High STAT5a expression was significantly associated with favorable survival in bladder cancer (lnHR = −0.8689 [−1.4087, −0.3292], P-value = 0.0016), breast cancer (lnHR = −0.7805 [−1.1394, −0.4215], P-value < 0.0001) and lung cancer (lnHR = −0.3255 [−0.6427, −0.0083], P-value = 0.0443). This evidence concerns the gene STAT5A and breast cancer.