Cancer therapy-related salivary dysfunction

Salivary gland dysfunction is a common side effect of cancer treatments. Salivary function plays key roles in critical daily activities. Consequently, changes in salivary function can profoundly impair quality of life for cancer patients. We discuss salivary gland anatomy and physiology to understand how anticancer therapies such as chemotherapy, bone marrow transplantation, immunotherapy, and radiation therapy impair salivary function. We discuss approaches to quantify xerostomia in the clinic, including the advantages and limitations of validated quality-of-life instruments and approaches to directly measuring salivary function. Current and emerging approaches to treat cancer therapy-induced dry mouth are presented using radiation-induced salivary dysfunction as a model. Limitations of current sialagogues and salivary analogues are presented. Emerging approaches, including cellular and gene therapy and novel pharmacologic approaches, are described.

Effect of different approaches of direct radiation on the surface structure and caries susceptibility of enamel

It is not clear whether different radiation methods have different effects on enamel. The purpose of this study was to compare the effects of single and fractionated radiation on enamel and caries susceptibility and to provide an experimental basis for further study of radiation‑related caries. Thirty-six caries-free human third molars were collected and randomly divided into three groups (n = 12). Group1 (control group) was not exposed to radiation. Group 2 received single radiation with a cumulative dose of 70 Gy. Group 3 underwent fractionated radiation, receiving 2 Gy/day for 5 days followed by a 2-day rest period, for a total of 7 weeks with a cumulative dose of 70 Gy. Changes in microhardness, roughness, surface morphology, bacterial adhesion and ability of acid resistance of each group were tested. Scanning electron microscope revealed that the enamel surface in both radiation groups exhibited unevenness and cracks. Compared with the control group, microhardness and acid resistance of enamel decreased, while roughness and bacterial adhesion increased in both the single radiation and fractionated radiation groups. Compared with the single radiation group, the enamel surface microhardness and acid resistance decreased in the fractionated radiation group, while roughness and bacterial adhesion increased. Both single radiation and fractionated radiation resulting in changes in the physical and biological properties of enamel, with these changes being more pronounced in the fractionated radiation group. Therefore, fractionated radiation is recommended as a more suitable method for constructing a radiation‑related caries model in vitro.

Knowledge about dental care in patients with head and neck cancer among senior dental school students: a cross-sectional descriptive study

BACKGROUND

The dentist's central role in treating head and neck cancer patients is to care for the patient's oral cavity before, during, and after radio/chemotherapy. This research aimed to determine dental students' knowledge about head and neck cancer patients' dental care.

METHODS

One hundred and four fifth and sixth-year dental students participated in this cross-sectional descriptive study. The data collection tool was a questionnaire that collected demographic information (gender, year of study) and four questions consisting of attendance to courses or workshops, passing a dedicated course at the university, willing to participate in a course or workshop on the treatment of head and neck cancer patients and self-evaluating information about the treatment of head and neck cancer patients. Final part 36 questions about oral and dental care for head and neck cancer patients before, after, and during treatment. The data were analyzed with SPSS 26 statistical software and using t-tests, ANOVA, and linear regression at the 0.05 significance level.

RESULTS

Most of the participants were in their sixth year (48.9%). A total of 48.1% of the people reported that their information about dental treatments in patients with head and neck cancer was bad. 85% of participants agreed with the necessity of evaluating the patient's mouth and teeth before starting the treatment. The lowest percentage of correct answers was related to the ideal duration of tooth extraction and a poor prognosis before the start of cancer treatment. The regression analysis revealed a significant relationship between years of education, willingness to participate in courses, and students' knowledge evaluation and knowledge.

CONCLUSION

The findings showed that students' awareness of oral and dental treatment and care for patients with head and neck cancer is insufficient. It is recommended that teaching staff pay more attention to the lack of knowledge and effort to educate students by holding special courses and workshops.

Compliance with oral hygiene and dietary advice for the prevention of post-radiotherapy dental disease among head and neck cancer patients - a qualitative study

OBJECTIVES

To elicit head and neck cancer (HANC) patients' views about their oral health and to identify potential issues regarding compliance with clinical oral hygiene and dietary advice for the prevention of post-radiotherapy dental disease.

METHODS

A purposive sample of twelve HANC patients between 6- and 12-months post-radiotherapy were recruited to undergo a semi-structured interview with a qualitative researcher. A pre-piloted topic guide was used to frame each interview. Qualitative data were analysed via thematic analysis.

RESULTS

Data were categorised into four main themes - 'How HANC patients perceive oral health', 'Cancer diagnosis and cancer care pathway', 'Impact of oncology treatment (radiotherapy, surgery, and chemotherapy)', and 'Post-oncology treatment recovery', with 14 subthemes. Oral health was viewed as an important component of HANC patients' overall physical and mental health post-treatment. Patients' non-compliance with adequate oral hygiene practice was related to oral mucositis, a "burning" sensation associated with high fluoride toothpaste, forgotten or inconsistent clinical advice, and an inadequate supply of preventive oral hygiene products. The potentially highly cariogenic nature of prescribed nutritional supplements for patients at risk of malnutrition did not tend to be communicated to patients in advance of their prescription.

CONCLUSIONS

Adequate oral health is essential for the overall physical and mental well-being of post-treatment HANC patients. Non-compliance with preventive clinical advice increases the risk of post-treatment oral health deterioration and was related to miscommunication, inadequate supplies of oral hygiene products, and treatment-related oral discomfort.

