Taste alterations in breast cancer patients undergoing chemotherapy: an observational study

Taste alterations are a common adverse effect of chemotherapy and may substantially impair quality of life, social interactions, and dietary habits. Reported incidence rates vary widely, partly due to the heterogeneity of assessment methods. This study aimed to investigate chemotherapy-induced taste alterations in patients with breast cancer using both objective (taste strips) and subjective (questionnaire-based) measures.

This was a prospective study conducted between July 2023 and June 2025 at the Candiolo Cancer Institute FPO-IRCCS, in Torino (Italy). Sociodemographic, clinical, anthropometric variables, and dietary habits were collected. Taste alterations were evaluated using both subjective and objective assessment tools (taste strips).

A total of 94 female patients were enrolled. Of these, 70 patients had completed chemotherapy and taste evaluation and were included in the statistical analyses. According to subjective assessment, all taste modalities were significantly altered from pre- to post-chemotherapy evaluation, whereas one third of patients exhibited taste impairment when assessed using taste strips. The two methods showed limited agreement. In multiple regression models adjusted for age, smoking status, and pack-years, higher education level was inversely associated with subjective deterioration in sour (β = -0.49; 95% CI -0.82, -0.16; p = 0.006) and bitter taste perception (β = -0.47; 95% CI -0.79, -0.13; p = 0.006). Moreover, carbohydrate intake was inversely associated with worsening of overall taste perception (β = -1.96; 95% CI -3.72, -0.20; p = 0.035), as well as sour (β = -2.05; 95% CI -4.01, -0.09; p = 0.044) and salty taste perception (β = -1.92; 95% CI -3.76, -0.04; p = 0.046), based on subjective assessment.

Taste alterations affect a substantial proportion of patients with breast cancer undergoing chemotherapy. The low agreement observed between subjective and objective measures suggests that these methods may assess distinct aspects of taste dysfunction and should be interpreted accordingly.