Irradiation impairment of umami taste in patients with head and neck cancer

Taste changes during radiotherapy for head and neck cancer

INTRODUCTION

Taste changes (dysgeusia) during radiotherapy for head and neck cancer are associated with malnutrition, tube feeding and reduced toleration of treatment.

METHOD

The MD Anderson symptom inventory - head and neck (MDASI-HN) questionnaire was completed by patients in a single department receiving radical radiotherapy or chemo-radiotherapy for head and neck cancer during weeks 1 and 4 of radiotherapy. Participants who developed dysgeusia in week 4 completed supplementary questions exploring what foods they could taste and how they managed taste changes.

RESULTS

At week 4, 97% of 61 participants reported taste changes, 77% reporting moderate or severe changes. 30% of participants reported taste changes during week 1. Patients with oropharyngeal, oral cavity and parotid gland tumours were most likely to develop dysgeusia. Females were more likely than males to report taste changes. A soft, semi-liquid diet was reportedly easier to tolerate as the more food was chewed the worse the taste became.

CONCLUSIONS

Patients having radiotherapy for all head and neck cancers should be warned of the very high risk of developing taste changes and the time scale for this. Patients with taste changes should be advised a softer diet requiring less chewing will be better tolerated. The finding that females are more at risk than males of dysgeusia needs further investigation.

IMPLICATIONS FOR PRACTICE

Patients with head and neck cancer should expect taste changes from the start of radiotherapy. Patients with dysgeusia should be advised that soft, semi-liquid foods that require less chewing before swallowing are easier to tolerate and that taste changes day-to-day.

The role of saliva in taste dysfunction among cancer patients: Mechanisms and potential treatment

Two of the highest prevalent symptoms reported by cancer patients are taste dysfunction (17.6-93%) and dry mouth/xerostomia (40.4-93%). While it has been hypothesized that reduced saliva may impair taste function, few studies investigate the co-occurrence of taste and dry mouth symptoms in cancer patients. This review provides a summary of the physiological relationship between saliva and taste, focusing on taste transduction mechanism, regulation of the taste sensitivity, and protection of taste receptor cells, including the impact of cancer treatments and malignancy on saliva function, salivary components, and the mechanisms in which it can negatively impact the taste function. Here, the authors present a scoping review of the recent literature reporting on the association between taste dysfunction and dry mouth in cancer patients, including reports of non-pharmaceutical liposomal agents or drugs taken to improve dry mouth symptoms that also assess taste dysfunction. Considering the complexities of cancer and cancer treatment, understanding the physiological relationship between saliva and taste function may provide important insight into identifying treatments for alleviating taste dysfunction and dry mouth symptoms. There are substantial research gaps given the limited studies assessing the co-occurrence of taste loss and dry mouth and inconsistencies in the assessment of these symptoms. Clinical studies examining taste dysfunction will provide a foundational groundwork that will help understand the relationship between taste and saliva. Considering the increased rates in survivorship and the significant negative impact of taste dysfunction on quality of life, more research is needed to reduce the suffering of cancer patients.

Molecular and Neural Mechanism of Dysphagia Due to Cancer

Cancer is one of the most common causes of death worldwide. Along with the advances in diagnostic technology achieved through industry–academia partnerships, the survival rate of cancer patients has improved dramatically through treatments that include surgery, radiation therapy, and pharmacotherapy. This has increased the population of cancer “survivors” and made cancer survivorship an important part of life for patients. The senses of taste and smell during swallowing and cachexia play important roles in dysphagia associated with nutritional disorders in cancer patients. Cancerous lesions in the brain can cause dysphagia. Taste and smell disorders that contribute to swallowing can worsen or develop because of pharmacotherapy or radiation therapy; metabolic or central nervous system damage due to cachexia, sarcopenia, or inflammation can also cause dysphagia. As the causes of eating disorders in cancer patients are complex and involve multiple factors, cancer patients require a multifaceted and long-term approach by the medical care team.

Longitudinal comparisons of a whole-mouth taste test to clinician-rated and patient-reported outcomes of dysgeusia postradiotherapy in patients with head and neck cancer and associations with oral intake

BACKGROUND

After head and neck cancer (HNC) treatment, dysgeusia may be a barrier to oral intake. In this exploratory study, we prospectively examined taste perception, clinician-rated (CRO) and patient-reported (PRO) taste changes and their effect on oral intake postradiotherapy.

METHODS

Twenty-eight patients were assessed at baseline, treatment weeks 2 and 4, and 1, 3, and 6 months post-treatment using a whole-mouth taste test and associated CRO and subjective PRO measures.

RESULTS

Greater taste impairment was reflected by subjective than by a whole-mouth taste test. The most significant and consistent decline occurred mid-treatment. The Chemotherapy-Induced Taste Alteration Scale (PRO) discomfort subscale correlated significantly with maintaining an oral diet, percent of oral intake, and appetite level from mid-treatment to 6 months post-treatment.

CONCLUSIONS

PRO results indicated ongoing oral intake issues. Whole-mouth taste tests may fail to fully reflect functional taste-loss. Dysgeusia prevention and treatment methods are needed to improve patient outcomes.

Taste dysfunction following radiotherapy to the head and neck: A systematic review

BACKGROUND

An intact sense of taste provides pleasure, supports sustenance and alerts the body to toxins. Head and neck cancer (HNC) patients who receive radiotherapy (RT) are high-risk for developing radiation-induced taste dysfunction. Advances in RT offer opportunities for taste-preserving strategies by reducing dose to the gustatory organs-at-risk.

