[Etiology, diagnostic and therapeutic management of taste disorders]

Taste alterations during neo/adjuvant chemotherapy and subsequent follow-up in breast cancer patients: a prospective single-center clinical study

PURPOSE

Dysgeusia and taste alterations (TAs) are side effects of cytotoxic chemotherapy and affect patients' quality of life; however, the prevalence, types, and duration of TAs and their potential relationship with other clinical disturbances are not well-described. Our primary aim was to prospectively evaluate the characteristics of TAs in early breast cancer (EBC) patients during (neo)adjuvant chemotherapy and up to 1 year after its completion.

METHODS

From April 2014 to June 2018, 182 EBC patients entered the study and received (neo)adjuvant chemotherapy, mostly with taxane and anthracycline-containing regimens (65% of cases). A dietitian performed TAs assessment through the Common Terminology Criteria for Adverse Event v4.0 (CTCAE) and the Chemotherapy-induced Taste Alteration Scale (CiTAS) questionnaire during chemotherapy and follow-up according to defined time points: at baseline (T0, before starting chemotherapy); at the first follow-up visit, (T1, 2 months after starting chemotherapy); at the final follow-up visit (T2, 1 week after completing chemotherapy); after that, every 3 months up to 12 months.

RESULTS

Dysgeusia was reported by 69.8% of patients at T1 and declined subsequently; salty flavor distortion was the most frequently reported TA (51.6% of cases). CiTAS was significantly different between T0 and T2 (p < 0.001). Dysgeusia occurred more frequently in patients reporting nausea, mucositis, diarrhea, and appetite modification.

CONCLUSIONS

TAs are common but transient during chemotherapy and occurred frequently with other distressing gastrointestinal side effects. The assessment of these side effects is crucial in managing EBC patients during (neo)adjuvant chemotherapy.

Modifications of taste sensitivity in cancer patients: a method for the evaluations of dysgeusia

PURPOSE

Taste changes due to chemotherapy may contribute to the high prevalence of malnutrition in cancer patients. It is believed that 50-70% of patients with cancer suffer from taste disorders. The aim of the present study was to analyze the taste alterations in patient population compared with that in controls, also in relation to gender. In this way, it could open to a new approach for a personalized diet to prevent and/or reduce taste alterations and malnutrition in cancer patients.

METHODS

Forty-five cancer patients undergoing chemotherapy were compared with healthy controls (n = 32). Taste function test was used to determine taste sensitivity. Different concentrations for each of the four basic tastes (salty, sweet, sour, bitter) and also fat and water tastes were evaluated.

RESULTS

A significant difference in taste sensitivity between patients and control group was found, in line with previous similar studies. As in the control group, taste perception in patients was better in females than in males, suggesting interaction effect between group and gender.

CONCLUSIONS

Coping strategies regarding subjective taste impairment should be provided since alterations in taste sensitivity influence food preferences and appetite. Clinicians could thus have the potential to underpin changes in dietary intake and consequently in nutritional status; understanding the extent of the contribution of each taste would help in the development of effective interventions in future. Consequently, patients can adopt appropriate appetizing strategies and, based on that, change their feeding habits.

Influence of cancer and acute inflammatory disease on taste perception: a clinical pilot study

Purpose

Cancer patients are at high risk of malnutrition and tumor cachexia further increasing morbidity and mortality. Reasons for cachexia are not clear yet, but inflammatory processes as well as the occurrence of taste disorders reducing nutrient uptake are discussed to play key roles. The purpose of this study was to gain insight into causative factors of taste disturbance in cancer patients. Does the cancer itself, inflammatory processes or cancer therapy influence taste disorders?

Methods

To capture an underlying taste disorder patients with cancer (n = 42), acutely hospitalized inflammatory disease patients (n = 57) and healthy controls (n = 39) were examined. To assess the influence of chemotherapy, patients with and without chemotherapy were compared. Taste tests were performed according to DIN ISO 3972:2011. Inflammation was recorded using laboratory parameters. Statistical evaluation was conducted using the Software R.

Results

Cancer patients showed significantly increased taste thresholds for sweet, salty, and umami compared to healthy controls. There were no significant differences in taste detection and recognition between patients with former, current, or without chemotherapeutical treatment. Patients with an acute inflammatory disease showed an increased taste threshold for umami compared to healthy controls.

