LETTER TO THE EDITOR Genetic Analysis of Brazilian Patients with Gallbladder Cancer Cristina Sábato 1 & Luciana Bastos-Rodrigues 2 & Debora Chaves Moraes 1 & Eitan Friedman 3,4 & Luiz De Marco 1 & Vivian Resende 1 Received: 6 January 2017 /Accepted: 7 March 2018 # Arányi Lajos Foundation 2018 To the Editor, Gallbladder cancer (GBC) is a rare neoplasm with poor prognosis and overall survival [1]. Its underlying molecular pathogenesis remains largely elusive and the accumulation of multiple somatic genetic alterations as well as chronic inflam- mation associated with gallstone formation promotes epithelial dysplasia and progression to adenocarcinoma postulated [2–4]. It has been shown that some indigenous people and ethnic groups have higher incidence and mortality rates, with differ- ences within the same country and some populations identi- fied as high-risk groups for GBC development. The highest incidence rates are found in populations living west of the Andes, northern India and populations of American and Mexican Indians [1]. The potential association in genetically heterogeneous Brazilian GBC patients has not been previously reported. Based in a comprehensive study [4] and COSMIC database ( http://cancer.sanger.ac.uk/cosmic) we investigated the contribution of TP53, KRAS, CDKN2A, PIK3CA and BRAF and ancestry component to the pathogenesis of GBC in a subset of Brazilian patients. All GBC patients who underwent surgical procedure in our Hospital (August 2011–December 2012) were eligible and signed an informed consent, a study approved by the local Ethics Committee. Clinical data were collected by a structured questionnaire. Tumor related data such as histologic type and staging were also obtained (Table 1). Genomic DNA from peripheral blood and tumor DNA were extraced using standard protocols. Tumor samples were immediately placed in tubes containing RNAlater® and stored at -80 °C. Subsequently, tumors were micro-dissected to en- sure enrichment. To enable a specific amplification of all rel- evant exons of BRAF, KRAS, P53, CDKN2A and PIK3CA genes, primers were designed (sequences available on re- quest). The PCR reaction followed protocol parameters of AmpliTaq Gold® PCR Master Mix (Thermofisher Scientific, São Paulo, Brazil). Bi-directional sequencing reac- tions were performed and analyzed. DNA from tumor tissue of GBC cases and peripheral blood DNA from 75 healthy controls were genotyped independently employing biallelic indels as described [5]. The Structure soft- ware version 2.3, (http://pritch.bsd.uchicago.edu/structure. html ) estimated the biogeographical ancestry for each individual. As parental populations, we used individuals of European, African, and Amerindian origin (http://www. cephb.fr/HGDP-CEPH-Panel). Mann-Whitney test was per- formed to compare groups. PolyPhen-2 software evaluated the impact of the amino acid substitution in protein structure ( http://genetics.bwh.harvard.mutations edu/pph2/) and PROVEAN software (http://provean.jcvi.org/index.php) indicated whether the change was deleterious. Overall 12 cases were recruited and tumor characteristics, relevant clinical and ancestry data are shown (Table 1); control group included 75 healthy individuals. Candidate genes genotyping and ancestry component are shown in Table 2. One tumor had more than one mutation. In three tumors no somatic mutations were found. Five tumors displayed CDKN2A mutations, three harbored known KRAS mutations and two presented TP53 mutations. Both patients with somatic TP53 deletions exhibited a second anatomically distinct tumor: an intrahepatic cholangiocarcinoma and a mel- anoma of the nasal mucosa. Mutations in BRAF and PIK3CA were not present. * Luiz De Marco ldemarco@ufmg.br; luiz.demarco@gmail.com 1 Department of Surgery, Universidade Federal de Minas Gerais, Av. Alfredo Balena 190, room 114, Belo Horizonte 30130-100, Brazil 2 Department of Nutrition, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil 3 The Susanne Levy Gertner Oncogenetics Unit, Chaim Sheba Medical Center, Tel-Hashomer, Israel 4 Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel Pathology & Oncology Research https://doi.org/10.1007/s12253-018-0407-7