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.

Context: With the advent of new and more efficient anti-androgen drugs targeting androgen receptor (AR) in breast cancer (BC) is becoming an increasingly important area of investigation. This would potentially be most useful in triple negative BC (TNBC), where better therapies are still needed. The assessment of AR status is generally performed on the primary tumor even if the tumor has already metastasized. Very little is known regarding discrepancies of AR status during tumor progression. To determine the prevalence of AR positivity, with emphasis on TNBCs, and to investigate AR status during tumor progression, we evaluated a large series of primary BCs and matching metastases and recurrences.', 'AR status was performed on 356 primary BCs, 135 matching metastases, and 12 recurrences using a next-generation Tissue Microarray (ngTMA). A commercially available AR antibody was used to determine AR-status by immunohistochemistry. AR positivity was defined as any nuclear staining in tumor cells ≥1 %. AR expression was correlated with pathological tumor features of the primary tumor. Additionally, the concordance rate of AR expression between the different tumor sites was determined.', 'AR status was positive in: 87 % (307/353) of primary tumors, 86.1 % (105/122) of metastases, and in 66.7 % (8/12) of recurrences. TNBC tested positive in 11.4 %, (4/35) of BCs. A discrepant result was seen in 4.3 % (5/117) of primary BC and matching lymph node (LN) metastases. Three AR negative primary BCs were positive in the matching LN metastasis, representing 17.6 % of all negative BCs with lymph node metastases (3/17). Two AR positive primary BCs were negative in the matching LN metastasis, representing 2.0 % of all AR positive BCs with LN metastases (2/100). No discrepancies were seen between primary BC and distant metastases or recurrence (n\u2009=\u200917).\Question: Is androgen receptor status highly conserved during tumor progression of breast cancer?
Most primary (87 %) and metastasized (86.1 %) BCs are AR positive including a significant fraction of TNBCs (11.4 %). Further, AR status is highly conserved during tumor progression and a change only occurs in a small fraction (4.1 %). Our study supports the notion that targeting AR could be effective for many BC patients and that re-testing of AR status in formerly negative or mixed type BC's is recommended.

Context: Centrifuge training, while an integral component in pilot training, is not without risks. To date there has never been a reported case of isolated transverse process fractures associated with centrifuge training.', 'A 32-yr-old Flight Surgeon underwent centrifuge training as part of an educational course. She had increasing back pain after exposure to the centrifuge. Follow-up studies showed left L2 and bilateral L3 transverse process fractures. No other contributory causes could be identified except for mild vitamin D deficiency.\Question: Do a Report of Transverse Process Fractures Secondary to the Centrifuge in a Healthy Aviator?
The etiology, incidence, and treatment of transverse process fractures are examined to better prepare the clinician for the management of these cases. Puderbaugh MA. A report of transverse process fractures secondary to the centrifuge in a healthy aviator. Aerosp Med Hum Perform. 2016; 87(7):655-658.

Context: Current clinical tools to identify lacunar infarct patients at risk of deterioration are inadequate, and imaging techniques to predict fluctuation and deterioration would be of value. We sought to determine the occurrence of MRI perfusion-weighted imaging (PWI) abnormalities in lacunes, and whether they help predict clinical and radiological outcome.', 'Patients with lacunar stroke or TIA were selected from a prospective MR imaging study. MRI was performed within 24 h of the event and follow-up imaging completed at 30 or 90 days. Baseline perfusion maps were qualitatively assessed and infarct volumes measured. Early clinical deterioration (NIHSS worsening of > or = 3 points within 72 h of event) and 90-day modified Rankin Scale score (mRS) were recorded.', 'Twenty-two patients were included. Fifteen (68.2%) had abnormal PWI at the site of the diffusion-weighted imaging lesion. Patients with abnormal PWI were more likely to have stroke than TIA as their index event (RR 2.2, 95% CI 0.9-5.2, p = 0.02). Early clinical deterioration occurred in 4 patients (18.2%), all of whom had abnormal PWI. PWI lesions were not associated with a higher 90-day NIHSS or mRS score, nor did they predict infarct volume growth.\Question: Does normal magnetic resonance perfusion-weighted imaging in lacunar infarcts predict a low risk of early deterioration?

MR-PWI abnormalities are seen in two thirds of lacunar infarcts, and are associated with stroke rather than TIA. Normal PWI identifies patients at low risk of early clinical deterioration.