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1570 Background: Analysis of exhaled volatile organic compounds (VOCs) in breath is an emerging approach for cancer diagnosis, but little is known about its potential use as a biomarker for colorectal cancer (CRC). We investigated whether a combination of VOCs could distinct CRC patients from healthy volunteers. Methods: In a pilot study, we prospectively analyzed breath exhalations of 38 CRC patient and 43 healthy controls all scheduled for colonoscopy, older than 50 in the average-risk category. The samples were ionized and analyzed using a Secondary ElectroSpray Ionization (SESI) coupled with a Time-of-Flight Mass Spectrometer (SESI-MS). After a minimum of 2 hours fasting, volunteers deeply exhaled into the system. Each test requires three soft exhalations and takes less than ten minutes. No breath condensate or collection are required and VOCs masses are detected in real time, also allowing for a spirometric profile to be analyzed along with the VOCs. A new sampling system precludes ambient air from entering the system, so background contamination is reduced by an overall factor of ten. Potential confounding variables from the patient or the environment that could interfere with results were analyzed. Results: 255 VOCs, with masses ranging from 30 to 431 Dalton have been identified in the exhaled breath. Using a classification technique based on the ROC curve for each VOC, a set of 9 biomarkers discriminating the presence of CRC from healthy volunteers was obtained, showing an average recognition rate of 81.94%, a sensitivity of 87.04% and specificity of 76.85%. Conclusions: A combination of cualitative and cuantitative analysis of VOCs in the exhaled breath could be a powerful diagnostic tool for average-risk CRC population. These results should be taken with precaution, as many endogenous or exogenous contaminants could interfere as confounding variables. On-line analysis with SESI-MS is less time-consuming and doesn’t need sample preparation. We are recruiting in a new pilot study including breath cleaning procedures and spirometric analysis incorporated into the postprocessing algorithms, to better control for confounding variables.

Changes in magnetic resonance imaging (MRI) during neoadjuvant chemotherapy (NAC) have been reported as predictive of pathology outcome in triple-negative and HER2-positive breast cancer. The purpose of our study was to evaluate the relevance of breast cancer subtype for MRI response in 24 women before and during NAC in our centre. Our results show that a reduction greater than 23% is associated with a pathological complete response (pCR) in Her-2-positive and ER-negative/Her2-negative breast cancer, and suggest a trend correlation between higher ADC values and pCR in these subtypes in comparison with ER-positive/Her2-negative breast cancers. Higher proliferating tumours respond better to chemotherapy and our study suggests that changes in MRI during NAC are predictive of pCR in these breast cancer subtypes.

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in both class 2 and 3 BRAF mutations. Conclusion: It is evident that different classes of BRAF mutations require distinct treatments, which could even outweigh tumor type. Therefore, we should examine BRAF class in daily clinical practice. Upfront targeting of the MAPK signaling pathway combined with SHP2 inhibitors reveals synergistic interactions, and additional inquisition may pave the way for new treatment options in the most frequently found mutations in BRAF patients.