Differences in treatment and survival of older patients with operable breast cancer between the United Kingdom and the Netherlands – a comparison of two national prospective longitudinal multi-centre cohort studies

Background Previous studies have shown that survival outcomes for older patients with breast cancer vary substantially across Europe, with worse survival reported in the United Kingdom. It has been hypothesised that these differences in survival outcomes could be related to treatment variation. Objectives We aimed to compare patient and tumour characteristics, treatment selection and survival outcomes between two large prospective cohorts of older patients with operable breast cancer from the United Kingdom (UK) and The Netherlands. Methods Women diagnosed with operable breast cancer aged ≥70 years were included. A baseline comprehensive geriatric assessment was performed in both cohorts, with data collected on age, comorbidities, cognition, nutritional and functional status. Baseline tumour characteristics and treatment type were collected. Univariable and multivariable Cox regression models were used to compare overall survival between the cohorts. Results 3262 patients from the UK Age Gap cohort and 618 patients from the Dutch Climb cohort were included, with median ages of 77.0 (IQR: 72.0–81.0) and 75.0 (IQR: 72.0–81.0) years, respectively. The cohorts were generally comparable, with slight differences in rates of comorbidity and frailty. Median follow-up for overall survival was 4.1 years (IQR 2.9–5.4) in Age Gap and 4.3 years (IQR 2.9–5.5) in Climb. In Age Gap, both the rates of primary endocrine therapy and adjuvant hormonal therapy after surgery were approximately twice those in Climb (16.6% versus 7.3%, p < 0.001 for primary endocrine therapy, and 62.2% versus 38.8%, p < 0.001 for adjuvant hormonal therapy). There was no evidence of a difference in overall survival between the cohorts (adjusted HR 0.94, 95% CI 0.74–1.17, p = 0.568). Conclusions In contrast to previous studies, this comparison of two large national prospective longitudinal multi-centre cohort studies demonstrated comparable survival outcomes between older patients with breast cancer treated in the UK and The Netherlands, despite differences in treatment allocation

Discontinuation of adjuvant endocrine therapy and impact on quality of life and functional status in older patients with breast cancer

Purpose: Side effects are the main reason for discontinuation of adjuvant endocrine therapy in older adults. The aim of this study was to examine geriatric predictors of treatment discontinuation of adjuvant endocrine therapy within the first 2 years after initiation, and to study the association between early discontinuation and functional status and quality of life (QoL). Methods: Patients aged ≥ 70 years with stage I–III breast cancer who received adjuvant endocrine therapy were included. The primary endpoint was discontinuation of endocrine therapy within 2 years. Risk factors for discontinuation were assessed using univariate logistic regression models. Linear mixed models were used to assess QoL and functional status over time. Results: Overall, 258 patients were included, of whom 36% discontinued therapy within 2 years after initiation. No geriatric predictive factors for treatment discontinuation were found. Tumour stage was inversely associated with early discontinuation. Patients who discontinued had a worse breast cancer-specific QoL (b = − 4.37; 95% CI − 7.96 to − 0.78; p = 0.017) over the first 2 years, in particular on the future perspective subscale (b = − 11.10; 95% CI − 18.80 to − 3.40; p = 0.005), which did not recover after discontinuation. Treatment discontinuation was not associated with functional improvement. Conclusion: A large proportion of older patients discontinue adjuvant endocrine treatment within 2 years after initiation, but geriatric characteristics are not predictive of early discontinuation of treatment. Discontinuation of adjuvant endocrine therapy did not positively affect QoL and functional status, which implies that the observed poorer QoL in this group is probably not caused by adverse effects of endocrine therapy