METHODS

PubMed, Medline and EMBASE were searched for publications reporting on taste, RT and HNC. Randomised trials, cohort studies and cross-sectional studies were included.

RESULTS

31 studies were included in this review. Meta-analysed prevalence of acute taste dysfunction following RT was approximately 96% (95% CI 64 to 100%) by objective measures and 79% (95% CI 65 to 88%) by subjective measures, with the majority of patients showing at least partial recovery. Long-term dysfunction was seen in ~25% of patients. Taste dysfunction was associated with sequalae including weight loss and reduced quality-of-life (QoL). Taste dysfunction was more common when the oral cavity, and specifically the anterior two-thirds of the tongue, was irradiated, suggesting a dose constraint for taste preservation might be feasible. Proton beam therapy and customised bite blocks reduced dose to the gustatory field and subsequent loss of taste.

CONCLUSIONS

Taste dysfunction following RT is common and negatively affects patients' nutritional status and QoL. Decisions about treatment strategies, including choice of RT modality, dose distribution across the gustatory field and the use of adjuncts like bite blocks may be beneficial. However, evidence is limited. There is a pressing need for randomised studies or large prospective cohort studies with sufficient adjustment for confounders.

The effects of zinc on radiation-induced dysgeusia: a systematic review and meta-analysis

PURPOSE

Many head and neck cancer patients who receive radiation therapy experience radiation-induced dysgeusia (RID), which has no standard treatment. The only supplement controlled clinical trials have evaluated for the treatment of RID is zinc. However, the results of these and other studies investigating the use of zinc for RID have been inconsistent. To assess the validity of zinc as a treatment for RID, we conducted a systematic literature search and performed a meta-analysis to determine the extent to which zinc affects RID incidence and the degree to which ongoing RID responds to zinc.

METHODS

We searched the Ovid MEDLINE, Ovid Embase, PubMed, and Cochrane Library databases to identify studies investigating the use of zinc-based therapy for RID in head and neck cancer patients treated with radiation that were published between January 1, 2003, and November 9, 2017. Using American Society of Clinical Oncology criteria, we selected studies with a high level of evidence for inclusion in the meta-analysis.

RESULTS

Of the 32 full-text articles eligible for inclusion, three were included in the final review and meta-analysis. The meta-analysis showed that, compared with placebo, zinc reduces the incidence of RID (risk ratio, 0.72; 95% confidence interval, 0.67-0.92) but does not improve taste acuity more rapidly following radiation therapy (risk ratio, 2.58; 95% confidence interval, 0.97-6.88).

CONCLUSION

Our findings indicate that zinc-based therapy reduces the incidence of RID but has a minimal effect on ongoing RID. Our findings also highlight the need for additional evidence-based research on this topic.

Development and validation of a contouring guideline for the taste bud bearing tongue mucosa

PURPOSE

To introduce a contouring guideline for the taste bud bearing tongue mucosa for head and neck cancer patients receiving radiotherapy.

METHODS AND MATERIALS

CT simulation images of oropharyngeal cancer patients were used to delineate both the whole tongue (extrinsic/intrinsic tongue muscles, floor of mouth) and the taste bud bearing tongue mucosa (method A: adaptation of the whole tongue structure; method B: axial adaptation of a mid-sagittal contour). Volumetric and dosimetric parameters of the whole tongue and the two methods of mucosal delineation, spatial overlap between methods A and B, and inter-observer variability for method B were calculated.

RESULTS

The study cohort was comprised of 70 patients with T1-4 N0-1 tonsillar (83%) and base of tongue (17%) cancers. Most of the comparative parameters between the whole tongue and mucosa (method A) significantly differed (mean, minimum, and maximum dose, V5-V70, D40-D90). The mean dose calculated for the whole tongue deviated on average 3.77 Gy compared to method A. No significant differences were found between methods A and B of the taste bud bearing tongue mucosa structure, and none of the dosimetric parameters differed more than 1.03 Gy on average. The mean Dice similarity coefficient for both mucosal structures was 0.79 ± 0.05, and 0.63 ± 0.12 for the inter-observer analysis of method B.

CONCLUSIONS

We defined two methods for delineating the taste bud bearing mucosa and both are equally satisfactory procedures. Either method is preferable over delineation of the whole tongue as organ at risk for taste impairment.

Taste Function in Adults Undergoing Cancer Radiotherapy or Chemotherapy, and Implications for Nutrition Management: A Systematic Review

BACKGROUND

Taste changes are commonly reported by people with cancer undergoing radio- or chemotherapy. Taste changes may compromise dietary intake and nutritional status.

OBJECTIVE

To understand whether or not taste change is associated with cancer diagnosis or treatment modality in adults.

METHODS

A systematic literature search up to December 31, 2019, was conducted using PubMed, Embase, and PsycInfo (International Prospective Register of Systematic Reviews protocol no. CRD42019134005). Studies in adults with cancer objectively assessing the effect of a cancer diagnosis or chemotherapy and/or radiotherapy treatment on taste function compared with healthy controls or within participant changes were included. Additional outcomes were food liking, appetite, dietary intake, nutritional status, and body composition. Reference lists of relevant articles were searched to identify additional articles. Quality was assessed using the Academy of Nutrition and Dietetics quality criteria checklist.