Conclusions

It could be shown that cancer patients suffer from taste disorders irrespective of an existing chemotherapeutical treatment. Cancer-related inflammation appears to have a greater impact on taste perception than an acute inflammatory process. Therefore, an adapted dietary adjustment should be carried out at an early stage for cancer patients in order to avoid nutritional disorders caused by a taste disorder.

Gustatory dysfunction

Tastes in humans provide a vital tool for screening soluble chemicals for food evaluation, selection, and avoidance of potentially toxic substances. Taste or gustatory dysfunctions are implicated in loss of appetite, unintended weight loss, malnutrition, and reduced quality of life. Dental practitioners are often the first clinicians to be presented with complaints about taste dysfunction. This brief review provides a summary of the common causes of taste disorders, problems associated with assessing taste function in a clinical setting and management options available to the dental practitioner.

Influence of taste disorders on dietary behaviors in cancer patients under chemotherapy

Objectives

To determine the relationship between energy and nutrient consumption with chemosensory changes in cancer patients under chemotherapy.

Methods

We carried out a cross-sectional study, enrolling 60 subjects. Cases were defined as patients with cancer diagnosis after their second chemotherapy cycle (n = 30), and controls were subjects without cancer (n = 30). Subjective changes of taste during treatment were assessed. Food consumption habits were obtained with a food frequency questionnaire validated for Mexican population. Five different concentrations of three basic flavors --sweet (sucrose), bitter (urea), and a novel basic taste, umami (sodium glutamate)-- were used to measure detection thresholds and recognition thresholds (RT). We determine differences between energy and nutrient consumption in cases and controls and their association with taste DT and RT.

Results

No demographic differences were found between groups. Cases showed higher sweet DT (6.4 vs. 4.4 μmol/ml; p = 0.03) and a higher bitter RT (100 vs. 95 μmol/ml; p = 0.04) than controls. Cases with sweet DT above the median showed significant lower daily energy (2,043 vs.1,586 kcal; p = 0.02), proteins (81.4 vs. 54 g/day; p = 0.01), carbohydrates (246 vs.192 g/day; p = 0.05), and zinc consumption (19 vs.11 mg/day; p = 0.01) compared to cases without sweet DT alteration. Cases with sweet DT and RT above median were associated with lower completion of energy requirements and consequent weight loss. There was no association between flavors DT or RT and nutrient ingestion in the control group.

Conclusion

Changes of sweet DT and bitter RT in cancer patients under chemotherapy treatment were associated with lower energy and nutrient ingestion. Taste detection and recognition thresholds disorders could be important factors in malnutrition development on patients with cancer under chemotherapy treatment.

Confocal microscopy of the peripheral gustatory system: comparison between healthy subjects and patients suffering from taste disorders during radiochemotherapy

OBJECTIVES

Laser-scanning microscopy (LSM) was used to compare taste buds and epithelia of fungiform papillae of healthy subjects with those of patients suffering from taste disorders during/after radiochemotherapy (RCT). Aim of the study was to investigate effects responsible for taste loss at a microscopic level.

STUDY DESIGN

Prospective study.

METHODS

Data from 12 healthy subjects (mean age 52.4, SD 9.5 years) were compared with those of 12 patients (mean age 54.7, SD 8.5 years) with head and neck cancer suffering from taste disorders during RCT. Four parameters from LSM were selected for analysis: 1) distance between the pore of the taste buds of fungiform papillae and the crest of the papillary vessels; 2) epithelial cells of each taste bud at 34 mum; 3), cell density, and 4) area of the taste pore at 4 mum. These data were correlated to measures of gustatory sensitivity obtained with both the validated "taste strips" test kit and electrogustometry.

RESULTS

Patients complaining from taste disorders during RCT exhibited a significant decrease of taste function assessed with both natural and electric stimuli. In these patients, we found thicker epithelia and smaller areas of the taste pores compared with healthy subjects. In 30% of those patients, no taste pores were detectable; in deeper sections, however, normal taste buds were present.

CONCLUSIONS

In conclusion, in RCT patients with taste disorders, LSM indicates changes of epithelia of fungiform papilla but no changes of the taste bud structure. Damage of the chorda tympani nerve by scattered rays, direct or indirect mucotoxic effects of chemotherapeutic agents, and covering of taste pores by epithelial cells are likely reasons for taste loss during RCT.