Adjuvant! Online Performs Poorly in Older Patients With Breast Cancer in Dutch Study
In a Dutch population-based study reported in The Lancet Oncology, de Glas et al found that the Adjuvant! Online prediction tool performed poorly in older patients with early-stage breast cancer, significantly overestimating or underestimating overall survival depending on comorbidity modeling.
Adjuvant! Online, a program that predicts 10-year breast cancer recurrence, breast cancer mortality, mortality due to other causes, and expected benefits of specific adjuvant treatment options for individual patients, was developed in a patient population aged ≤ 69 years. Subsequent validation studies have included relatively small numbers of older patients.
Study Details
The study assessed the performance of Adjuvant! Online in the population-based FOCUS cohort, which included all consecutive patients aged ≥ 65 years diagnosed with invasive or in-situ breast cancer between January 1997 and December 2004 in the southwestern part of the Netherlands. Patients were included if they met Adjuvant! Online criteria: unilateral, unicentric, invasive adenocarcinoma; no evidence of metastatic or residual disease; no evidence of T4 features; and no evidence of inflammatory breast cancer. Data from all patients were analyzed using two models, one with “average for age” comorbidity status and one with individualized comorbidity status.
In total, 2,012 patients with a median age of 74.0 years were included in the analysis. Median follow-up was 9.0 years for overall survival and 6.6 years for patients without recurrence. During follow-up, 45% of patients died and 16% of patients had recurrence.
‘Average for Age’ Comorbidity Status
In the model using“average for age” comorbidity status, Adjuvant! Online overestimated 10-year overall survival by 9.8% (48.8% predicted vs 39.0% observed, P < .0001) and 10-year cumulative recurrence by 8.7% (26.9% vs 18.2%, P < .0001). The difference between predicted and observed 10-year overall survival was smallest (5.9%) in patients aged 65 to 69 years and largest (18.4%) in those aged 75 to 79 years. Overall survival and cumulative recurrence were overestimated in the majority of subgroups for age, number of comorbidities, estrogen receptor stratus, tumor grade, tumor size, positive nodes, most extensive surgery type, and type of systemic treatment.
Individualized Comorbidity Status
In the model using individualized comorbidity status, Adjuvant! Online underestimated 10-year overall survival by −17.1% (P < .0001). It accurately predicted 10-year cumulative recurrence (difference = −0.7%, P = .48), although predicted and observed cumulative recurrence differed in patients with a greater number of comorbidities both according to categorical greater comorbidity status and absolute number of comorbidities.
The C-index for overall survival was 0.75 (95% confidence interval [CI] = 0.72–0.77) for the model using “average for age” comorbidity status and 0.70 (95% CI = 0.68–0.73) for the model using individualized comorbidity status.
The investigators concluded, “Adjuvant! Online does not accurately predict overall survival and recurrence in older patients with early breast cancer.”
Gerrit-Jan Liefers, PhD, of Leiden University Medical Centre, is the corresponding author for the The Lancet Oncology article.
The study was funded by the Dutch Cancer Foundation. The study authors reported no potential conflicts of interest.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