RESULTS

A total of 24 articles were included, one of which consisted of two studies that reported the effects of radiotherapy and chemotherapy separately. From the total 25 studies reported in 24 published articles, 14 studies examined effects of radiotherapy, and remaining 11 studies examined chemotherapy. There is limited evidence of a cancer diagnosis per se contributing to taste dysfunction. Impaired taste function was reported in almost all radiotherapy studies, occurring as early as Week 3 of treatment and lasting for 3 to 24 months posttreatment. During chemotherapy, impairment of taste function was less consistently reported, occurring as early as the first few days of chemotherapy, and persisting up to 6 months posttreatment. Taxane-based chemotherapy was reported to affect taste function more than other treatments. Several studies reported reduced liking for food, appetite, and dietary intake. Only one study reported nutritional status of participants, finding no association between taste function and nutritional status. No studies examined associations between taste changes and body composition.

CONCLUSIONS

This review highlights the importance of considering treatment modality in practice. Research is required to identify factors contributing to taste alteration and to inform evidence-based interventions.

Development of a Tongue Immobilization Device Using a 3D Printer for Intensity Modulated Radiation Therapy of Nasopharyngeal Cancer Patients

Purpose

This study aimed to reduce radiation doses to the tongue, a patient-specific semi-customized tongue immobilization device (SCTID) was developed using a 3D printer for helical tomotherapy (HT) of nasopharyngeal cancer (NPCa). Dosimetric characteristics and setup stability of the SCTID were compared with those of a standard mouthpiece (SMP).

Materials and Methods

For displacement and robust immobilization of the tongue, the SCTID consists of four parts: upper and lower tooth stoppers, tongue guider, tongue-tip position guide bar, and connectors. With the SCTID and SMP, two sets of planning computed tomography and HT plans were obtained for 10 NPCa patients. Dosimetric and geometric characteristics were compared. Position reproducibility of the tongue with SCTID was evaluated by comparing with planned dose and adaptive accumulated dose of the tongue and base of the tongue based on daily setup mega-voltage computed tomography.

Results

Using the SCTID, the tongue was effectively displaced from the planning target volume compared to the SMP. The median mucosa of the tongue (M-tongue) dose was significantly reduced (20.7 Gy vs. 27.8 Gy). The volumes of the M-tongue receiving a dose of 15 Gy, 30 Gy, and 45 Gy and the volumes of the mucosa of oral cavity and oropharynx (M-OC/OP) receiving a dose of 45 Gy and 60 Gy were significantly lower than using the SMP. No significant differences was observed between the planned dose and the accumulated adaptive dose in any dosimetric characteristics of the tongue and base of tongue.

Conclusion

SCTID can not only reduce the dose to the M-tongue and M-OC/OP dramatically, when compared to SMP, but also provide excellent reproducibility and easy visual verification.

Prospective assessment of gustatory function after radiotherapy for head and neck cancers

BACKGROUND

Taste disorders are major causes of morbidity in patients undergoing head and neck irradiation. We quantitatively assessed the gustatory function of patients with head and neck cancers who underwent radiotherapy using recently developed standardised tools for measuring taste.

METHODS

Twenty patients undergoing head and neck irradiation responded to a specific questionnaire and were assessed by olfactory and gustatory function tests. To assess changes over time, testing was performed before, immediately after, and at 2- and 4-week intervals following the start of radiotherapy. Concurrently, patients were evaluated for xerostomia from radiotherapy.

RESULTS

A decrease in the taste recognition threshold was observed in the second week after the beginning of radiotherapy. The taste detection threshold improved within the 14th-18th week. Most affected patients demonstrated that their gustatory function primarily decreased independent of the olfactory function. Disturbances in taste were exponentially worsened beyond an accumulated dose of 30 Gy and involved all tastants. According to a multivariate analysis, radiation-induced taste impairment was not influenced by the degree of xerostomia. However, there was an association between the dose of irradiation and the severity of taste disturbance.

CONCLUSIONS

In this preliminary study, we found that the taste function was worse 2 weeks after the start of radiotherapy and returned to pretreatment levels within 4.5 months. Taste disturbances were exponentially worse beyond an accumulated dose of 20 Gy. Taste dysfunction after radiotherapy was not influenced by the degree of xerostomia, whereas only the dose of irradiation was associated with the severity of taste dysfunction.

The impact of hematological malignancies and their treatment on oral health-related quality of life as assessed by the OHIP-14: a systematic review

Patients with hematologic cancers often develop acute and chronic oral complications from their disease and its treatment. These problems could change patients' oral health-related quality of life (OHRQoL) negatively. Quality of life (QoL) has become an increasingly important outcome measure in oncology. This systematic literature review evaluates the impact of hematological malignancies and their treatment on OHRQoL as assessed by the Oral Health Impact Profile (OHIP-14) questionnaire. Medline through Pubmed and Web of Science were searched through April 2017. Two randomized controlled trials, one cohort study, one cross-sectional study, and one case-control study were included. Heterogeneity across the included studies did not allow for meta-analysis. OHIP-14 domains that were frequently given the highest scores were functional limitation (67%), physical pain (50%), physical disability (50%), and psychological discomfort (33%). The domains that were frequently given the lowest scores were social handicap (100%), social disability (100%), and psychological disability (67%). Insufficient evidence is available to draw any robust conclusions regarding OHRQoL assessed by the OHIP-14 in individuals with hematological malignancies. However, functional limitations because of problems with oral mucosal tissues, the dentition, or dentures, seem to have a larger negative impact on the OHRQoL than social aspects associated with oral health problems. Well-designed larger studies are required to determine effects of hematological malignancies as well as acute and long-term effects of their treatment on patients' OHRQoL.

Oral examination findings, taste and smell testing during and following head and neck cancer therapy

PURPOSE

Diet and nutrition are critical in health and disease and are highly impacted by the presence and treatment for head and neck cancer (HNC). The purpose of this paper is to present oral examination findings and taste and smell test results in patients during and following HNC.

