In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.

Example Input: Context: To determine the association of statin use with oncological outcomes and risk of pathologic upgrading following radical prostatectomy.', 'Using a prospectively populated database of 3042 men who underwent open radical prostatectomy, patients were grouped according to reported statin use at the time of surgery. The primary outcome was time to biochemical recurrence. The secondary outcome was risk of pathologic upgrading among a subset of 1256 patients with Gleason pattern 3\u2009+\u20093\u2009=\u20096 on biopsy. A multivariable Cox model was used to assess risk of biochemical recurrence, and multivariable logistic regression was used to assess risk of pathologic upgrading.', 'Eight hundred twenty-four men (27%) reported statin use at the time of radical prostatectomy. Statin users were older and had higher body mass index, higher Charlson Comorbidity Index, and lower pretreatment prostate-specific antigen values than statin nonusers. Over a median follow-up of 70 months (interquartile range: 36-107), a total of 455 men (15%) experienced biochemical recurrence. Statin use was not associated with biochemical recurrence (adjusted hazard ratio: 1.06, 95% confidence interval: 0.86-1.31). Of those men with biopsy Gleason 3\u2009+\u20093\u2009=\u20096 disease, 647 (52%) were upgraded to higher grade disease following radical prostatectomy; however, statin use was not associated with pathologic upgrading (adjusted odds ratio: 0.78, 95% confidence interval: 0.58-1.04).\Question: Is preoperative Statin Use at the Time of Radical Prostatectomy Associated With Biochemical Recurrence or Pathologic Upgrading?
Example Output: Preoperative statin use at the time of radical prostatectomy was not associated with biochemical recurrence or risk of pathologic upgrading in this cohort. These data add to the existing body of literature suggesting that statin use is not associated with more favorable clinical outcomes following radical prostatectomy.

Example Input: Context: To study E2F3a expression and its clinical significance in children with acute lymphoblastic leukemia (ALL).', 'We quantified E2F3a expression at diagnosis in 148 children with ALL by real-time PCR. In the test cohort (n = 48), receiver operating characteristic (ROC) curve was used to find the best cut-off point to divide the patients into E2F3a low- and high-expression groups. The prognostic significance of E2F3a expression was investigated in the test cohort and confirmed in the validation cohort (n = 100). The correlations of E2F3a expression with the clinical features and treatment outcome of these patients were analyzed.', 'ROC curve analysis indicated that the best cut-off point of E2F3a expression was 0.3780. In the test cohort, leukemia-free survival (LFS) and event-free survival (EFS) of the low-expression group were lower than those of the high-expression group (log rank: P = 0.026 for both). This finding was verified in the validation cohort. LFS, EFS, and overall survival were also lower in the low-expression group than in the high-expression group (log rank, P = 0.015, 0.008, and 0.002 respectively). E2F3a low expression was correlated with the existence of BCR-ABL fusion. An algorithm composed of E2F3a expression and minimal residual disease (MRD) could predict relapse or induction failure more precisely than current risk stratification. These results were still significant in the ALL patients without BCR-ABL fusion.\Question: Does e2F3a gene expression have prognostic significance in childhood acute lymphoblastic leukemia?
Example Output: Low expression of E2F3a was associated with inferior prognosis in childhood ALL. An algorithm composed of E2F3a expression and MRD could predict relapse or induction failure more precisely than that of the current risk stratification.

Example Input: Context: To evaluate the use of fluid-attenuated inversion recovery (FLAIR) imaging as surrogate marker of lesion age within the first 6 hours of ischemic stroke.', 'e analyzed FLAIR and diffusion-weighted imaging (DWI) sequences performed within 6 hours of symptom onset in 120 consecutive patients with ischemic stroke with known symptom onset. The visibility of acute ischemic lesions on FLAIR images was judged in two steps (on FLAIR alone and with knowledge of DWI) and compared with DWI.', 'egative FLAIR in the case of positive DWI allocated ischemic lesions to a time window 3 hours or less with a high specificity (0.93) and a high positive predictive value (0.94), whereas sensitivity (0.48) and negative predictive value (0.43) were low. Lesion visibility on FLAIR images alone (35.6%) and with knowledge of DWI (62.5%) was lower than on DWI (97.1%). The sensitivity of FLAIR increased with increasing time from symptom onset from 27.0/50.0% <or= 3 hours to 56.7/93.3% after 3 to 6 hours (FLAIR alone/with knowledge of DWI). Multivariate regression analysis spotted longer time from symptom onset and larger size of the ischemic lesion as independent predictors of lesion visibility on FLAIR images.\Question: Does negative fluid-attenuated inversion recovery imaging identify acute ischemic stroke at 3 hours or less?
Example Output:
"mismatch" between positive DWI and negative FLAIR allows the identification of patients that are highly likely to be within the 3-hour time window. Within the first 6 hours of stroke, the sensitivity of FLAIR sequences for acute ischemic lesions increases with time from symptom onset elapsing, approximating 100% after 3 to 6 hours.