Taste problems and xerostomia (dry mouth) are common among patients with advanced cancer. These symptoms can affect the pleasure of eating and drinking, reduce dietary intake, cause low mood, and a lower quality of life. This study will explore the relationship between dry mouth and taste problems in patients with advanced cancer.

Patients with advanced cancer often develop taste disturbances. A recent literature review reported a median prevalence of 55%, with prevalence ranging from 27-93%. Studies have shown taste disturbance is usually a persistent symptom, is often 'moderate-to-severe' in intensity, and is often associated with significant distress. Taste disturbance may have a major impact on the experience and pleasure associated with eating and drinking. Taste disturbance may have a major impact on nutritional intake. It may be associated with low mood / depression, social isolation, and an impaired quality of life.

There is limited data available on the aetiology of taste disturbances in patients with advanced cancer, although one group of researchers reported an association between the severity of xerostomia (subjective sensation of dry mouth) and the severity of taste disturbance. Several studies have identified xerostomia and taste disturbance in symptom clusters.

Xerostomia (dry mouth) is defined as the subjective complaint of dry mouth. The prevalence of xerostomia in patients with advanced cancer has been reported to be >80%. It is the most common oral symptom in patients with advanced cancer. Xerostomia is often a distressing symptom, and is associated with a number of complications including oral discomfort, lip discomfort, cracking of lips, taste disturbances, difficulty chewing, difficulty swallowing, decreased intake of nutrition, oesophagitis, difficulty speaking, poor oral hygiene, halitosis, dental caries, salivary gland infections, oral candidiasis, pneumonia, dental demineralisation (causing dental sensitivity), denture fitting problems, oesophagitis, sleep disturbance, embarrassment, anxiety, depression, and social isolation.

The aforementioned literature review identified the need for observational studies to determine the prevalence, clinical features, "risk factors" and aetiologies for taste disturbance- this data would facilitate targeted screening for the problem. Studies have shown that taste disturbances and xerostomia often co-exist. To the researcher's knowledge, there no evidence on the effect of xerostomia or its treatment on taste problems. This study will explore the relationship between xerostomia and taste problems in patients with advanced cancer.

Inclusion Criteria:

• 18 years of age
• Diagnosis of locally advanced or metastatic cancer
• Referred to palliative care/oncology services
• Dry mouth rated 'moderate' or worse over previous 2-week period
• Taste problems rated 'moderate' or worse over previous 2-week period
• Good understanding of English

Exclusion Criteria:

• Cognitive impairment (unable to provide consent / complete questionnaire)
• Dry mouth precedes cancer diagnosis.
• Taste problems precedes cancer diagnosis.
• Head and neck surgery
• Head and neck radiotherapy
• Salivary gland disorders (e.g., Sjogren's Syndrome)
• In the 'Deteriorating' or 'Terminal' Phase of illness

Patients who are currently under the care of oncology or palliative care who have an incurable cancer. Patients will be identified by the clinical teams at the study sites, informed about the study, and (if interested in taking part in the study) referred to the research team.

Participants will be screened for inclusion by asking, "1. Over the last 2 weeks have you experienced having a dry mouth? 2. Over the past 2 weeks have you experienced taste problems?" If yes to either question, "How severe was it? (Options- Slight/Moderate/Severe/Very severe)". Patients must score as moderate/severe/very severe.

There is not a plan to make IPD available.