METHODS

Patients with HNC were evaluated during and following radiation therapy with/without chemotherapy. Oral examination findings including mucositis, saliva, oral hygiene (plaque levels, gingivitis), and taste and smell testing was completed on all subjects. NCI Common Terminology Criteria for Adverse Events (CTCAE) 4.0, and the Scale of Subjective Total Taste Acuity (STTA) were used to provide patient report of symptoms.

RESULTS

Mucositis and pain affected oral diet during therapy and improved in follow-up. Weight loss of 5% during and 12% following treatment was identified. Tobacco use was associated with increased severity of mucositis and increased weight loss. The subjects maintained excellent oral hygiene as reflected in plaque levels and gingivitis. Spicy/pungent perception was the most strongly disliked of testing stimuli. Umami and fat taste perception were reported of highest intensity during HNC treatment and rated as moderate in intensity after treatment. These results suggest improvement in these taste functions over time following treatment. Salt taste was of high intensity and associated with strong dislike in follow-up.

CONCLUSIONS

In HNC patients, oral status and taste change occurs throughout the cancer trajectory and represent potential concerns in cancer survivorship. Taste change (as evaluated by taste testing) occurred in all HNC patients, whereas olfactory changes occurred in 30% of cases. Management of oral changes and symptoms should be considered in all HNC patients in addition to dietary and nutritional guidance in patient care to promote oral intake. Continuing study of taste changes may further define this problem and support dietary and nutritional guidance and product development.

Development of a semi-customized tongue displacement device using a 3D printer for head and neck IMRT

Purpose

To reduce radiation doses to the tongue, a patient-specific semi-customized tongue displacement device (SCTDD) was developed using a 3D printer (3DP) for head and neck (H&N) radiation therapy (RT). Dosimetric characteristics of the SCTDD were compared with those of a standard mouthpiece (SMP).

Materials and methods

The SCTDD consists of three parts: a mouthpiece, connector with an immobilization mask, and tongue displacer, which can displace the tongue to the contralateral side of the planning target volume. Semi-customization was enabled by changing the thickness and length of the SCTDD. The instrument was printed using a 3DP with a biocompatible material. With the SCTDD and SMP, two sets of planning computed tomography (CT) and tomotherapy plans were obtained for seven H&N cancer patients. Dosimetric and geometric characteristics were compared.

Results

Using the SCTDD, the tongue was effectively displaced from the planning target volume without significant tongue volume change compared to the SMP. The median tongue dose was significantly reduced (29.6 Gy vs. 34.3 Gy). The volumes of the tongue receiving a dose of 15 Gy, 30 Gy, 35 Gy, 45 Gy, and 60 Gy were significantly lower than using the SMP.

Conclusion

The SCTDD significantly decreased the radiation dose to the tongue compared to the SMP, which may potentially reduce RT-related tongue toxicity.

Patho-physiological and toxicological aspects of monosodium glutamate

Nowadays, the life-line of urban population has been formed by commercial foods due to industrialization, urbanization, and rapid increase in working class. Commercial foods are time and energy saving foods but it compromising the nutritional value of foods. The term adulteration refers to the deliberate addition of compound which is usually not present in food. These compounds are known as food additives or food adulterant. Monosodium Glutamate (MSG) is one of the most common food additives. Several studies revealed that MSG has toxic effect on fetal development/fetus, children's, adolescent, and adults. Physiological complication associated with MSG toxicity are hypertension, obesity, gastrointestinal tract troubles, and impairment of function of brain, nervous system, reproductive, and endocrine system. The effect of MSG depends upon its dose, route of administration and exposure time. Public awareness may play a major role in controlling the food adulteration by working in collaboration with National testing facilities to scrutinize each commercial food article from time to time. The aim of this review article is to highlight the deleterious impact of MSG on human health.

Radiation-Related Alterations of Taste Function in Patients With Head and Neck Cancer: a Systematic Review

OPINION STATEMENT

Taste sensation is vital for a healthy body as it influences our food intake, acts as a defense mechanism and elicits pleasure. Majority of the head and neck cancer (HNC) patients undergoing radiotherapy suffer from altered taste function and often complain of inability to taste their food, reduced food intake, and weakness. However, there are not many studies conducted to assess this commonly reported side effect. Furthermore, clinical research on radiotherapy-induced taste alterations has proven to be difficult, considering a lack of reliable and validated study tools for assessing objective and subjective outcomes. Developing standardized tools for assessment of taste function and conducting prospective studies in larger population of HNC is the need of the hour. Taste sensation being critically important for sustenance, we need to focus on ways to preserve it. The physical properties of proton particle enable localization of the radiation dose precisely to the tumor and minimizing the exposure of the adjacent healthy tissues. By using Intensity-Modulated Proton Therapy in HNC patients, we anticipate preserving the taste sensation by reducing the dose of radiation to the taste buds.

Relationship between subjective taste alteration and weight loss in head and neck cancer patients treated with radiotherapy: A longitudinal study

PURPOSE

To conduct a dynamic and comprehensive evaluation of subjective taste alteration (STA)and identify the association between STA and weight loss in patients with head and neck cancer (HNC) who were treated with radiotherapy.

METHODS

STA and weight of 114 patients were recorded at baseline, mid-treatment, post-treatment, and one to two months after radiotherapy (follow-up). Generalized estimating equations (GEE) were used to conduct repeated measures analyses of STA and weight loss at four time-points and assess the relationship between them.

