Nutritional status is a major issue in the management of cancer patients. Forty to 60% of patients are undernourished at diagnosis. This undernutrition has a direct impact on patients' health and quality of life, with a reduction in survival associated with an increase in the risk of toxicity from anti-cancer treatments (chemotherapy, radiotherapy, surgery), the risk of infection and the risk of hospitalization. Thus, it is estimated that 10-20% of cancer patients die from the consequences of their undernutrition rather than from the tumor itself (Muscaritoli et al. 2021).

It is therefore recommended to systematically implement a multimodal nutritional intervention in cancer patients (recommendations of the learned societies ESPEN, ESMO and ASCO), combining nutritional support (oral and/or enteral and/or parenteral) with physical exercise (Muscaritoli et al. 2021). However, despite the systematic provision of dietary management, the effectiveness of nutritional interventions varies from patient to patient in terms of nutritional status, quality of life and overall survival (Cintoni et al. 2023).

Among the factors impacting patient compliance with dietary measures and their efficacy, sensory alterations occurring under chemotherapy potentially have a major impact (Drareni et al., 2019).

Indeed, the vast majority of patients describe an alteration in tastes and smells after starting chemotherapy treatment. However, few studies have focused on the specific parameters associated with these alterations. The aim of this study is to prospectively assess changes in sensory perceptions and eating habits in patients undergoing chemotherapy for digestive cancer at the start of treatment and after the first cycle of chemotherapy, and to correlate these alterations with patients' nutritional profile and clinical course.

Inclusion Criteria:

• Able to complete the proposed questionnaires
• Patients over 18 years of age
• Non-opposed patients
• Digestive cancers starting chemotherapy and/or immunotherapy
• Able to eat by mouth

Exclusion Criteria:

• Concomitant treatment for a non-digestive cancer (excluding basal/spinocellular carcinoma and chronic haemopathy)
• Previous ENT surgery (face/neck)
• Exclusive enteral feeding (nasogastric tube, gastrostomy) or parenteral nutrition
• Previous chemotherapy/immunotherapy < 5 years
• Individuals deprived of liberty by a judicial or administrative decision

Patients with malignant digestive tumors receiving active chemotherapy