Metastatic breast cancer (MBC) patients are almost always treated to minimize the symptom burden, and to prolong life without a curative intent. Although the prognosis of MBC patients has improved in recent years, the median survival after diagnosis is still only 3 years. Therefore, the health-related quality of life (HRQoL) should play a leading role in making treatment decisions. Heterogeneity in questionnaires used to evaluate the HRQoL in MBC patients complicates the interpretability and comparability of patient-reported outcomes (PROs) globally. In this review, we aimed to provide an overview of PRO instruments used in real-world MBC patients and to discuss important issues in measuring HRQoL. Routinely collecting symptom information using PROs could enhance treatment evaluation and shared decision-making. Standardizing these measures might help to improve the implementation of PROs, and facilitates collecting and sharing data to establish valid comparisons in research. This is a prerequisite to learn about how they could impact the clinical care pathway. In addition, the prognostic value of intensified PRO collection throughout therapy on survival and disease progression is promising. Future perspectives in the field of PROs and MBC are described.

Purpose Normative utility scores represent the health related quality of life of the general population, are of utmost importance in cost-effectiveness studies and should reflect relevant sexes and age groups. The aim of this study was to estimate EQ-5D-5L normative utility scores in a population of Dutch females, stratified by age, and to compare these scores to those of female populations of three other countries. Methods Dutch women completed the EQ-5D-5L online between January and July 2020. Mean normative utilities were computed using the Dutch EQ-5D-5L value set, stratified by age, tested for differences using the Kruskall–Wallis test, and compared to normative utility scores of female populations elsewhere. Additionally, to support the use of the Dutch EQ-5D-5L data in other settings, normative utility scores were also calculated by applying the value sets of Germany, United Kingdom and USA. Results Data of 9037 women were analyzed and the weighted mean utility score was 0.911 (SD 0.155, 95% CI 0.908–0.914). The mean normative utility scores differed between age groups, showing lower scores in older females. Compared to other normative utility scores of female populations, Dutch mean utilities were consistently higher except for age groups 18–24 and 25–34. With the three country-specific value sets, new age-specific mean normative utility scores were provided. Conclusion This study provides mean normative utility scores of a large cohort of Dutch females per age group, which were found to be lower in older age groups. Utility scores calculated with three other value sets were made available.

Background The aim of this study was to evaluate the care-related quality of life in caregivers of breast cancer patients, to assess its association with breast cancer patients’ health-related quality of life (HRQoL), and to identify its potential predictors. Methods Caregivers of breast cancer patients at six and twelve months follow up were identified through the institutes electronic patient reported outcome measurement collection tool. The Care-related Quality of Life Instrument (CarerQoL) was used to obtain CarerQoL utility scores by applying a pre-existent set of Dutch tariffs and the CarerQoL VAS score, which represented the overall happiness of caregivers. The associations between breast cancer patients’ EQ-5D-5L and EORTC QLQ-C30 scores and caregivers’ CarerQoL scores was determined with Spearman’s correlation coefficients. Associations between log transformed CarerQol scores and patient and caregiver characteristics were analyzed with multivariable linear regression analyses. Results A total of 116 completed CarerQoL questionnaires were analyzed. Most caregivers were male spouses or partners (81.4%) with a mean age of 55.7 ± 16.4. The median CarerQoL utility score was 92.4/100 and median CarerQoL VAS was 8.0/10. We found weak correlations between CarerQoL VAS scores and patients’ EQ-5D-5L utility score (0.301, p = 0.002) and EQ VAS score (0.251, p = 0.009), and between EORTC QLQ-C30 scores and CarerQol VAS (0.339, p < 0.001) and utility score (0.236, p = 0.015). There was a negative association between chemotherapy and log-transformed CarerQoL utility score (B =  − 0.063, p = 0.001) and VAS score (B =  − 0.044, p = 0.038) at six months follow-up. Conclusions This study provides the first evaluation of the CarerQoL in caregivers of Dutch breast cancer patients. Caregivers’ happiness was associated with breast cancer patients’ HRQoL. Our results can be used as reference values for future care-related quality of life evaluations. Plain English Summary Breast cancer patients face many difficulties during their cancer journey and often need the support of their caregivers. Despite the fact that successfully providing informal care can have positive effects on caregivers’ wellbeing, it may also have a negative impact on their quality of life. Monitoring the quality of life using a standardized questionnaire, such as the CarerQoL questionnaire, may result in early detection of possible quality of life issues. In this study, we evaluated 116 caregivers and found overall high CarerQoL scores. The scores showed a positive relation to the patients’ quality of life. Lower CarerQoL scores at six months after surgery were found in caregivers of patients who received chemotherapy. Our research underlines the importance to include caregivers of breast cancer patients in clinical practice, provides reference values for future research, and the results can be used to manage the caregivers’ expectations prior to treatment.