Quality Assessment of Cryopreserved Human Biological Samples from the Biobank of Barretos Cancer Hospital.

Background: Biobanks process, store, and supply biological materials for research. Preanalytical factors, especially storage time and temperature, must be controlled and standardized at all stages when handling biospecimen samples, especially because the literature reports highly contradictory optimal parameters. As large-sample studies are required to better understand the influence of time and temperature on cryopreserved samples' quality for genomic research, this study evaluated the integrity and quality of cryopreserved samples stored for up to 9 years at the biobank of Barretos Cancer Hospital, one of the largest biobanks in Latin America. Methods: We randomly selected 447 samples with tumor tissue paired with buffy coat or peripheral blood mononuclear cells (PBMCs) that were stored from 2008 to 2016. The genetic material quality was evaluated based on RNA integrity (RIN) and DNA integrity (DIN) ≥7, which indicated undegraded samples, and compared with storage time, which means that for DNA storage time, samples <8.1 and ≥8.1 years and for RNA <4.5 and ≥4.5 were used. Results: A total of 190 tumor tissues were eligible for DNA and RNA extraction. Those stored for 8 years had lower DIN (68%) than those stored for a shorter period (92%). A similar pattern, based on storage time (<8.1 and ≥8.1 years), was observed in the buffy coat (74% and 95%, respectively) and PBMCs (54% and 96%, respectively). For RNA extracted from tumor tissues, we observed lower RIN in samples stored for 4.5 years (17%) than in samples stored for a shorter period (45%). Buffy coat and PBMC samples stored at -30°C exhibited greater degradation (26%) than those stored at -80°C (1%). The DIN (p = 0.15) and RNA (p = 0.18) were unrelated to topography type. Conclusion: The temperature, particularly cryopreservation methodology, and storage time were the main factors that affected nucleic acid integrity, especially RNA, during cryopreservation of biospecimens.

Reproduction of the Cancer Genome Atlas (TCGA) and Asian Cancer Research Group (ACRG) Gastric Cancer Molecular Classifications and Their Association with Clinicopathological Characteristics and Overall Survival in Moroccan Patients.

INTRODUCTION: The Cancer Genome Atlas (TCGA) project and Asian Cancer Research Group (ACRG) recently categorized gastric cancer into molecular subtypes. Nevertheless, these classification systems require high cost and sophisticated molecular technologies, preventing their widespread use in the clinic. This study is aimed to generating molecular subtypes of gastric cancer using techniques available in routine diagnostic practice in a series of Moroccan gastric cancer patients. In addition, we assessed the associations between molecular subtypes, clinicopathological features, and prognosis. METHODS: Ninety-seven gastric cancer cases were classified according to TCGA, ACRG, and integrated classifications using a panel of four molecular markers (EBV, MSI, E-cadherin, and p53). HER2 status and PD-L1 expression were also evaluated. These markers were analyzed using immunohistochemistry (E-cadherin, p53, HER2, and PD-L1), in situ hybridization (EBV and HER2 equivocal cases), and multiplex PCR (MSI). RESULTS: Our results showed that the subtypes presented distinct clinicopathological features and prognosis. EBV-positive gastric cancers were found exclusively in male patients. The GS (TCGA classification), MSS/EMT (ACRG classification), and E-cadherin aberrant subtype (integrated classification) presented the Lauren diffuse histology enrichment and tended to be diagnosed at a younger age. The MSI subtype was associated with a better overall survival across all classifications (TCGA, ACRG, and integrated classification). The worst prognosis was observed in the EBV subtype (TCGA and integrated classification) and MSS/EMT subtype (ACRG classification). Discussion/Conclusion. We reported a reproducible and affordable gastric cancer subtyping algorithms that can reproduce the recently recognized TCGA, ACRG, and integrated gastric cancer classifications, using techniques available in routine diagnosis. These simplified classifications can be employed not only for molecular classification but also in predicting the prognosis of gastric cancer patients.

Survivin as a predictive biomarker of complete pathologic response to neoadjuvant chemotherapy in patients with stage II and stage III breast cancer.

INTRODUCTION: Predictive biomarkers of response to neoadjuvant chemotherapy in patients with breast cancer are needed to better characterize tumors and enable more tailored therapies. METHODS: The expression levels of survivin, BCL-2, cyclin D1, ETS1, and PDEF in tumor samples obtained in the diagnostic biopsies of patients undergoing neoadjuvant chemotherapy for stage II and stage III disease were evaluated by immunohistochemistry (IHC). The mean expression score (range, 0-15) obtained by 3 different pathologists was used for analysis and correlated with complete pathologic response (pCR) and survival by standard univariate and multivariate methods. RESULTS: Forty-five female patients were included in this study and received preoperative standard anthracycline/taxane-based chemotherapy. The median age at diagnosis was 49 years (range, 25-70 years). Three patients (7.1%) achieved pCR. The mean expression score of survivin in the diagnostic biopsies was significantly higher (P = .01) in patients with pCR (9.3) than in those without (3.4). There was no significant association with pCR for the other biologic markers analyzed nor was there correlation with prognosis. Survivin levels were not associated with age, tumor grade, clinical stage, or receptor status. CONCLUSION: High expression levels of survivin in the primary tumor may be used as a potential predictive biomarker of pCR to neoadjuvant chemotherapy in patients with stage II and stage III breast cancer.

Histological behavior of hepatic steatosis in morbidly obese patients after weight loss induced by bariatric surgery.

BACKGROUND: Hepatic steatosis has a high prevalence among morbidly obese patients. Its relation to steatohepatitis and cirrhosis has been extensively studied among these patients. The aim of this study was to evaluate the behavior of hepatic steatosis with weight loss 1 year after bariatric surgery. METHODS: This study is a historical cohort that compared liver biopsies obtained from morbidly obese patients during the bariatric operation, with percutaneous biopsies taken from the same patient 1 year after surgery. The results were compared with weight loss, patients' profile (gender, age, body mass index (BMI) and waist/hip ratio), and with the presence of co-morbidities such as diabetes, hypertension, and dyslipidemia. RESULTS: 90 patients who had liver biopsies taken at the operation and postoperative period for bariatric surgery were included. The prevalence of hepatic steatosis was 87.6%. The average percent of excess weight loss was 81.4%. On the second biopsy, 16 patients (17.8%) of the total had the same degree of steatosis, 25 (27.8%) improved their steatosis pattern and 49 (54.4%) had normal hepatic tissue. There was no statistical difference regarding age, BMI, waist/hip ratio, and co-morbidities (P>0.05), but there was a difference in gender (P=0.044). CONCLUSION: Significant improvement in the hepatic histology of steatosis was observed after weight loss induced by bariatric surgery in most patients. There was no patient with a worsening in the histology.