RESULTS

The prevalence of STA was 13.2% (baseline), 83.3% (mid-treatment), 92.1% (post-treatment), and 77.9% (follow-up), respectively; the prevalence of ≥10% weight loss increased from 1.8% (mid-treatment) to 44.2% (follow-up). The severity of STA was increasingly poor with radiation therapy and did not return to the baseline level at the follow-up. Meanwhile, the weight of patients did not increase at the follow-up. Among the four subscales of STA (decline in basic taste, general taste alterations, phantogeusia and parageusia, and discomfort), only the discomfort score (β = -2.988; p = 0.005; 95%confidence interval: -5.084-0.891) had a significant effect on weight loss.

CONCLUSIONS

The main finding of this study was that STA, particularly the discomfort symptom associated with dietary intake, as a common and persistent symptom among HNC patients during and after radiotherapy, might promote weight loss in patients, which should be afforded greater attention from medical staff.

Assessing taste and smell alterations in cancer patients undergoing chemotherapy according to treatment

PURPOSE

Taste and smell changes are common side effects in cancer patients undergoing chemotherapy treatments (CT). This can lead to a reduced food enjoyment and an inadequate nutrient intake with a high impact on nutritional status and quality of life. The aim of this study was to evaluate the self-reported chemosensory alterations of patients undergoing chemotherapy according to CT type.

METHODS

An observational study was conducted with 151 patients undergoing CT at Oncology Outpatient Unit from Onkologikoa Foundation. An interviewer-assisted questionnaire was designed to investigate chemosensory changes in patients undergoing CT.

RESULTS

Seventy-six percent patients reported taste disorders and 45% smell changes. Xerostomia is the most frequent symptom reported by patients receiving chemotherapy in our study (63.6%), and it is strongly associated to bad taste in mouth (OR = 5.96; CI = 2.37-14.94; p value = 0.000) and taste loss (OR = 5.96; CI = 2.37-14.94; p value = 0.000). Anthracyclines, paclitaxel, carboplatin, and docetaxel were the CT agents producing the highest taste disturbance rates. Cisplatin and 5-Fluorouracil are the CT resulting in the lowest complaints. Logistic regression revealed statistically significant associations between taste loss and carboplatin and docetaxel (OR = 3.50; CI = 1.12-10.90; p value = 0.031) and cold hypersensitivity and oxaliplatin (OR = 12.14; CI = 4.18-35.25; p value = 0.000). Not only platin-based CT such as carboplatin produced dysgeusia, but also anthracyclines and paclitaxel treatments.

CONCLUSIONS

The better knowledge of taste and smell alterations according to CT type may provide valuable information for the design of new strategies to tackle CT side effects. It is important to take into account taste and smell dysfunctions and other alterations such as xerostomia together.

Decreased radiation doses to tongue with "stick-out" tongue position over neutral tongue position in head and neck cancer patients who refused or could not tolerate an intraoral device (bite-block, tongue blade, or mouthpiece) due to trismus, gag reflex, or discomfort during intensity-modulated radiation therapy

Purpose

To assess changes in oral cavity (OC) shapes and radiation doses to tongue with different tongue positions during intensity-modulated radiation therapy (IMRT) in patients with head and neck squamous cell carcinoma (HNSCC) but who refused or did not tolerate an intraoral device (IOD), such as bite block, tongue blade, or mouthpiece.

Results

Tongue volume outside of OC was 7.1 ± 3.8 cm³ (5.4 ± 2.6% of entire OC and 7.8 ± 3.1% of oral tongue) in IMRT-S. D_mean of OC was 34.9 ± 8.0 Gy and 31.4 ± 8.7 Gy with IMRT-N and IMRT-S, respectively (p < 0.001). OC volume receiving ≥ 36 Gy (V36) was 40.6 ± 16.9% with IMRT-N and 33.0 ± 17.0% with IMRT-S (p < 0.001). D_mean of tongue was 38.1 ± 7.9 Gy and 32.8 ± 8.8 Gy in IMRT-N and IMRT-S, respectively (p < 0.001). V15, V30, and V45 of tongue were significantly lower in IMRT-S (85.3 ± 15.0%, 50.6 ± 16.2%, 24.3 ± 16.0%, respectively) than IMRT-N (94.4 ± 10.6%, 64.7 ± 16.2%, 34.0 ± 18.6%, respectively) (all p < 0.001). Positional offsets of tongue during the course of IMRT-S was –0.1 ± 0.2 cm, 0.01 ± 0.1 cm, and –0.1 ± 0.2 cm (vertical, longitudinal, and lateral, respectively).

Materials and Methods

13 patients with HNSCC underwent CT-simulations both with a neutral tongue position and a stick-out tongue for IMRT planning (IMRT-N and IMRT-S, respectively). Planning objectives were to deliver 70 Gy, 63 Gy, and 56 Gy in 35 fractions to 95% of PTVs. Radiation Therapy Oncology Group (RTOG) recommended dose constraints were applied. Data are presented as mean ± standard deviation and compared using the student t-test.

Conclusions

IMRT-S for patients with HNSCC who refused or could not tolerate an IOD has significant decreased radiation dose to the tongue than IMRT-N, which may potentially reduce RT related toxicity in tongue in selected patients.

