Abstract P6-09-10: All-cause survival estimates compared to observed survival in older women with breast cancer in CALGB 49907 and 369901 (Alliance A151503)
Authors: Kimmick G , Pitcher B , Mandelblatt J , Clapp J , Ballman K , Barginear M , Freedman R , Artz A , Klepin H , Lafky J , Hopkins J , Winer E , Hudis C , Muss H , Cohen H , Jatoi A , Hurria A 
Published: May 2016

Background: Older adults represent 50% or more of all newly diagnosed cancer patients annually; these patients have multiple morbidities, complicating treatment decision-making.. Discussions about the risks and benefits of cancer treatments might be improved by having data on estimated all-cause survival. ePrognosis (http://eprognosis.ucsf.edu/carey2.php) is an online tool validated in older adults without cancer. We compared survival estimates using ePrognosis to observed survival in a population of women with early stage breast cancer who volunteered for cooperative group studies.

Methods: Participants in CALGB 49907 (n=194) and 369901 (n=809) who were age 70+ were included (total n=1003). Both studies had comparable eligibility: primary, newly diagnosed, invasive, non-metastatic breast cancer. In 49907, eligibly also included PS 0-2; in 369901 there were no PS restrictions, but women who failed a screening cognitive exam were excluded. The Carey 2-year Index from ePrognosis was used to estimate all-cause 2-year survival, based on age, sex, and daily function. Function (needing help from another person to bath and shop for groceries, difficulty walking several blocks and pushing or pulling a heavy object) was derived from the EORTC QLC-30. The Carey index from ePrognosis generates scores from 1-10, with higher scores indicating higher probability of death. Kaplan-Meier methods were used to obtain point estimates and confidence intervals for the observed 2-yr survival. A two sided z-test was used to test the hypothesis that the observed survival rate is equivalent to the predicted survival rate.

Results: At two years from study entry, 921 women were alive; 56 had died, and 26 were lost to follow-up/withdrawn. The population was, on average, 76 years old (SD 4.8), primarily white (89.3%), and the majority had hormone receptor positive tumors (79.4%). In our population, the Carey 2-years index predicated survival was not significantly different than observed rates in the 0-2 points and underestimated the survival rates for patients who had 3-6 points and 7-10 points.

ePrognosis Prediction49907 & 369901 PatientsPointsPredicted Probability of SurvivalNNumber of DeathsObserved Probability of Overall Survival at 2 years (%, 95% CI)p-value0-295%5332595% (93-97%)0.7433-688%4272394% (92-96%)&lt;0.0017-1064%43881% (65-90%)0.017

Conclusions: In this population of older women with breast cancer, using a few readily available data items, ePrognosis provided accurate survival estimates for women with a low probability of death (0-2 points) and underestimated all-cause survival in women with an increased probability of death (3-10 points). Further studies are needed to assess the validity of this tool in samples of cancer patients with higher risks of 2-year mortality. Extended follow-up to validate the tools in predicting 5- and 10-year all-cause and non-cancer mortality risk will further contribute to decision making in older patients.

Citation Format: Kimmick G, Pitcher B, Mandelblatt J, Clapp J, Ballman K, Barginear M, Freedman R, Artz A, Klepin H, Lafky J, Hopkins J, Winer E, Hudis C, Muss H, Cohen H, Jatoi A, Hurria A. All-cause survival estimates compared to observed survival in older women with breast cancer in CALGB 49907 and 369901 (Alliance A151503). [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P6-09-10.