Volatilomic profiles of gastric juice in gastric cancer patients.

Volatilomics is a powerful tool capable of providing novel biomarkers for the diagnosis of gastric cancer. The main objective of this study was to characterize the volatilomic signatures of gastric juice in order to identify potential alterations induced by gastric cancer. Gas chromatography with mass spectrometric detection, coupled with headspace solid phase microextraction as the pre-concentration technique, was used to identify volatile organic compounds (VOCs) released by gastric juice samples collected from 78 gastric cancer patients and two cohorts of controls (80 and 96 subjects) from four different locations (Latvia, Ukraine, Brazil, and Colombia). 1440 distinct compounds were identified in samples obtained from patients and 1422 in samples provided by controls. However, only 6% of the VOCs exhibited an incidence higher than 20%. Amongst the volatiles emitted, 18 showed differences in their headspace concentrations above gastric juice of cancer patients and controls. Ten of these (1-propanol, 2,3-butanedione, 2-pentanone, benzeneacetaldehyde, 3-methylbutanal, butylated hydroxytoluene, 2-pentyl-furan, 2-ethylhexanal, 2-methylpropanal and phenol) appeared at significantly higher levels in the headspace of the gastric juice samples obtained from patients; whereas, eight species showed lower abundance in patients than found in controls. Given that the difference in the volatilomic signatures can be explained by cancer-related changes in the activity of certain enzymes or pathways, the former set can be considered potential biomarkers for gastric cancer, which may assist in developing non-invasive breath tests for the diagnosis of this disease. Further studies are required to elucidate further the mechanisms that underlie the changes in the volatilomic profile as a result of gastric cancer.

ENDOSCOPIC CHARACTERISTICS OF PATIENTS WITH COMPLETE PATHOLOGICAL RESPONSE AFTER NEOADJUVANT CHEMOTHERAPY FOR GASTRIC AND ESOPHAGOGASTRIC JUNCTION ADENOCARCINOMAS.

BACKGROUND: Gastric and esophagogastric junction adenocarcinoma are responsible for approximately 13.5% of cancer-related deaths. Given the fact that these tumors are not typically detected until they are already in the advanced stages, neoadjuvancy plays a fundamental role in improving long-term survival. Identification of those with complete pathological response (pCR) after neoadjuvant chemotherapy (NAC) is a major challenge, with effects on organ preservation, extent of resection, and additional surgery. There is little or no information in the literature about which endoscopic signs should be evaluated after NAC, or even when such re-evaluation should occur. AIM: To describe the endoscopic aspects of patients with gastric and esophagogastric junction adenocarcinomas who underwent NAC and achieved pCR, and to determine the accuracy of esophagogastroduodenoscopy (EGD) in predicting the pCR. METHODS: A survey was conducted of the medical records of patients with these tumors who were submitted to gastrectomy after NAC, with anatomopathological result of pCR. RESULTS: Twenty-nine patients were identified who achieved pCR after NAC within the study period. Endoscopic responses were used to classify patients into two groups: G1-endoscopic findings consistent with pCR and G2-endoscopic findings not consistent with pCR. Endoscopic evaluation in G1 was present in an equal percentage (47.4%; p=0.28) in Borrmann classification II and III. In this group, the predominance was in the gastric body (57.9%; p=0.14), intestinal subtype with 42.1% (p=0.75), undifferentiated degree, 62.5% (p=0.78), Herb+ in 73.3% (p=0.68). The most significant finding, however, was that the time interval between NAC and EGD was longer for G1 than G2 (24.4 vs. 10.2 days, p=0.008). CONCLUSION: EGD after NAC seems to be a useful tool for predicting pCR, and it may be possible to use it to create a reliable response classification. In addition, the time interval between NAC and EGD appears to significantly influence the predictive power of endoscopy for pCR.

Endoscopic characteristics of patients with complete pathological response after neoadjuvant chemotherapy for gastric and esophagogastric junction adenocarcinomas / Características endoscópicas de pacientes com resposta patológica completa após quimioterapia neoadjuvante para adenocarcinomas gástricos e de junção esofagogástrica

ABSTRACT Background: Gastric and esophagogastric junction adenocarcinoma are responsible for approximately 13.5% of cancer-related deaths. Given the fact that these tumors are not typically detected until they are already in the advanced stages, neoadjuvancy plays a fundamental role in improving long-term survival. Identification of those with complete pathological response (pCR) after neoadjuvant chemotherapy (NAC) is a major challenge, with effects on organ preservation, extent of resection, and additional surgery. There is little or no information in the literature about which endoscopic signs should be evaluated after NAC, or even when such re-evaluation should occur. Aim: To describe the endoscopic aspects of patients with gastric and esophagogastric junction adenocarcinomas who underwent NAC and achieved pCR, and to determine the accuracy of esophagogastroduodenoscopy (EGD) in predicting the pCR. Methods: A survey was conducted of the medical records of patients with these tumors who were submitted to gastrectomy after NAC, with anatomopathological result of pCR. Results: Twenty-nine patients were identified who achieved pCR after NAC within the study period. Endoscopic responses were used to classify patients into two groups: G1-endoscopic findings consistent with pCR and G2-endoscopic findings not consistent with pCR. Endoscopic evaluation in G1 was present in an equal percentage (47.4%; p=0.28) in Borrmann classification II and III. In this group, the predominance was in the gastric body (57.9%; p=0.14), intestinal subtype with 42.1% (p=0.75), undifferentiated degree, 62.5% (p=0.78), Herb+ in 73.3% (p=0.68). The most significant finding, however, was that the time interval between NAC and EGD was longer for G1 than G2 (24.4 vs. 10.2 days, p=0.008). Conclusion: EGD after NAC seems to be a useful tool for predicting pCR, and it may be possible to use it to create a reliable response classification. In addition, the time interval between NAC and EGD appears to significantly influence the predictive power of endoscopy for pCR.