Common oral complications of head and neck cancer radiation therapy: mucositis, infections, saliva change, fibrosis, sensory dysfunctions, dental caries, periodontal disease, and osteoradionecrosis

Patients undergoing radiation therapy for the head and neck are susceptible to a significant and often abrupt deterioration in their oral health. The oral morbidities of radiation therapy include but are not limited to an increased susceptibility to dental caries and periodontal disease. They also include profound and often permanent functional and sensory changes involving the oral soft tissue. These changes range from oral mucositis experienced during and soon after treatment, mucosal opportunistic infections, neurosensory disorders, and tissue fibrosis. Many of the oral soft tissue changes following radiation therapy are difficult challenges to the patients and their caregivers and require life-long strategies to alleviate their deleterious effect on basic life functions and on the quality of life. We discuss the presentation, prognosis, and management strategies of the dental structure and oral soft tissue morbidities resulting from the administration of therapeutic radiation in head and neck patient. A case for a collaborative and integrated multidisciplinary approach to the management of these patients is made, with specific recommendation to include knowledgeable and experienced oral health care professionals in the treatment team.

Alteration in Taste Perception in Cancer: Causes and Strategies of Treatment

The sense of taste is responsible for the detection and ingestion of food to cover energetic requirements in health and disease. The change in taste perception might lead to malnutrition that is usually one of the frequent causes of morbidity and mortality in patients with cancer. In this review, we summarize the mechanisms of taste perception and how they are altered in cancer. We also address the question of the implication of inflammation, responsible for the alterations in taste modalities. We highlight the role of radio- and chemotherapy in the modulation of taste physiology. Other several factors like damage to taste progenitor cells and disruption of gut microbiota are also dealt with relation to taste perception in cancer. We further shed light on how to restore taste acuity, by using different preventive methods, dietary modifications and pharmacotherapy in subjects with advanced cancer state.

Effects of chemotherapy on gene expression of lingual taste receptors in patients with head and neck cancer

OBJECTIVES/HYPOTHESIS

We aimed to test the hypothesis that chemotherapy changes the gene expression of taste receptors in the tongue to induce dysgeusia in patients with head and neck cancer.

STUDY DESIGN

Prospective observation study.

METHODS

We enrolled 21 patients who received chemoradiotherapy and five patients who underwent radiotherapy for head and neck cancer. The messenger RNA (mRNA) levels of the taste receptor subunits T1R1, T1R2, T1R3, and T2R5 were measured in lingual mucosa scrapings obtained with a small spatula. The perception thresholds of umami, sweet, and bitter tastes were assessed by the whole mouth gustatory test.

RESULTS

In four patients with severe stomatitis induced by chemoradiotherapy, the mRNA levels of T1R1, T1R2, T1R3, and T2R5 in the lingual mucosa were significantly decreased. However, in 17 patients with mild/moderate stomatitis, the mRNA levels of T1R3 were significantly and transiently decreased, whereas those of T1R1 and T1R2 remained unchanged and those of T2R5 mRNA were significantly and transiently increased after chemotherapy. There was a significant negative correlation between the perception thresholds of umami or sweet tastes and lingual mRNA levels of T1R3 in patients with mild/moderate stomatitis after chemotherapy. Although the perception threshold of bitter taste remained unchanged, lingual mRNA levels of T2R5 were significantly increased in patients who complained of phantogeusia after chemotherapy.

CONCLUSION

Chemotherapy specifically changed the gene expression of T1R3 and T2R5 in head and neck cancer patients with mild/moderate stomatitis, resulting in both dysgeusia of umami and sweet tastes as well as phantogeusia.

LEVEL OF EVIDENCE

4. Laryngoscope, 126:E103-E109, 2016.

Advances in Supportive Care for Late Effects of Head and Neck Cancer

As the population of head and neck cancer survivors increases, it has become increasingly important for health care providers to understand and manage late complications of therapy. Functional deficits can be categorized as general health deficits resulting in frailty or debility, head and neck-specific functional deficits such as swallowing and speech, and musculoskeletal impairment as a result of tumor and treatment. Of critical importance is the growing data indicating that swallow therapy and physical therapy may prevent or ameliorate long-term functional deficits. Oral health complications of head and neck therapy may manifest months or years after the completion of treatment. Patients with hyposalivation are at high risk for dental caries and thus require aggressive oral hygiene regimens and routine dental surveillance. Swallowing abnormalities, xerostomia, and poor dentition may result in dietary adaptations that may cause nutritional deficiencies. Identification and management of maladaptive dietary strategies are important for long-term health. Follow-up with primary care physicians for management of comorbidities such as diabetes and hyperlipidemia may help to limit late vascular complications caused by radiation therapy. Herein, we review late effects of head and neck cancer therapy, highlighting recent advances.

Late sensorial alterations in different radiotherapy techniques for nasopharyngeal cancer

Intensity-modulated radiation therapy (IMRT) for nasopharyngeal cancer (NPC) allowed a better distribution of the dose to the tumor volume, sparing surrounding structures. Aim of the study is the objective evaluation of olfactory and gustatory impairments in patients who underwent chemo-radiotherapy for NPC. Correlation between smell and taste alterations, xerostomy, and radiation technique was investigated. Thirty healthy subjects and 30 patients treated with chemo-radiation therapy for NPC, with at least a 2-years follow-up period, were evaluated. All subjects underwent symptoms evaluation, endoscopic fiber optic nasal examination, taste strips, Sniffin' sticks tests, Radiation Therapy Oncology Group/European Organisation for Research and Treatment of Cancer late radiation morbidity scoring system. Patients were divided in 2 groups: 2-dimensional radiotherapy/conformal 3-dimensional radiotherapy and IMRT. A higher percentage of rhinorrhea, nasal obstruction, xerostomy, hyposmia, hypogeusia, mucosal hyperemia, and presence of nasopharyngeal secretions was found in irradiated subjects (P < 0.05). Concerning olfactory and gustatory scores, we demonstrated a statistically significant difference between healthy subjects and irradiated patients (P < 0.05), with lower gustatory total score in IMRT group (P < 0.01). In conclusion, chemo-radiotherapy for NPC induces long-term smell and taste impairments, which can compromise quality of life. Although based on small samples, it is also important to consider that IMRT can induce higher taste dysfunction compared with traditional techniques.

