Hematopoietic stem cell transplant (HSCT) is a demanding cancer treatment for HSCT recipients and their caregivers. The thesis objectives were to (a) critically review the literature evaluating the psychosocial impact of being a caregiver to a HSCT patient; (b) evaluate a conceptual framework to examine the individual and dyadic experience of HSCT patients and their caregivers; and (c) gain a better understanding of how couples navigate the HSCT. Study 1 was a comprehensive literature review that demonstrated that caregiver distress is highest pre-HSCT and predictors of caregiver distress include female gender, elevated subjective burden, and higher patient symptom distress. This study also highlighted the need for theoretically driven research that examines reciprocal relationships between HSCT dyads. Study 2 proposed a conceptual model based on equity theory to examine the individual and dyadic experience of HSCT dyads that includes feelings of inequity, patient self-perceived burden (SPB), caregiver burden and distress. A cohort study with 72 HSCT patient-spousal caregiver dyads was conducted pre-HSCT. Questionnaire data was subjected to path analysis. Consistent with the model, pre-HSCT caregiver burden mediated the relationship between caregiver underbenefit and caregiver distress. Patient overbenefit was related to patient SPB, patient distress, and caregiver burden. Overall, the theoretical framework appeared to describe patient and caregivers individual experience of distress pre-HSCT, but did not as clearly encompass the dyadic experience of distress. Study 3 was a qualitative study of patient-caregiver dyads to gain insight on how some successfully navigate, whereas others have difficulties. One year post-HSCT five patient-caregiver dyads were interviewed separately (N =10). Five themes emerged. While all couples adopted patient and caregiver roles, four demonstrated effective adaptation whereas one couple experienced difficulties. Ongoing physical limitations, lack of mutual empathy and relational awareness, limited social support, and poor communication were associated with difficulty adjusting to the HSCT. This thesis provides a greater appreciation of the psychosocial challenges the patients and caregivers are experiencing and highlights that the experience of HSCT recipients and caregivers is unique and intertwined. Importantly, this thesis identifies current knowledge gaps in care of HSCT dyad, discusses its clinical implications and suggests avenues for future research.

The aim of this thesis was to investigate oral cryotherapy (OC) as prophy-laxis against oral mucositis (OM) in patients given high-dose chemotherapy for stem cell transplantation (SCT). A new mouth rinse device was tested for possible additive effect to OC. For study I-III, 78 patients were randomised to OC or standard oral care (SOC). Papers I and II showed that OC patients had significantly less severe mucositis, pain, opioid use, lower C-reactive protein and less parenteral nutrition treatment (TPN). There was no difference in relapse rate, and 5-year survival was unexpectedly significantly better in the OC group (Paper III). In paper IV, the local effect of OC on the mucosa of the mouth was investigated by the use of an infrared thermograph. Change in surface temperature in eight areas of the mouth cavity was measured after cooling of the mouth in healthy volunteers. A substantial lowering of the temperature (-12.9 °C, mean) was seen which could explain the efficacy of OC. To exclude that acute cooling in itself is traumatic, the proinflammatory cytokine IL-6 was measured in saliva and showed no increase after cooling. Paper V reported a study in 40 allogeneic SCT patients. 20 were given SOC including OC and 20 in addition received Caphosol®, a calcium phosphate mouth rinse, during chemotherapy and until day 21. Severity of mucositis, use of opioids and TPN, effects on nutrition and CRP levels were measured. No significant difference was found between the groups in any of these variables, but a non-significant trend for an advantage for the combination could be seen. IL-6 saliva levels were measured. There was a substantial increase (more than 10-fold), in mean IL-6 levels from baseline to beginning of mucositis and a weak correlation between increased IL-6 levels and severity of OM, suggesting that IL-6 in saliva may be a useful marker of the inflammatory mucosal process. This thesis demonstrates that OC is effective as prophylaxis against chemotherapy-induced OM. As a consequence of this work, OC has been introduced as the standard of care in all SCT patients in our institution.