CLINICAL SIGNIFICANCE

Post-treatment HANC patients are at increased risk of dental disease. Educational and behavioural techniques should be employed to enhance patients' compliance with clinical oral hygiene and dietary advice for the prevention of post-radiotherapy dental disease. Patients should be informed about the potentially highly cariogenic nature of nutritional supplements, and these patients should undergo frequent dental recall. Clinical advice regarding oral hygiene and dietary practices needs to be given consistently to HANC patients by different specialists of the HANC multidisciplinary team.

Quantification of very late xerostomia in head and neck cancer patients after irradiation

Objective

Radiation therapy (RT) for head and neck cancer (HNC) can result in severe xerostomia, or the subjective feeling of dry mouth. Characterizing xerostomia is critical to designing future clinical trials investigating how to improve HNC patients' quality of life (QoL). Few studies have investigated the very late (>5 years post-RT) effects of RT for HNC. We undertook preliminary studies quantifying very late xerostomia.

Methods

Six adults who underwent RT for HNC at least 5 years prior and reported xerostomia were enrolled. Five healthy adults without a self-reported history of HNC or xerostomia were enrolled as controls. All participants completed three validated surveys to measure xerostomia-related QoL. Salivary production rates were measured and compositional analysis of the saliva and oral microbiome was completed.

Results

The QoL survey scores for the HNC participants were significantly worse as compared to the control participants. The HNC participants produced less unstimulated saliva (p = .02) but not less stimulated saliva. The median salivary mucin significantly higher in HNC participants than in control participants (p = .02). There was no significant difference between the pH, amylase, or total protein. Microbiome analysis revealed alpha diversity to be significantly lower in the HNC participants.

Conclusion

In the survivors of HNC who suffer from late toxicities, multiple means of measuring toxicity may be useful. We found that in patients with radiation-induced xerostomia over 5 years after therapy, not only were the QoL surveys significantly worse, as expected, but other measurements such as mucin and oral microbiome diversity were also significantly different.

Level of evidence

3.

Stimulated saliva composition in patients with cancer of the head and neck region

BACKGROUND

To analyse over time changes in stimulated whole saliva regarding total protein, Immunoglobulin A (IgA), and mucin type O-glycans (mostly MUC5B and MUC7) in head and neck cancer patients.

METHODS

29 dentate patients (20 men and 9 women, 59 ± 8 years) treated with curative radiation therapy and chemotherapy for cancer of the head and neck region were included. The stimulated whole salivary secretion rate was determined and saliva collected at four time-points: at pretreatment, and at 6 months, 1 and 2 years post treatment. The total protein concentration was determined spectrophotometrically by using Bicinchoninic Acid assay and Immunoglobulin A (IgA) by using ELISA technique. Glycosylation pattern of salivary mucins was determined in samples collected pre- and post treatment by using LC/MS electrospray and mucin content quantified using SDS-AgPAGE gels and PAS staining.

RESULTS

Compared with pretreatment, the total protein concentration was increased already at 6 months post treatment (p < 0.01), and continued to increase up to 2 years post treatment (p < 0.001). During that period no significant changes in IgA concentration was detected. At pretreatment, the output/min of both total protein and IgA was significantly higher than at all time-points post treatment. Saliva from the cancer patients showed a low abundance/no detectable MUC7, while the MUC5B level remained, compared to saliva from a healthy control. The glycomic analysis showed that the percentage of core 2 O-glycans was increased as core 1, 3 and 4 O-glycans were decreased. The level of sialylation was higher at 6 months post treatment, while sulfation was lower.

CONCLUSION

A decreased output per minute of proteins at decreased salivary secretion rate, as well as reduced sulfation of MUC5B at 6 months post treatment tended to correlate with the patients' experience of sticky saliva and oral dryness. At 2 years post treatment, the decreased amount of IgA combined with a lowered salivary secretion rate indicate a reduced oral defense with increased risk of oral infections.

Variations in odontological care routines for patients undergoing treatment for head and neck cancer in county councils/regions of Sweden

OBJECTIVE

To investigate current odontological care routines for patients treated for head and neck cancers in the county councils/regions (C/Rs) of Sweden.

METHODS

An invitation to fill in a web-based questionnaire was sent to dentists/dental hygienists working in dental clinics in the 12 C/Rs, treating and responsible for the odontological care of patients undergoing treatment for cancer of the head and neck. The questionnaire started with two mandatory and one non-mandatory questions, followed by questions regarding routines before (n = 28), during (n = 23), and after (n = 9) treatment, plus two additional questions, totalling 65 questions.

RESULTS

Four dental hygienists and six dentists in 10 of the 12 C/Rs answered the questionnaire. Three C/Rs stated that they measure both the unstimulated and stimulated salivary secretion rate, and another C/R stated that they measure the stimulated secretion rate only. Similar recommendations were given regarding oral hygiene, salivary stimulants and substitutes, and extra fluoride. However, great variations were seen regarding recommendations for preventing and relieving oral mucositis. There were also discrepancies regarding information about the importance of avoiding smoking and alcohol. In seven C/Rs, patients visited the dental hygienist once a week during cancer treatment.

CONCLUSION

The results suggests that there are great variations in odontological care given to patients undergoing treatment for cancer of the head and neck region in different county councils/regions in Sweden. There is a need to develop and implement evidence-based guidelines to decrease the risk of oral complications and increase both the quality of life and the quality of care.