A Prospective Trial on Initiation Factor 4E (eIF4E) Overexpression and Cancer Recurrence in Node-Negative Breast Cancer

Abstract

Eukaryotic Initiation Factor 4E (eIF4E) plays a crucial role in translation control. High eIF4E increase in tumor specimens independently predicted recurrence by multivariate analysis. This prospective trial of node-negative only breast cancer patients was initiated to test the hypothesis that high eIF4E increase predicts cancer recurrence and death, independent of nodal status. The trial was powered to detect a 2.4-fold increase in relative risk for cancer recurrence in 240 node-negative patients on the basis of high versus low eIF4E increase in tumor specimens (type I error = .05, statistical power = .08). eIF4E level was quantified by using Western blot test. Treatment and surveillance regimens were standardized. Primary endpoints were cancer recurrence and cancer-related death. Of the 242 patients accrued, 112 were in the low eIF4E group (<7.5-fold), 82 were in the intermediate eIF4E group (7.5- to 15-fold), and 48 were in the high eIF4E group (>15-fold). Patients in the high eIF4E group had a statistically significant higher rate of cancer recurrence and cancer-related death (P = .0001 and P < or = .0001, log rank test). The relative risk for cancer recurrence was 2.2-fold higher in the high eIF4E group (P = .001, Cox model), and 3.7-fold higher for cancer-related death (P = .0009). In node-negative breast cancer, high eIF4E increase predicted a higher rate of cancer recurrence and death. High eIF4E patients had a >2-fold increase in relative risk for cancer recurrence and nearly a 4-fold increase in relative risk for death. This supports our hypothesis that high eIF4E is an independent predictor for breast cancer outcome independent of nodal status.