Curative therapy for solid tumors often requires combined-modality treatment. In the following paper the importance of different strategies as prerequisite for organ salvaging tumor surgery and for successful treatment will be shown. Unfavorable surgical conditions (e.g. site, extent of the tumor) often result in nonresectability or mutilating surgery. Preoperative therapies must try to achieve a maximum tumor shrinkage aiming at attaining resectability and preservation of organ function and life. The exact evaluation of the response to preoperative therapy is important since the degree of the response correlates directly with outcome. Unfavorable response to preoperative therapy means unfavorable prognosis and requires further, more aggressive therapy. A very important parameter in this evaluation is the "histologic response", measured by the degree of tumor devitalization at the time of definitive surgery. However, even in cases with complete clinical and histological remission, complete resection of the tumor after preoperative treatment is essential. Despite good response to preoperative treatment followed by complete resection, therapy must be sufficiently continued after surgery. Preoperative therapy should achieve maximum tumor control, that means total necrosis of all tumor cells to make a complete resection of the devitalized tumor easier and to get the possibility to preserve organ function.