Smell and Taste Alterations in Patients Receiving Curative or Palliative Chemotherapy—The CONKO 021—ChemTox Trial.

Simple Summary: Taste and smell alterations (TSAs) are a distressing yet underdiagnosed side effect in cancer patients undergoing chemotherapy. However, long-term investigations using both questionnaires and chemosensory tests are scarce. We examined the prevalence of quantitative and qualitative TSAs, as well as their connection with clinical characteristics such as age, sex, anorexia, and neuropathy. We also compared patients receiving perpetual or temporary chemotherapy. All patients were examined up to five times within 12 to 24 months, commencing before the beginning of chemotherapy. We found TSAs in approximately 4 out of 5 patients during chemotherapy. The highest prevalence was documented among patients above 60 years of age as well as among those reporting anorexia or presenting signs of neuropathy. Post-therapy, taste and smell function recovered; however, scores did not reach baseline levels within 6 to 12 months. Future investigations will assess potential interventions to prevent or reduce TSAs. Previous data regarding chemotherapy-induced olfactory and gustatory dysfunction (CIOGD) are heterogeneous due to inconsistent study designs and small numbers of patients. To provide consistent, reliable data, we conducted a cohort study using standardized testing. Patients diagnosed with lymphoma, leukemia, or gastrointestinal malignancies were examined up to five times (T1 to T5), beginning prior to chemotherapy. We examined patients receiving temporary treatment up to 12 months post-therapy. Clinical assessment included extensive questionnaires, psychophysical tests of olfactory and gustatory function, and measurement of peripheral neuropathy. Statistical analysis included non-parametric tests to evaluate the longitudinal development of CIOGD. Our data (n = 108) showed a significant decline in olfactory and gustatory testing during chemotherapy (p-values < 0.001). CIOGD appeared stronger among patients above 60 years, while sex did not matter significantly. However, we identified distinct associations between CIOGD and reported anorexia as well as with higher neuropathy scores. Self-assessment appeared less sensitive to chemosensory dysfunction than psychophysical testing. Post-therapy, olfactory and gustatory function regenerated, though baseline levels were not attained within 6 to 12 months. In conclusion, our data highlight the wide prevalence and slow recovery of CIOGD. Understanding CIOGD as a potential neurotoxic effect may disclose new therapeutic prospects. [ABSTRACT FROM AUTHOR]