Following successful surgery for early breast cancer, patients aged 75 to 79 had a higher risk for distant recurrence than patients aged 70-74 years, according to results from a large population-based study presented at the ESMO Breast Cancer 2019, held 2 to 4 May in Berlin, Germany.
Prediction tools that take competing mortality into account by including comorbidity or other geriatric parameters could play an important role in improving breast cancer management in older patients.
Anna Z. de Boer, Department of Surgery, Leiden University Medical Centre in Leiden, Netherlands and colleagues identified patients in the Netherlands Cancer Registry aged 70 years and older who were diagnosed with early stage breast cancer and underwent surgery from 2003 to 2009.
The investigators calculated the cumulative incidence of locoregional and distant recurrence according to age categories using the Cumulative Incidence Competing Risks (CIRC) method. In addition, the Fine and Gray model was used to estimate the effect of age on recurrence, which was expressed as subdistribution hazard ratio (sHR).
Patients aged 75 to 79 years had the highest risk of distant recurrence
This analysis included 18,419 patients who were stratified according to age: 70-74 years (reference group), 75-79 years, and ≥80 years. Nine-year cumulative incidences of locoregional recurrence were 2.5%, 3.1% and 2.9% in patients aged 70-74, 75-79 and ≥80 years, and 10.9%, 15.9% and 12.7% for distant recurrence.
In univariate analysis, the two higher age groups (age 75-79 years and ≥80 years) were associated with a higher risk of locoregional and distant recurrence compared to the reference age group of 70-74 years.
According to the multivariable analysis, which adjusted for tumour and treatment characteristics, the risk of distant recurrence remained significantly higher for patients aged 75-79 (sHR 1.25; 95% confidence interval [CI], 1.11-1.41; p < 0.001).
Stacked cumulative incidences of distant recurrence and competing mortality by age group. ©Anna Z. de Boer.
However, this increased risk was not observed for patients aged ≥80 years (sHR 1.03; 95% CI, 0.91-1.17; p = 0.606).
No significant association between age and locoregional recurrence risk was found in the multivariable analysis.
Conclusions
The authors concluded that this large population-based study showed that patients aged 75 to 79 years were at increased risk of distant recurrence compared to the reference group of patients aged 70 to 74 years despite the higher competing mortality risk.
They offered the possible explanations of decreased treatment effectiveness with age and undertreatment, emphasising the importance of improving treatment strategies for older patients with breast cancer.
Disclosure
Funding for this study was provided by ZonMw.
Reference
87O - de Boer AZ, van der Hulst HC, van der Plas-Krijgsman W, et al. Impact of older age on the locoregional and distant breast cancer recurrence risk; a large population-based study. ESMO Breast Cancer 2019; 2-4 May, Berlin, Germany.