Purpose: Tools to estimate survival, such as ePrognosis ( http://eprognosis.ucsf.edu/carey2.php ), were developed for general, not cancer, populations. In older patients with breast cancer, accurate overall survival estimates would facilitate discussions about adjuvant therapies.
Methods: Secondary analyses were performed of data from two parallel breast cancer studies (CALGB/Alliance 49907/NCT000224102 and CALGB/Alliance 369901/NCT00068328). We included patients (n = 971) who were age 70 years and older with complete baseline quality of life data (194 from 49907; 777 from 369901). Estimated versus observed all-cause two-year mortality rates were compared. ePrognosis score was calculated based on age, sex, and daily function (derived from EORTC QLQ-C30). ePrognosis scores range from 0 to 10, with higher scores indicating worse prognosis based on mortality of community-dwelling elders and were categorized into three groups (0-2, 3-6, 7-10). Observed mortality rates were estimated using Kaplan-Meier methods.
Results: Patient mean age was 75.8 years (range 70-91) and 73% had stage I-IIA disease. Most patients were classified by ePrognosis as good prognosis (n = 562, 58% 0-2) and few (n = 18, 2% 7-10) poor prognosis. Two-year observed mortality rates were significantly lower than ePrognosis estimates for patients scoring 0-2 (2% vs 5%, p = 0.001) and 3-6 (8% vs 12%, p = 0.01). The same trend was seen with scores of 7-10 (23% vs 36%, p = 0.25).
Conclusions: ePrognosis tool only modestly overestimates mortality rate in older breast cancer patients enrolled in two cooperative group studies. This tool, which estimates non-cancer mortality risk based on readily available clinical information may inform adjuvant therapy decisions but should be validated in non-clinical trial populations.
Keywords: Breast cancer; Elderly; Survival estimates; ePrognosis.