Cancers of the upper aerodigestive tract account for around 4% of all malignant tumours
worldwide. Colon and liver cancer are the most common digestive cancers. The epidemiology
of liver cancer is changing, and the number of deaths from liver cancer has increased by
25% worldwide (Huang 2022). In France, around 19,000 cancers of the upper aerodigestive
tract and 88,000 new cases of digestive cancer are diagnosed each year (colon cancer
remains the most common) (Globocan 2020). Patients with these two types of cancer are at
particularly high risk of undernutrition (Pressoir 2010; Gyan 2018).
In cancer patients, changes in diet may result from constraints linked to the cancer or
possible after-effects, but also from personal choices (for example, adopting a healthier
diet). Cancer and its treatment lead to changes such as increased nutritional
requirements and hypercatabolism, or sensory changes (taste and smell), reducing pleasure
and food intake. These problems will impair quality of life and intensify undernutrition,
a major problem in the management of the disease since it increases the risk of
complications, therapeutic failure and mortality. It is estimated that 10-20% of deaths
in cancer patients are attributable to the consequences of undernutrition rather than to
the disease itself (Pressoir 2010). In the VICAN study, 41% of patients changed their
diet after diagnosis: 29% because of changes in taste and 82% to have a healthier diet
(INCa 2014). These changes were associated with the treatment received, the presence of
sequelae and anxiety.
Taste and smell disorders are common in different types of cancer (any solid or
haematological type) and treatments (chemotherapy, radiotherapy and surgery) (De Conno
1989; Heckel 2015; Spotten 2017; van Oort 2018). The mechanisms involved in sensory
changes are not fully understood, especially in cancer, and with different types and
treatments (Murtaza 2017). Several hypotheses have been proposed: altered expression of
enzymes of the oral sphere, altered expression of sensory receptors (Neiers 2021), saliva
composition and function (Zhu 2021), and impact of the oral microbiota (Schwartz 2021a,
Licandro 2023).
The early identification of undesirable effects linked to nutrition, and the early or
anticipated diagnosis of undernutrition are important issues in the management of cancer
patients. The pleasure (or displeasure) produced by food guides desire and eating
behaviour. The mechanisms involved are linked to hedonic sensations: conditioned satiety,
specific sensory satiety, negative alliesthesia and the reward system (hedonic system).
The latter is influenced by the environment and can be consciously controlled, with
several dimensions: liking (the patient likes or dislikes a given food) and wanting
(evaluates the desire to consume a given food at a given moment). All these parameters,
together with sensory and dietary learning throughout life (habits, beliefs and
constraints), influence food preferences and therefore eating behaviour. Individual
sensitivities and the personal history of the disease (treatment and care pathway,
sequelae, presence of co-morbidities, etc.) must therefore be taken into account when
setting up preventive actions for cancer patients. It seems important to explore these
factors, the experience of patients and the consequences for eating behaviour in daily
life, in order to improve support and communication with healthcare professionals, as
well as prevention and early detection of undernutrition. It would be interesting to
conduct more in-depth studies on nutritional status, quality of life and changes in taste
and smell, which in most studies have been considered separately.