Smak- och luktförändringar vid cytostatikabehandling

Abstract

Patients undergoing cancer chemotherapy typically experience multiple symptoms, side effects and/or treatment-related problems. Taste and smell changes (TSCs) can be among these but can also be related to a variety of other causes. This thesis focuses on chemotherapy-related TSCs, which previously have been under-investigated.

Aim: This thesis applies mixed methods to investigate the experience of TSCs among cancer patients receiving chemotherapy on an out-patient basis, including resulting distress, impact on daily life, and self-care strategies for TSC management.

Methods: Two explorative studies were conducted. The first is a longitudinal qualitative interview study of 21 patients reporting TSCs. This study was used to construct the second study, a survey which was completed by 518 patients receiving chemotherapy for >6 weeks at one of 11 out-patient units at 4 hospitals in Sweden. Paper IV mixes data from both studies to investigate smell changes occurring in the absence of taste changes.

Results: Paper I: The qualitative analysis showed great individual variation in patterns, intensity and impact of TSCs with changes reported to have ceased in all participants within 3.5 months after treatment ended. While not all participants found reported changes bothersome , those who did reported predominately emotional and social consequences. Smell and taste changes were said to be influenced by or influence other symptoms, e.g. appetite loss, early satiation, nausea and oral problems. Although participants said they lacked ways to manage chemosensory changes, coping strategies described included frequent oral hygiene, searching for tolerable food, relying on smell and taste memory and acceptance of changes. Paper II: It was found that 75 % of the 518 participants reported TSCs, with TSCs more prevalent among women and younger patients. After adjustment for age and sex, we found that patients reporting TSCs more often reported: previous smell changes, less responsibility for cooking, concurrent medication, higher educational levels, and being on sick leave. Participants reporting oral problems, nausea, appetite loss, and depressed mood more frequently reported TSCs. Diagnosis and type of chemotherapy regimen did not predict TSCs. Paper III: Nearly 1/3 of the 340 participating patients with TSCs reported both high levels of distress and impact on daily life (HDHI) from TSCs. The HDHI subset reported other symptoms more often than other subsets, and also more often responded to open questions about distress, impact and self-care strategies. TSCs were not always reported to staff, even in the HDHI subset. The specific aspects of TSCs resulting in distress and impact on daily life varied greatly, affecting both psychological and somatic aspects, with little consensus and great individual differences described in self-care strategies. Paper IV: All 43 participants reporting SCs alone reported increased sensitivity to one or several odours, with no participants reporting decreased sensitivity. Those reporting SCs significantly more often reported weight gain than those reporting TSCs, with oral problems and appetite loss significantly less common. There were no differences in reported nausea between SC and TSC groups, but nausea was more common in the SC group than in those without TSCs. The case study reports are linked to and discussed in relation to possible explanatory models for increased olfactory sensitivity, e.g. anticipatory nausea, pseudo-hallucinations, and increased chemical sensitivity. SCs increase during chemotherapy, were often unpredictable and led to emotional consequences.

Conclusions: The reported variation in experiences of TSCs makes these side effects especially challenging to assess and alleviate. The variety of distress, impact, and strategies used to alleviate TSCs clarifies the importance of situational meaning. TSCs were also found to be closely related to many other side effects of chemotherapy. All participants experience smell changes without taste changes reported increased sensitivity to one or several smells and it seems to increase during chemotherapy, was unpredictable and led to emotional consequences.