A longitudinal evaluation of smell and taste function in children with cancer during and after treatment with chemotherapy

Smell and taste changes are bothersome treatment symptoms interfering with food intake. It remains unclear how and when children with cancer experience such changes during chemotherapy, and if the symptoms resolve after treatment. In this longitudinal study, we measured smell and taste function of 94 childhood cancer patients treated for hematological, solid, or brain malignancies. Smell and taste function were assessed using commercial Sniffin' Sticks and Taste Strips, respectively. For both tests, normative values were used to identify the presence of smell and taste abnormalities. Self-reported chemosensory and appetite changes were assessed using a questionnaire. Measurements were taken approximately 6 weeks (T0), 3 months (T1), 6 months after starting chemotherapy (T2), and 3 months after termination of chemotherapy or maintenance phase for children with acute lymphoblastic leukemia (ALL) (T3). We found that smell and taste scores did not change during active treatment (T0-2). However, approximately 20% of the patients suffered from decreased taste function according to normative values, particularly children with lymphoma or solid tumors. Changes in smell were predominantly characterized as increased rather than decreased. Self-reported changes were much more common than objectively measured, with smell changes ranging from 26 to 53% and taste changes up to 80% during treatment. After active treatment, odor threshold scores decreased in children with ALL during maintenance phase, whereas total taste scores increased in all children at T3. In summary, objectively measured smell and taste function remained stable during active treatment, while at the individual level a fairly large number of children suffered from chemosensory distortions which comprised either increased or decreased sensitivity. Individual dietary advice and coping strategies are warranted to prevent detrimental effects on food intake in children with cancer.