Background: Treatment options for patients with metastatic breast cancer should be both as effective and preferably as little toxic as possible. However to date there is no standard therapy available but treatment regimens for metastatic breast cancer vary much. Locoregional hyperthermia might show additive effects to chemotherapy due to an increased perfusion and a simultaneous occurring of interstitial acidosis in tumor tissue.
Methods: Primary objective of the multicenter prospectively randomized phase I/II German Mammatherm-trial is to evaluate if metastatic breast cancer patients benefit from locoregional hyperthermia given additionally to a chemotherapy regimen regarding progression free survival. Phase I of this study is a dose-finding-study for liposomal doxorubicin administered in combination with locoregional hyperthermia. Dose-escalation-levels are at 40/50/60 mg/m2 and in each level 3 patients have to be treated without showing severe toxicity. The first eligible patient (i.e. metastatic lesions accessible to locoregional hyperthermia) entered the study in August 2007 and 9 more patients are needed until the study can proceed to phase II. Phase II (recruitment of 300 patients planned) will compare 2 different treatment regimens in a randomized setting: Arm A comprises 6 cycles of liposomal doxorubicin 40/50/60 mg/m2 (final dose to be defined after phase I) i.v. d1 q22dx6 and cisplatin 20 mg/m2 i.v. d1, 8, 15 q22dx6 in combination with locoregional hyperthermia administered at d1, 4, 8, 11, 15, 18 q22dx6. In arm B patients are treated according to the same chemotherapy regimen but without adding the hyperthermic treatment.
Results: Intentions of the study are that patients in the experimental arm will benefit from locoregional hyperthermia administered additionally to chemotherapy, i.e. that progression free survival as well as overall survival (as secondary study objective) can be prolonged significantly without being accompanied by increased toxicity or reduced quality of life. First results for phase I are expected by the end of 2008.
Conclusions: The Mammatherm-trial will show if metastatic breast cancer patients have a prolonged progression free survival by adding locoregional hyperthermia to a chemotherapy regimen.