Given a passage, 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: Ductal carcinoma in situ with microinvasion (DCISM) is a rare diagnosis with a good prognosis. Although nodal metastases are uncommon, sentinel lymph node biopsy (SLNB) remains standard care. Volume of disease in invasive breast cancer is associated with SLNB positivity, and, thus we hypothesized that in a large cohort of patients with DCISM, multiple foci of microinvasion might be associated with a higher risk of positive SLNB.', 'Records from a prospective institutional database were reviewed to identify patients with DCISM who underwent SLNB between June 1997 and December 2010. Pathology reports were reviewed for number of microinvasive foci and categorized as 1 focus or ≥2 foci. Demographic, pathologic, treatment, and outcome data were obtained and analyzed.', 'Of 414 patients, 235 (57 %) had 1 focus of microinvasion and 179 (43 %) had ≥2 foci. SLNB macrometastases were found in 1.4 %, and micrometastases were found in 6.3 %; neither were significantly different between patients with 1 focus versus ≥2 foci (p = 1.0). Patients with positive SLNB or ≥2 foci of microinvasion were more likely to receive chemotherapy. At median 4.9 years (range 0-16.2 years) follow-up, 18 patients, all in the SLNB negative group, had recurred for an overall 5-year recurrence-free proportion of 95.9 %.
Example Output: Is extent of microinvasion in ductal carcinoma in situ associated with sentinel lymph node metastases?

Example Input: Glutathione S-transferases (GSTs) are involved in the metabolism of carcinogens and anticancer drugs. Functional polymorphisms exist in at least three genes that code for the GSTs, such as the GSTM1 and GSTT1 gene deletions or the A-G transition within the GSTP1 gene, which represents distinct GSTP1a and GSTP1b alleles. In the present case-control study, we aimed at estimation of the relationship between the GSTM1, GSTT1, and GSTP1 genotypes and the susceptibility to various types of childhood malignancies and the early relapses of diseases.', 'Using the polymerase chain reaction on the DNA extracted from peripheral blood leukocytes, we identified the GSTM1, GSTT1, and GSTP1 genotypes in 234 children at the initial stage of a childhood malignancy as well as in 460 age-and sex-matched healthy subjects who served as controls. The follow-up period for the effects of the anticancer therapy ranged from 11 to 43 months.', 'Compared to the controls, a significant increase in the frequency of the GSTP1b/GSTP1b genotype (odds ratio (OR) 5.7; 95% confidence limit (CL) from 2.4 to 13.8; Pearsons Chi-square P = 0.0001) was detected in the children with neoplasms. The GSTM1 and GSTT1 genotypes did not show any correlation with the risk of the de novo diagnosed neoplasms. During the observation, 62 children (26%) were found to be present with a local or disseminated recurrence of the diseases. The analysis indicated a trend in increasing risk of relapse for carriers of the GSTP1a allele (OR = 3.29; 95% CL from 0.73 to 14.67 P = 0.03).
Example Output: Is polymorphism within the glutathione S-transferase P1 gene associated with increased susceptibility to childhood malignant diseases?

Example Input: Increased blood flow velocity in the contralateral vertebral artery (VA) is a common finding in subclavian steal syndrome, but its clinical relevance is not known. The aim of this study was to investigate whether the degree of velocity increase in the contralateral VA correlated with the severity of the steal.', 'In a retrospective study of 62 patients with subclavian steal phenomenon and 62 sex- and age-matched controls, we analyzed the peak systolic velocity (PSV), end diastolic velocity (EDV), mean velocity (MV), resistance index (RI), and pulsatility index (PI) of the Doppler spectrum of the VA contralateral to the subclavian steal phenomenon. Clinical information including sex, age, comorbidities and Doppler data were recorded from the sonography registration form.', 'In patients with subclavian steal syndrome, Doppler spectral analysis showed a complete reversal of flow in the VA in 29 patients (group A) and an alternating flow in 33 patients (group B). The PSV, MV, RI, and PI of the contralateral VA of patients from both groups were higher than in controls (p < 0.01 for both comparisons). The PSV, EDV, and MV in the contralateral VA were higher in patients with reversed flow compared with those with alternating flow (p < 0.05). Comparisons of clinical symptoms and comorbidities between the two groups did not yield significant findings.
Example Output:
Do hemodynamic effects of subclavian steal phenomenon on contralateral vertebral artery?