Childhood cancer is a serious and life-changing disease that affects thousands of children every year worldwide. In addition to the disease itself, cancer treatments such as chemotherapy often cause difficult side effects. Among these, changes in taste and smell are very common but still poorly understood in children. These sensory changes can make food taste unpleasant or smell different, leading children to eat less, avoid certain foods, or develop strong food aversions. As a result, many children with cancer experience weight loss, poor nutrition, and reduced quality of life, which can also affect how well they tolerate treatment.

Research suggests that between 40% and 60% of children with cancer struggle to maintain good nutritional status during treatment. Taste and smell alterations play a major role in these difficulties. Children may experience nausea triggered by food smells, changes in food texture perception, or a loss of pleasure in eating. Parents often report feeling powerless and lacking clear guidance on how to help their child cope with these problems.

While taste and smell disturbances have been widely studied in adults with cancer, much less is known about how children experience these changes and, importantly, how they and their families adapt to them. Parents play a key role in supporting their child's eating habits, but their perspectives may differ from the child's own experiences.

This study aims to better understand how children undergoing chemotherapy and their parents perceive changes in taste, smell, and food texture, and how these changes affect eating behavior, emotions, and social life. Using individual semi-structured interviews, the study will explore the coping strategies used by children and parents to manage these sensory changes, both at home and in the hospital setting.

By giving children and parents a voice, this research seeks to identify practical, real-life strategies that families find helpful. The results will contribute to improving nutritional support and guidance for children with cancer, with the ultimate goal of enhancing their well-being, quality of life, and treatment outcomes.

Childhood cancer represents a major public health concern and remains one of the leading causes of disease-related mortality in children. Advances in treatment have improved survival, but chemotherapy is frequently associated with adverse effects that significantly impact nutritional status and quality of life. Malnutrition affects approximately 40-60% of pediatric oncology patients and is associated with poorer treatment tolerance, increased risk of infection, immune dysfunction, and reduced survival.

Among treatment-related toxicities, alterations in taste (dysgeusia) and smell (dysosmia) are increasingly recognized as key contributors to feeding difficulties. Chemotherapy targets rapidly dividing cells, including gustatory and olfactory receptor cells, which may explain the high prevalence of sensory disturbances. Taste and smell play a central role in appetite regulation and food enjoyment; their disruption can lead to reduced intake, food aversions, and changes in texture preferences. Although these effects are well documented in adults, pediatric data remain limited and heterogeneous, particularly regarding children's subjective experiences and coping mechanisms.

Recent studies suggest that up to 60% of children receiving chemotherapy experience taste and/or smell alterations perceived as highly distressing. Adolescents frequently report that food "does not taste good" and that food-related smells trigger nausea. Parents often identify sensory changes as the main cause of feeding problems, yet discrepancies may exist between parental perceptions and children's lived experiences. Furthermore, little is known about how food texture perception evolves in children with cancer, despite evidence that tactile oral sensitivity can strongly influence food selectivity.

This study is designed as a prospective, monocentric, non-interventional observational study (RIPH3), using a qualitative methodology based on individual semi-structured interviews. Participants will include children aged 6-17 years undergoing chemotherapy for a malignant hematological or solid tumor, and one of their parents or legal guardians. Interviews will be conducted separately with children and parents to ensure independent data collection and minimize mutual influence. Fifteen children and one of their parent will be included.

The primary objective is to identify and describe the coping strategies used by children and parents to manage taste, smell, and texture alterations and associated changes in eating behavior during chemotherapy. Secondary objectives include characterizing the nature, frequency, intensity, and duration of reported sensory alterations; exploring their emotional and social impact; examining the influence of cancer type, treatment stage, and eating context (hospital versus home); and assessing concordance and discrepancies between children's and parents' experiences and descriptions.

Data analysis will follow a rigorous qualitative approach, including thematic coding, verification of code saturation, and cross-checking by a second researcher to ensure analytical reliability. Reflexivity will be supported through the use of a field journal documenting the researcher's observations and potential biases.

This study will be among the first qualitative investigations in France to focus specifically on chemo-sensory alterations in pediatric oncology from both the child's and the parent's perspectives. By identifying effective, family-driven coping strategies, the findings aim to inform future nutritional guidance, supportive care interventions, and clinical recommendations, ultimately improving nutritional outcomes and quality of life for children undergoing cancer treatment.

Inclusion Criteria:

Children:

• Aged 6 to 17 years old on the day consent is obtained.
• Diagnosed with a malignant hematological or oncological tumor.
• Possessing sufficient verbal ability to participate in the interview planned for the study.
• Having started chemotherapy treatment at least 2 months prior.
• Agreeing to participate in the study.
• Able to understand, read, and write French.
• Affiliated with a social security system.

Parents:

• Be the parent or legal guardian of a child aged 6 to 17 inclusive, with cancer and undergoing chemotherapy.
• Dated and signed informed consent.
• Able to understand, read, and write French.

Exclusion Criteria:

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History of cancer

Any cognitive impairment or condition that may limit the use of numerical scales and quality of life questionnaires, including but not limited to:

Children with neurodevelopmental disorders such as autism or Down syndrome These children may have specific cognitive or communication characteristics that require specialized interview techniques. Their inclusion could complicate data comparability and introduce confounding factors. This exclusion ensures data quality and consistency, while respecting the well-being of participants.

Patients for whom other types of cancer treatment are planned during the study period (e.g., radiation therapy) Patients in relapse Presence of a pre-existing pediatric eating disorder or pre-existing food selectivity