Hypothesis: Fasting before (48h) and one day after chemotherapy may protect normal cells from the adverse effects of chemotherapy. Design: Within a randomized controlled pilot trial 30 female patients with gynecological cancer (ovarian and breast cancer)and 4-6 scheduled chemotherapies will be randomized to fast 60-72 hours during the first half of chemotherapies or during the second half of chemotherapies and to proceed normocaloric food intake during the other cycles.Sequence of fasting and normocaloric food intake will be randomized. Assessments of adverse effects, quality of life and laboratory values take place 24 and 7 days after each chemotherapy. Statistical analyses compare summarized differences of fasted and non-fasted chemotherapy cycles.

Evidence from experimental animals provides strong support for the concept that caloric restriction (CR) increases resistance to multiple forms of stress. CR decreases plasma levels of growth factors, e.g. insulin-like growth factor-I (IGF-I), thereby diverting energy from growth to maintenance. Accordingly, the currently available information suggests that short-term fasting protects normal cells against the perils of (high dose) chemotherapy. In contrast, cancer cells are not (or less) protected as a result of their self-sufficiency in growth signals. This phenomenon is termed Differential Stress Resistance (DSR). DSR may reduce the severity of adverse effects caused by chemotherapy, without interfering with its anti-tumoral effects. A first case series of 10 cancer patients, suggested that short-term fasting may also protect against the side effects of chemotherapy in humans. This study aims to further evaluate the impact of short-term fasting on tolerance to chemotherapy in humans.Within a randomized controlled pilot trial 30 female patients with gynecological cancer disease (ovarian and breast cancer)in all stages and 4-6 scheduled chemotherapies will be randomized to fast 60-72 hours during half of chemotherapies and to have normocaloric food intake during the other chemotherapies. Fasting is defined as caloric restriction to below 400kcal energy intake/day with free intake of water and tea. Sequences of fasting and normocaloric food intake will be randomized. Assessments of adverse effects, quality of life, fatigue and laboratory values will take place 24 and 7 days after each chemotherapy. Statistical analyses will compare the summarized differences of fasted and non-fasted chemotherapy cycles, that means a total of max. 60-90 chemotherapies with accompanying fasting will be compared to 60-90 non-fasted chemotherapies.

Inclusion Criteria:

• Ovarian cancer or breast cancer
• scheduled chemotherapy
• First diagnosis or 1.recurrence

mono

Exclusion Criteria:

• cachexia (BMI < 21kg/m2)
• eating disorder
• renal failure (Crea >2mg/dl)
• enterostoma
• short bowel syndrome
• not assigned to other studies