instruction:
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.
question:
Cadherins are calcium-dependent cell-to-cell adhesion glycoproteins playing a critical role in the formation and maintenance of normal tissue architecture. In normal mammary gland, E-cadherin is expressed by luminal epithelial cells, while P-cadherin is restricted to myoepithelial cells. Changes in the expression of classical E- and P-cadherins have been observed in mammary lesions and related to mammary carcinogenesis. P-cadherin and E-cadherin expressions were studied in a series of feline normal mammary glands, hyperplastic/dysplastic lesions, benign and malignant tumours by immunohistochemistry and double-label immunofluorescence.', 'In normal tissue and in the majority of hyperplastic/dysplastic lesions and benign tumours, P-cadherin was restricted to myoepithelial cells, while 80% of the malignant tumours expressed P-cadherin in luminal epithelial cells. P-cadherin expression was significantly related to high histological grade of carcinomas (p <0.0001), tumour necrosis (p = 0.001), infiltrative growth (p = 0.0051), and presence of neoplastic emboli (p = 0.0401). Moreover, P-cadherin positive carcinomas had an eightfold likelihood of developing neoplastic emboli than negative tumours. Cadherins expression profile in high grade and in infiltrative tumours was similar, the majority expressing P-cadherin, regardless of E-cadherin expression status. The two cadherins were found to be co-expressed in carcinomas with aberrant P-cadherin expression and preserved E-cadherin.
answer:
Is aberrant P-cadherin expression associated to aggressive feline mammary carcinomas?

question:
The age gap between participants in trials and patients who could benefit from the drugs studied has been widely documented across different clinical areas. Patients with dementia included in clinical research are systematically younger than those in the general population. We examined the age gap between participants in recent clinical trials testing interventions for Alzheimer's disease and epidemiological data.", "We systematically searched literature databases (MedLine, EMBASE, the Cochrane Library) and ClinicalTrials.gov from 2000 to July 2015 to retrieve clinical trials testing pharmacologic treatments for Alzheimer's disease, other than cholinesterase inhibitors and memantine. We included ongoing and completed phase II/III randomized clinical trials, irrespective of their publication status. From each study reporting the participants' ages, we extracted size of sample, mean age, and standard deviation, and estimated the proportions of participants in different age classes. The number of patients with Alzheimer's disease by age class in the USA population was used for comparison.", "We included 165 clinical trials testing almost 100 different compounds, which enrolled or planned to enroll about 74,300 participants. Seventy-nine of these trials, accounting for about 26,800 participants, reported the age of the participants. The weighted mean age was 73.6 years (standard deviation, 8.2). People younger than 80 years were highly represented in clinical trials (78 %), despite the fact that those aged 80 and older form the majority (72 %) of patients with Alzheimer's disease. Only 8 % of clinical trial participants were 85 years or older.
answer:
Are older patients still under-represented in clinical trials of Alzheimer 's disease?

question:
The aim of this study was to compare the clinical outcome of percutaneous radiofrequency (RF) ablation, conventional percutaneous ethanol injection (PEI), and higher-dose PEI in treating hepatocellular carcinoma (HCC) 4 cm or less.', 'A total of 157 patients with 186 HCCs 4 cm or less were randomly assigned to 3 groups (52 patients in the conventional PEI group, 53 in the higher-dose PEI group, and 52 in the RF group). Clinical outcomes in terms of complete tumor necrosis, overall survival, local tumor progression, additional new tumors, and cancer-free survival were compared across 3 groups.', 'The rate of complete tumor necrosis was 88% in the conventional PEI group, 92% in the higher-dose PEI group, and 96% in the RF group. Significantly fewer sessions were required to achieve complete tumor necrosis in the RF group than in the other 2 groups (P < .01). The local tumor progression rate was lowest in the RF group (vs the conventional PEI group, P = .012; vs the higher-dose PEI group, P = .037). The overall survival rate was highest in the RF group (vs the conventional PEI group, P = .014; vs the higher-dose PEI group, P = .023). The cancer-free survival rate was highest in the RF group (vs the conventional PEI group, P = .019; vs the higher-dose PEI group, P = .024). Multivariate analysis determined that tumor size, tumor differentiation, and the method of treatment (RF vs both methods of PEI) were significant factors in relation to local tumor progression, overall survival, and cancer-free survival.
answer:
Does radiofrequency ablation improve prognosis compared with ethanol injection for hepatocellular carcinoma < or =4 cm?