RESUMO Racional: O adenocarcinoma gástrico e da junção esofagogástrica é responsável por aproximadamente 13,5% das mortes relacionadas ao câncer. Dado que esses tumores não são normalmente detectados até que já estejam em estágios avançados, a neoadjuvância desempenha um papel fundamental na melhoria da sobrevida em longo prazo. A identificação daqueles com resposta patológica completa (pCR) após a quimioterapia neoadjuvante (NAC) é um grande desafio, com efeitos na preservação do órgão, extensão da ressecção e cirurgia adicional. Há pouca ou nenhuma informação na literatura sobre quais sinais endoscópicos devem ser avaliados após a NAC, ou mesmo quando essa reavaliação deve ocorrer. Objetivo: Descrever os aspectos endoscópicos de pacientes com adenocarcinoma gástrico e da junção esofagogástrica que foram submetidos à quimioterapia neoadjuvante e alcançaram pCR, e determinar a acurácia da esofagogastroduodenoscopia (EGD) em predizer a pCR. Métodos: Foram revisados os prontuários de pacientes submetidos à gastrectomia subtotal e total após NAC, com resultado anatomopatológico de pCR. Resultados: Vinte e nove pacientes que alcançaram pCR após NAC foram identificados no período estudado. As respostas endoscópicas foram usadas para classificar os pacientes em dois grupos: G1- achados endoscópicos consistentes com pCR, G2 - achados endoscópicos não consistentes com pCR. A avaliação endoscópica no G1 esteve presente em igual percentual (47,4%; p=0,28) na classificação de Borrmann II e III. Nesse grupo, a predominância foi no corpo gástrico (57,9%; p=0,14), subtipo intestinal com 42,1% (p=0,75), grau indiferenciado, 62,5% (p=0,78), Herb+ em 73,3% (p=0,68). O achado mais significativo, no entanto, foi que o intervalo de tempo entre NAC e EGD foi maior para G1 do que G2 (24,4 vs. 10,2 dias, p=0,008). Conclusão: A EGD após NAC, nessa pesquisa, sugeriu ser método útil para prever pCR, mediante uma classificação de resposta confiável. Além disso, o intervalo de tempo entre NAC e EGD parece influenciar significativamente a sua capacidade preditiva de diagnosticar a pCR.

Identification of DNA mutations in gastric washes from gastric adenocarcinoma patients: Possible implications for liquid biopsies and patient follow-up.

Whereas cancer patients have benefited from liquid biopsies, the scenario for gastric adenocarcinoma (GAC) is still dismal. We used next-generation deep sequencing of TP53-a highly mutated and informative gene in GAC-to assess mutations in tumor biopsies, plasma (PL) and stomach fluids (gastric wash-GW). We evaluated their potential to reveal tumor-derived mutations, useful for monitoring mutational dynamics at diagnosis, progression and treatment. Exon-capture libraries were constructed from 46 patients including tumor biopsies, GW and PL pre and post-treatment (196 samples), with high vertical coverage >8,000×. At diagnosis, we detected TP53 mutations in 15/46 biopsies (32.6%), 7/46 GW- (15.2%) and 6/46 PL-samples (13%). Biopsies and GW were concordant in 38/46 cases (82.6%) for the presence/absence of mutations and, furthermore, four GW-exclusive mutations were identified, suggesting tumor heterogeneity. Considering the combined analysis of GW and PL, TP53 mutations found in biopsies were also identified in 9/15 (60%) of cases, the highest detection level reported for GAC. Our study indicates that GW could be useful to track DNA alterations, especially if anchored to a comprehensive gene-panel designed for this malignancy.

Alternative technique in secondary tracheoesophageal puncture using flexible endoscope and overtube in patients with difficult post-laryngectomy abnormalities

Background: Functional speech rehabilitation after total laryngectomy remains one of the most challenging issues in head and neck multidisciplinary care. Tracheoesophageal puncture for voice prosthesis insertion performed as a secondary procedure with a rigid esophagoscope and trocar can be technically difficult in certain patients due to post-treatment cervical abnormalities, such as reduced hyperextension, stenosis, and trismus. Methods: This study presents an improved method of secondary tracheoesophageal prosthesis insertion using a flexible endoscope in association with a plastic pliable overtube to keep the virtual esophageal lumen open. By this method, the puncture can be performed easily and safely with the avoidance of unexpected lesions. Results: From 2005 to 2015, 12 (16,9%) out of 71 patients who underwent secondary voice prosthesis placement at our institution required this alternative technique due to anatomical alterations that hindered the execution of the procedure following the standard technique. Conclusion: The procedure was successfully performed in all patients with no related complications (AU)