Caregivers of patients receiving long-term treatment with a tyrosine kinase inhibitor (TKI) for gastrointestinal stromal tumour (GIST): a cross-sectional assessment of their distress and burden.

BACKGROUND: TKIs are a long-term treatment for GIST, and may have an impact on caregivers. MATERIAL AND METHODS: For this cross-sectional study, patients and caregivers were both included when patients had been treated with TKIs for at least six months. Caregivers completed questionnaires including demographics, distress (Hospital Anxiety and Depression scale), burden (Self-Perceived Pressure from Informal Care) general health (RAND-36), comorbidity (Self-administered Comorbidity Questionnaire), social support (Social Support List - Discrepancies) and marital satisfaction (Maudsley Marital Questionnaire). Patients completed similar questionnaires, without 'burden'. We conducted analyses to explore differences between caregivers with low/moderate versus high levels of burden and low versus high levels of distress. RESULTS: Sixty-one out of seventy-one eligible couples (84%) were included in the analysis. The median age of the caregivers was 60 years; 66% were female and 78% were the patients' spouse. The median age of the patients was 66 years; 43% were female. Caregivers experienced high levels of burden and distress in 10% and 23%, respectively. Caregivers with high levels of burden perceived significantly lower mental health, less vitality, lower general health and high levels of distress. Significantly higher levels of burden were found in non-spouses, caregivers of patients with more treatment-related side-effects, caregivers who spent more hours caring, and those caring for more than one person. For distress, caregivers with high levels of distress perceived significantly more burden, lower social functioning, more role physical and emotional problems, lower mental health, less vitality and lower general health. Furthermore, high levels of distress were found in caregivers of more dependent patients and those caring for more than one person. CONCLUSIONS: Caregivers of the patients with GIST treated with TKI are managing well. There is a small, vulnerable group of caregivers with high levels of burden and/or distress, show more health-related problems, both physical and mental, and require adequate support.

Proof-of-concept study on the suitability of 13C-urea as a marker substance for assessment of in vivo behaviour of oral colon-targeted dosage forms.

BACKGROUND AND PURPOSE: (13)C-urea may be a suitable marker to assess the in vivo fate of colon-targeted dosage forms given by mouth. We postulated that release in the colon (urease-rich segment) of (13)C-urea from colon-targeted capsules would lead to fermentation of (13)C-urea by bacterial ureases into (13)CO(2). Subsequent absorption into the blood and circulation would lead to detectable (13)C (as (13)CO(2)) in breath. If, however, release of (13)C-urea occurred in the small intestine (urease-poor segment), we expected detectable (13)C (as (13)C-urea) in blood but no breath (13)C (as (13)CO(2)). The differential kinetics of (13)C-urea could thus potentially describe both release kinetics and indicate the gastrointestinal segment of release. EXPERIMENTAL APPROACH: The in vivo study consisted of three experiments, during which the same group of four volunteers participated. KEY RESULTS: The kinetic model was internally valid. The appearance of (13)C-in breath CO(2) (F(fermented)) and the appearance of (13)C in blood as (13)C-urea (F(not fermented)) show a high inverse correlation (Pearson's r=-0.981, P= 0.06). The total recovery of (13)C (F(fermented)+F(not fermented)) averaged 99%, indicating complete recovery of the administered (13)C via breath and blood. (13)CO(2) exhalation was observed in all subjects. This indicates that (13)C-urea was available in urease-rich segments, such as the caecum or colon. CONCLUSIONS AND IMPLICATIONS: In this proof-of-concept study, (13)C-urea was able to provide information on both the release kinetics of a colon-targeted oral dosage form and the gastrointestinal segment where it was released.