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.

Context: Is a perioperative metastatic screening programme indicated in patients presenting with primary operable breast cancer and no signs of distant metastases?', 'The impact of staging results (chest X-ray, bone scanning, liver ultrasound) for prognosis, treatment, quality of life and costs was retrospectively analysed in 1 076 patients with an operable breast cancer and no clinical signs of metastases.', 'Staging examinations revealed 30 (2.8 %) distant metastases, 130 (12.1 %) suspect findings and excluded metastases in 916 (85.1 %) patients. Further diagnostic procedures confirmed distant metastases in 7 (5.4 %) and excluded them in 123 (94.6 %) out of 130 patients with suspect findings. Distant metastases were detected more frequently with increasing tumor size (pT < or = 2.0 cm: 1.6 %, pT 2.1-5.0 cm: 3.0 %, respectively pT > 5.0 cm: 15.1 %; p < 0.001) and increasing number of involved axillary lymph nodes (pN0: 1.4 %, pN1-3 +: 1.8 %, pN4-9 +: 4.0 %, pN > 10 +: 12.5 %; p < 0.001). Due to false positive findings 123 (11.4 %) patients had to live for a significant period of time with the psychological distress of suspected metastatic disease. The abandonment of a perioperative screening in 1 076 patients saves costs of at least euro 259,366.68.
Answer: In breast cancer patients without clinical signs of tumor spread perioperative screening for metastases is not warranted because of low frequency of metastases, false positive findings, missing therapeutic consequences and high costs.
Is [ A perioperative screening for metastatic disease indicated in patients with primary breast cancer and no clinical signs of tumor spread ]?

Context: The mechanism involved in AD is complex, which has prompted to develop compounds that could simultaneously interact with several potential targets. Here, we report a new synthesized compound SCR-1693 which is designed to target both AChE and calcium channels that are potential for AD therapy.', 'We investigated the effects of SCR-1693 on AChE and calcium channels, the effects of neuroprotection and anti-amnesia in icv-A25-35-injected mice, and the potential mechanisms.', 'AChE activity assay, intracellular Ca(2+) content and calcium currents measurement, and A25-35-induced cellular death determine were performed for validation of designed targets and neuroprotection of SCR-1693. Mice were orally administrated with SCR-1693 once daily after an A25-35 injection. The Morris water maze and Y-maze test, and hippocampal protein detection were conducted on days 5-10, day 11, and day 8. The pyramidal neuron number, hippocampal AChE activity, and synaptic transmission were measured on day 12.', 'SCR-1693 acted as a selective, reversible, and noncompetitive inhibitor of AChE, and a nonselective voltage-gated calcium channel blocker. SCR-1693 also inhibited the increase of AChE activity in the mouse hippocampus. SCR-1693 was more effective than donepezil and memantine in preventing A25-35-induced long-term and short-term memory impairment, maintaining the basal transmission of Schaffer collateral-CA1 synapses, and sustaining LTP in mouse hippocampus. SCR-1693 attenuated A25-35-induced death of SH-SY5Y cell and the loss of hippocampal pyramidal neurons, and regulated A25-35-induced signal cascade in neurons.
Answer: All these findings indicated that SCR-1693, as a double-target-direction agent, is a considerable candidate for AD therapy.
Does a novel acetylcholinesterase inhibitor and calcium channel blocker SCR-1693 improve A25-35-impaired mouse cognitive function?

Context: Clinical trials of adjuvant radiotherapy after mastectomy have largely excluded women aged 70 years or over, even though they comprise 30% of the breast cancer population. This study examined outcomes in elderly women with high-risk breast cancer treated with or without postmastectomy radiotherapy (PMRT).', 'Data were analysed for 233 women aged 70 years or over with high-risk breast cancer (tumours > 5 cm or > or = 4 positive axillary nodes) treated with mastectomy and referred to the British Columbia Cancer Agency from 1989 to 1997. Tumour and treatment characteristics were compared between two cohorts: women treated with PMRT (n = 147) vs women treated without PMRT (n = 86). Univariate and multivariate analyses of 10-year Kaplan-Meier locoregional recurrence (LRR), distant recurrence, breast cancer-specific survival and overall survival were carried out.', 'Median follow-up time was 5.5 years. The distribution of tumour sizes was similar in the two groups. Compared with women treated without PMRT, higher proportions of women who underwent PMRT had four or more positive nodes (83% vs 67%, P = 0.01) and positive surgical margins (14% vs 4%, P = 0.02). Systemic therapy, used in 94% of women, was comparable in the two cohorts (P = 0.63). Elderly women treated with PMRT had significantly lower LRR compared with women treated without PMRT (16% vs 28%, P = 0.03). No differences in distant recurrence, breast cancer-specific survival or overall survival were observed in the two treatment groups (all P > 0.05). On multivariate analysis, the omission of PMRT and the presence of high-grade histology were significant predictors of LRR, whereas an increasing number of positive nodes was significantly associated with distant recurrence and overall survival.
Answer: In women aged 70 years or over with tumours greater than 5 cm or four or more positive nodes, significantly lower LRR was observed in women treated with radiotherapy compared with women treated without radiotherapy. PMRT should be considered in the management of elderly women with these high-risk characteristics.
Does postmastectomy radiotherapy reduce locoregional recurrence in elderly women with high-risk breast cancer?