gross disease, in early-stage prostate cancer, as a significant proportion of patients experience progression and/or die from the disease despite undergoing therapy with curative intent. Several retrospective studies suggest that adjuvant hormonal therapy may improve long-term outcome after radical surgery in men with positive lymph nodes, although this approach has yet to be studied in a prospective setting. No studies of adjuvant therapy for patients with extracapsular extension at surgery have been completed, but in an interim analysis of an open controlled trial, adjuvant flutamide significantly improved progression-free survival at 4 years. Three prospective studies in the radiotherapy setting have shown that adjuvant luteinizing hormone-releasing hormone (LH-RH) agonist therapy significantly improves progression-free and/or overall survival. Future studies need to define patient subgroups who will benefit most from adjuvant therapy. The side effects of the different therapeutic options also need to be compared. It is hoped that many of the outstanding questions concerning adjuvant hormonal therapy will be answered by the ongoing Bicalutamide Early Prostate Cancer Programme. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.