Taste and smell disturbances after brain irradiation: a dose-volume histogram analysis of a prospective observational study

PURPOSE

Radiation-induced taste and smell disturbances are prevalent in patients receiving brain radiation therapy, although the mechanisms underlying these toxicities are poorly understood. We report the results of a single institution prospective clinical trial aimed at correlating self-reported taste and smell disturbances with radiation dose delivered to defined areas within the brain and nasopharynx.

METHODS AND MATERIALS

Twenty-two patients with gliomas were enrolled on a prospective observational trial in which patients underwent a validated questionnaire assessing taste and smell disturbances at baseline and at 3 and 6 weeks after commencement of brain radiation therapy. Fourteen patients with glioblastoma, 3 patients with grade 3 gliomas, and 5 patients with low grade gliomas participated. Median dose to tumor volume was 60 Gy (range, 45-60 Gy). Dose-volume histogram (DVH) analysis was performed for specific regions of interest that were considered potential targets of radiation damage, including the thalamus, temporal lobes, nasopharynx, olfactory groove, frontal pole, and periventricular stem cell niche. The %v10 (percent of region of interest receiving 10 Gy), %v40, and %v60 were calculated for each structure. Data from questionnaires and DVH were analyzed using stepwise regression.

RESULTS

Twenty of 22 patients submitted evaluable questionnaires that encompassed at least the entire radiation therapy course. Ten of 20 patients reported experiencing some degree of smell disturbance during radiation therapy, and 14 of 20 patients experienced taste disturbances. Patients reporting more severe taste toxicity also reported more severe toxicities with sense of smell (r(2) = 0.60, P < .006). Tumor location in the temporal lobe predicted for increased severity of taste toxicity (F3, 16 = 1.44, P < .06). The nasopharynx was the only structure in which the DVH data predicted the presence of radiation-induced taste changes (r(2) = 0.28, P < .02).

CONCLUSIONS

Radiation-induced taste toxicity appears to be more common in temporal lobe tumors, and may be related to the dose received by the nasopharynx.

The role of the general dental practitioner in managing the oral care of head and neck oncology patients

The general dental practitioner (GDP) plays a critical role in managing head and neck cancer patients. The first and most important role is to offer preventive services, particularly to smokers and to patients who drink alcohol to excess. It is of critical importance that every patient has a systematic examination of oral soft tissues when seen by a GDP. All patients with suspicious lesions should be referred for urgent attention to a specialist centre. Once oral cancer has been diagnosed, GDPs may be presented with patients requiring urgent dentistry, including extractions before commencement of treatment, requiring palliation of symptoms during treatment, or requiring general dentistry after treatment. Radiotherapy provides increased survival but has serious adverse consequences, which may be lifelong, including dry mouth, radiation caries, limitation of mouth opening and high risk of osteonecrosis after extractions. Extraction of teeth in irradiated bone should be referred to specialist centres. Improving survival rates and an ageing population mean that GDPs will see many more survivors of head and neck cancer in the future, with an increased burden of dental care in the longer-term and an increased need for monitoring and secondary prevention.

CLINICAL RELEVANCE

The management of patients with head and neck cancer is complex and involves a multi-disciplinary team, both in the primary treatment but also in the long-term care. This paper reviews the consequences of treatment for head and neck cancer and gives practical advice for GDPs and their team in the long-term care of these patients.

Oral complications of cancer and cancer therapy: from cancer treatment to survivorship

Answer questions and earn CME/CNE Oral complications resulting from cancer and cancer therapies cause acute and late toxicities that may be underreported, underrecognized, and undertreated. Recent advances in cancer treatment have led to changes in the incidence, nature, and severity of oral complications. As the number of survivors increases, it is becoming increasingly recognized that the aggressive management of oral toxicities is needed to ensure optimal long-term oral health and general well-being. Advances in care have had an impact on previously recognized oral complications and are leading to newly recognized adverse effects. Here, the authors briefly review advances in cancer therapy, including recent advances in surgery, oral care, radiation therapy, hematopoietic cell transplantation, and medical oncology; describe how these advances affect oral health; and discuss the frequent and/or severe oral health complications associated with cancer and cancer treatment and their effect upon long-term health. Although some of the acute oral toxicities of cancer therapies may be reduced, they remain essentially unavoidable. The significant impact of long-term complications requires increased awareness and recognition to promote prevention and appropriate intervention. It is therefore important for the primary oncologist to be aware of these complications so that appropriate measures can be implemented in a timely manner. Prevention and management is best provided via multidisciplinary health care teams, which must be integrated and communicate effectively in order to provide the best patient care in a coordinated manner at the appropriate time.

