Given a passage with a context and an answer, construct a question on the basis of the information present in the passage. Construct the question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) it answer uses text phrases from the passage. Avoid creating questions that (i) can't be answered correctly without actually understanding the passage and (ii) uses the same words or phrases given in the passage.

Example Input: Context: To determine whether the number and location of positive surgical margins (PSMs) in radical prostatectomy (RP) surgical specimens affect biochemical recurrence (BCR) rates.', 'The locations of PSMs were recorded for 1308 consecutive men who underwent RP between October 2000 and December 2006. BCR was defined as three consecutive prostate-specific antigen (PSA) level rises with the peak level >or=0.15 ng/mL. Multivariate regression analyses were used to identify preoperative predictors of PSMs and BCR. The estimated 5-year risk of BCR was calculated using the Kaplan-Meier method.', 'In all, 128 (9.8%) men had one or more PSMs. The mean body mass index, mean preoperative serum PSA level, the distributions of clinical stage and biopsy Gleason scores, and the presence or absence of biopsy perineural invasion were significantly different between men with or with no PSMs. In multivariate analysis, baseline serum PSA level, Gleason score and perineural invasion were independent preoperative predictors of PSMs. The 5-year actuarial BCR rates were dependent on the site of the PSM (P = 0.035) and not the number of PSMs (P = 0.18). The rank order of estimated 5-year BCR rates according to the site of PSMs were base > anterior > posterolateral > apex approximately posterior.
Answer: About half of the men with PSMs in the RP surgical specimen in our prospective series did not develop BCR. The risk of BCR was dependent on the site and not the number of PSMs. Adjuvant therapy should be considered in cases with anterior and basilar PSMs due to the very high risk of BCR.
Example Output: Does site of positive surgical margins influence biochemical recurrence after radical prostatectomy?

Example Input: Context: The purpose of this study was to examine how variation in the beta-2 adrenergic receptor gene (ADRB2), in combination with the moderating influences of race, body mass index (BMI), and anger expression style (anger-in, anger-out), affects blood pressure (BP) at rest and in response to acute laboratory stress.', 'Four hundred fifty adolescents (mean age = 18.5 +/- 2.7 years; 228 [124 males] whites and 222 [110 males] blacks completed two stressors (video game challenge, forehead cold pressor). Hemodynamic measures were taken before, during, and after each stressor. Stressors were separated by a 20-minute rest period.', 'Frequency of detrimental haplotype (Gly16/Glu27) carrier status was greater among whites than blacks (p < .05). A significant three-way interaction among haplotype, BMI, and race for resting systolic blood pressure (SBP) found the highest BP level to be among high BMI carriers, but only for whites. A separate three-way interaction was found to be significant for haplotype, anger-in and race such that high anger-in carriers showed the highest level of resting SBP (p < .05) and total peripheral resistance (TPR) (p < .05) and the greatest TPR reactivity to the cold pressor task (p < .01). Post hoc analyses revealed these interactions with anger-in were only present among blacks. No significant interactions with anger-out for either ethnic group were observed.
Answer: This study demonstrates modulating influences of BMI and anger expression styles on ADRB2 gene associations with hemodynamic function at rest and in response to laboratory stress. These findings support the hypothesis that consideration of gene-environment interactions may better characterize the role of ADRB2 variation in the development of stress-induced essential hypertension.
Example Output: Do anger suppression and adiposity modulate association between ADRB2 haplotype and cardiovascular stress reactivity?

Example Input: Context: There have been investigations on the chemopreventive effect of nonsteroidal anti-inflammatory drugs (NSAIDs) in gastric cancer and also on the association between cyclo-oxygenase 2 expression and the clinicopathological features of gastric cancer. However, it is not yet clear whether the cardioprotective properties of low-dose aspirin could affect the biological behavior of gastric cancer. This study was aimed at investigating the association between the use of low-dose aspirin and clinicopathological features of gastric cancer in human.', 'A case-control study was performed retrospectively by comparing the clinicopathological parameters between two groups of gastric cancers, 47 (30.5%) low-dose aspirin users and 107 (69.5%) non-aspirin users who were diagnosed and underwent operation for gastric cancers.', 'The gastric cancers of aspirin user group showed favorable clinicopathological features, such as earlier tumor stage (overall stage, T and N stage: p < 0.001, <0.001, and 0.002, respectively), smaller size (p = 0.03), and intestinal type rather than diffuse type (p = 0.004). But these differences were significant only in non-cardiac cancer while cardiac cancer patients showed no significant association with low-dose aspirin usage (overall stage, T stage, N stage, tumor size, and histological type: p <0.001, <0.001, 0.003, 0.035, and 0.004, respectively, by Cochran-Mantel-Haenszel statistics).
Answer: The use of low-dose aspirin might affect the clinicopathological features in gastric cancers, and possibly have a favorable protective effect on the progression of gastric cancer in a subset of non-cardiac gastric cancer patients.
Example Output:
Does low-dose aspirin affect the clinicopathological features of gastric cancer?