Feasibility of a Lifestyle Intervention for Women With Triple-negative Breast Cancer Under Neoadjuvant Immunotherapy

This study examines a nutritional concept developed specifically for this study with regard to the implementation of a switch to a high-fibre diet in patients with TNBC undergoing neoadjuvant immunotherapy and chemotherapy. This nutritional concept is embedded in an online, integrative oncology group training programme with mind-body medicine elements to support the change in diet and its tolerability. This intervention is compared with a control group that receives standard care, i.e. a flyer and an educational training video with nutritional recommendations based on the guidelines of the German Nutrition Society (DGE).

The following criteria have been established to determine the feasibility of these two target levels:

* Recruitment * Consent to participate and randomisation * Dropout rate * Implementation of the intervention (dietary change and acceptance/effect of mind-body elements) * Completeness of data collected for at least 80% of patients who complete the study

If the study proves feasible and demonstrates the viability of this integrative medical approach in women with TNBC undergoing neoadjuvant immunotherapy, a confirmatory intervention study with a larger sample size is planned. This study aims to contribute to expanding the current knowledge base and improving existing treatment options. The follow-up study aims to investigate the effects of the nutritional concept and the group training programme on the pCR of TNBC. It will analyse whether the nutritional concept and the group training programme enhance the response to immunotherapy and improve its tolerability in the study participants. The findings from this study will therefore be incorporated into the follow-up study, which will investigate the potential for an improved immune response to therapy and, at the same time, identify possible positive effects of the nutritional intervention on the side effect profile of immunotherapy. Furthermore, the design of the nutritional concept and/or the group training programme could be adapted for the follow-up study if the results are appropriate. The findings from both studies will then be transferred to clinical care, thereby optimising the current treatment options for TNBC patients and increasing their chances of recovery in the long term.

• Course of therapy (pCR) [Срок оценки: 6 months after baseline]
• Toxicity (CTCAE 6.0) including adverse events (AEs) [Срок оценки: 6 months after baseline]
• Fatty acid profile (stool sample analysis) [Срок оценки: baseline and 6 months after baseline]
• α-diversity and β-diversity of the microbiome (stool sample analysis) [Срок оценки: baseline and 6 months after baseline]
• Body weight [Срок оценки: baseline, 1 to 3 weeks after baseline (start of the chemotherapy), 3 months after baseline, 6 months after baseline]
• Self-reported quality of life (FACT-B = Functional Assessment of Cancer Therapy - Breast) [Срок оценки: baseline, 1 to 3 weeks after baseline (start of the chemotherapy), 3 months after baseline, 6 months after baseline]
• Self-reported fatigue (FACIT fatigue = Functional Assessment of Chronic Illness Therapy Fatgigue) [Срок оценки: baseline, 1 to 3 weeks after baseline (start of the chemotherapy), 3 months after baseline, 6 months after baseline]
• Self-reported fiber intake (dietary records) [Срок оценки: baseline, 1 to 3 weeks after baseline (start of the chemotherapy), 3 months after baseline, 6 months after baseline]
• Self-reported tolerance of increased fiber intake (IBS-SSS = irritable bowel syndrome severity scoring system) [Срок оценки: baseline, 1 to 3 weeks after baseline (start of the chemotherapy), 3 months after baseline, 6 months after baseline]
• Adverse Events and Serious Adverse Events [Срок оценки: baseline, 1 to 3 weeks after baseline (start of the chemotherapy), 3 months after baseline, 6 months after baseline]