Mechanisms of taste bud cell loss after head and neck irradiation

Taste loss in human patients following radiotherapy for head and neck cancer is a common and significant problem, but the cellular mechanisms underlying this loss are not understood. Taste stimuli are transduced by receptor cells within taste buds, and like epidermal cells, taste cells are regularly replaced throughout adult life. This renewal relies on progenitor cells adjacent to taste buds, which continually supply new cells to each bud. Here we treated adult mice with a single 8 Gy dose of x-ray irradiation to the head and neck, and analyzed taste epithelium at 1-21 d postirradiation (dpi). We found irradiation targets the taste progenitor cells, which undergo cell cycle arrest (1-3 dpi) and apoptosis (within 1 dpi). Taste progenitors resume proliferation at 5-7 dpi, with the proportion of cells in S and M phase exceeding control levels at 5-6 and 6 dpi, respectively, suggesting that proliferation is accelerated and/or synchronized following radiation damage. Using 5-bromo-2-deoxyuridine birthdating to identify newborn cells, we found that the decreased proliferation following irradiation reduces the influx of cells at 1-2 dpi, while the robust proliferation detected at 6 dpi accelerates entry of new cells into taste buds. In contrast, the number of differentiated taste cells was not significantly reduced until 7 dpi. These data suggest a model where continued natural taste cell death, paired with temporary interruption of cell replacement, underlies taste loss after irradiation.

Taste dysfunction in head and neck malignancy

Disturbance of taste is common following radiotherapy of head and neck malignancy, that adversely affect systemic health and quality of life. Therapy remains problematic and there is thus a need for effective preventative and curative strategies for radiotherapy-associated taste disturbance. The present article reviews current knowledge of taste dysfunction associated with head and neck malignancy.

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.

Can dietary supplementation of monosodium glutamate improve the health of the elderly?

Dietary free l-glutamate has been known for a century to improve taste and palatability. Recent evidence suggests that this effect is mediated through specific l-glutamate receptors located on the taste buds. However, l-glutamate receptors are also present elsewhere in the gastrointestinal tract, such as the stomach. Here, l-glutamate exerts physiologic actions beneficial to gut function by stimulating l-glutamate receptors linked to the gastric vagus nerve. In addition, dietary l-glutamate also appears to be an important energy substrate for gut tissue. Can such l-glutamate effects on taste and gut function be clinically useful? Elderly people often develop health problems related to their nutritional status that can be linked to insufficient energy and nutrient intake. A number of studies have examined the potential usefulness of l-glutamate, added to food in the form of monosodium glutamate (MSG), in promoting better nutrition in the elderly and in patients with poor nutrition. Some positive effects have been observed. This article reviews the physiologic roles of dietary l-glutamate in relation to alimentation and examines the evidence linking the utility of MSG supplementation to the improvement of nutrition in elderly and hospitalized patients.

Effectiveness of the cough reflex in patients with aspiration following radiation for head and neck cancer

The effectiveness of the cough reflex in patients who aspirated following radiation for head and neck cancer was evaluated in 89 patients (49 chemoradiation, 33 postoperative radiation, and 7 radiation alone). All patients had modified barium swallow because of dysphagia. The cough reflex was graded as present and effective, ineffective, intermittently effective, or absent. All patients were cancer-free at the time of the swallowing study. The cough reflex was present and effective in 46 patients (52%), ineffective in 17 patients (19%), and absent in 26 patients (29%) on initial investigation. Among the 43 patients who had ineffective or absent cough reflex, their treatment was chemoradiation (26), postoperative radiation (13), and radiation alone (4). In 30 patients who had sequential modified barium swallow, the cough reflex was constantly effective, ineffective, or intermittently effective in 12 (40%), 13 (43%), and 5 (17%) patients, respectively. The cough reflex was frequently ineffective or absent in patients who aspirated following radiation for head and neck cancer. Cough may also be intermittently ineffective to protect the airways following radiation.

Radiotherapy-induced taste impairment

Changes in taste perception occur in a significant proportion of cancer patients. Among cancer patients treated with radiotherapy (RT) in head and neck area, the vast majority reports an altered taste sense during and after treatments. Taste impairment starts a few weeks after the beginning of irradiation, and almost all such patients experienced loss of taste acuity at a dose of 60 Gy. Some studies investigated the four basic taste intensities (sweet, salty, sour and bitter) and the umami taste, and several of these reports identified diminished threshold sensitivity for at least one taste quality. Six months to one year after RT, taste acuity recovers to its previous level in many patients, but some patients show incomplete or no recovery even several years later. Taste impairment has profound effects on patients' quality of life because is associated with weight loss through reduced appetite and altered patterns of food intake. Damage to the major salivary glands during head and neck RT leads to disturbance in taste acuity. With the implementation of new radiation techniques, such as conformal and intensity-modulated RT in head and neck irradiation, the late-radiation effects can probably be reduced, but the remaining sequelae are still bothersome to the patients.

Aspects of taste and compliance in patients with cancer

Taste alterations are common in patients with cancer, and can be the result of the disease itself and/or its treatment(s). Specifically, chemotherapy and/or radiotherapy to the head and neck area have been shown to induce significant taste changes. Alterations in taste are distressing for patients and can lead to food aversions, a reduction in food intake and nutritional deficits. Ultimately, this can lead to weight loss and, in severe cases, malnutrition, which has been associated with poor patient outcomes, including a negative effect on survival. Dietary counselling and advice tailored to the individual can improve nutritional status, and several effective strategies are available to accommodate taste changes and increase nutritional intake. Oral supplements may provide additional nutritional support when dietary intake is insufficient. The success of supplementation depends, however, on the product acceptability and on patient compliance over the long term. Patient compliance is linked to perceived supplement taste, which may be affected by a variety of taste changes reported by patients both before and after therapy, or as a consequence of disease progression. Supplements which offer a variety of flavours are likely to prove beneficial by helping to prevent taste fatigue. In addition, individuals appear to exhibit distinct preferences for particular flavours at different time points during treatment.