Brazilian Society of Surgical Oncology recommendations on Merkel cell carcinoma surgical treatment.

BACKGROUND: Merkel cell carcinoma (MCC) is a rare neuroendocrine skin cancer with poor 5-year survival rates. Surgery and radiation are the current first-line treatments for local and nodal disease. OBJECTIVES: The Brazilian Society of Surgical Oncology developed this document aiming to guide the surgical oncology role in multimodal MCC management. METHODS: The consensus was established in three rounds of online discussion, achieving consensus on specific topics including diagnosis, staging, treatment, and follow-up. RESULTS: Patients suspected of having MCC should undergo immunohistochemical examination and preferably undergo pathology review by a dermatopathologist. Initial staging should be performed with dermatologic and nodal physical examination, combined with complementary imaging. Whole-body imaging, preferably with positron emission tomography (PET) or computed tomography (CT) scans, are recommended. Due to the need for multidisciplinary approaches, we recommend that all cases should be discussed in tumor boards and referred to other specialties as soon as possible, reducing potential treatment delays. We recommend that all patients with clinical stage I or II may undergo local excision associated with sentinel lymph node biopsy. The decision on margin size should consider time to recovery, patient's comorbidities, and risk factors. Patients with positive sentinel lymph nodes or the presence of risk factors should undergo postoperative radiation therapy at the primary site. Exclusive radiation is a viable option for patients with low performance. Patients with positive sentinel lymph node biopsy should undergo nodal radiation therapy or lymphadenectomy. In patients with nodal clinical disease, in addition to primary tumor treatment, nodal radiation therapy and/or lymphadenectomy are recommended. Patients with advanced disease should preferably be enrolled in clinical trials and discussed in multidisciplinary meetings. The role of surgery and radiation therapy in the metastatic/advanced setting should be discussed individually and always in tumor boards. CONCLUSION: This document aims to standardize a protocol for initial assessment and treatment for Merkel cell carcinoma, optimizing oncologic outcomes in middle-income countries such as Brazil.

TNFRSF1B Gene Variants in Clinicopathological Aspects and Prognosis of Patients with Cutaneous Melanoma.

Regulatory T lymphocytes play a critical role in immune regulation and are involved in the aberrant cell elimination by facilitating tumor necrosis factor connection to the TNFR2 receptor, encoded by the TNFRSF1B polymorphic gene. We aimed to examine the effects of single nucleotide variants TNFRSF1B c.587T>G, c.*188A>G, c.*215C>T, and c.*922C>T on the clinicopathological characteristics and survival of cutaneous melanoma (CM) patients. Patients were genotyped using RT-PCR. TNFRSF1B levels were measured using qPCR. Luciferase reporter assay evaluated the interaction of miR-96 and miR-1271 with the 3'-UTR of TNFRSF1B. The c.587TT genotype was more common in patients younger than 54 years old than in older patients. Patients with c.*922CT or TT, c.587TG or GG + c.*922CT or TT genotypes, as well as those with the haplotype TATT, presented a higher risk of tumor progression and death due to the disease effects. Individuals with the c.*922TT genotype had a higher TNFRSF1B expression than those with the CC genotype. miR-1271 had less efficient binding with the 3'-UTR of the T allele when compared with the C allele of the SNV c.*922C>T. Our findings, for the first time, demonstrate that TNFRSF1B c.587T>G and c.*922C>T variants can serve as independent prognostic factors in CM patients.

Smoking cessation knowledge and perceptions of cancer care providers at six Latin American cancer institutions.

Objective: To assess the characteristics, self-reported tobacco use, knowledge, and perceptions about smoking cessation among cancer care providers (CCPs), as well as perceived barriers to inform interventions that can potentially improve quitting rates and the prognosis of cancer patients in Latin America. Methods: A cross-sectional study was conducted among 996 CCPs in six cancer institutions located in Argentina, Brazil, Colombia, Mexico, and Peru. An online survey consisting of 28 close-ended questions adapted from the 2012 International Association for the Study of Lung Cancer survey and the Global Adult Tobacco Survey was administered. Results: The majority of CCPs, ranging from 86.1% in Mexico to 95.9% in Brazil, agreed or strongly agreed that smoking cessation should be integrated into cancer treatment. However, inadequate training on smoking cessation was reported by 66.9%, 69.4%, 70.4%, 72.9%, 85.8%, and 86.4% in Mexico, Colombia (Floridablanca), Argentina, Peru, Brazil, and Colombia (Medellín), respectively, and this difference was statistically significant (p < 0.001). Moreover, current cigarette smoking prevalence among CCPs was 2.5% in Brazil, 4.6% in Peru, 6.3% in Colombia (Floridablanca), 10.4% in Colombia (Medellín), 11.5% in Mexico, and 15.1% in Argentina, showing a statistically significant difference (p < 0.001). Conclusions: Efforts in Latin America should be geared toward assisting CCPs with their quitting efforts and training in smoking cessation practices aimed at achieving a better prognosis and improving cancer patients' quality of life.

Near Infrared (NIR) Fluorescence is Not a Substitute for Lymphoscintigraphy and Gamma Probe for Melanoma Sentinel Node Detection: Results from a Prospective Trial.

BACKGROUND: Sentinel lymph node (SLN) biopsy is the standard care for early detection and staging of lymph node metastasis in melanomas. Radiocolloids (RC) and blue dyes are used for SLN detection. Recently, near infrared (NIR) fluorescence tracing using indocyanine green has been developed as an alternative method for SLN detection. The relatively high tissue penetration depth of several millimeters and the ability to detect low concentrations of tracer both suggest that NIR may have significant advantages over RC and the blue dye methods. The objective of this study was to prospectively compare the performance of all three SLN detection techniques using them sequentially to evaluate the same group of patients. METHODS: One hundred twenty-one primary cutaneous melanoma patients with an indication for SLN biopsy were assigned to the procedure following NIR, blue dye, and RC detection techniques. RESULTS: No adverse event was reported. SLN was not detected in only 4.1% of cases. In 90.9%, an SLN was identified with NIR, but without any auxiliary technique in only 70.2% of cases. RC detected the SLN in 92.6% of cases. Patent blue was found in the sentinel node in 76.9%. The combination of all three techniques detected an SLN in 95.9% of cases. Metastases were present in 26.7%. The false-negative rate was 8.8%, with a negative predictive value of 91.2%. CONCLUSIONS: RC was the only technique with high SLN detection. Both the blue dye and NIR methods added sensitivity to the detection rate but should not be a substitute for RC.

Indoleamine 2,3-dioxygenase in melanoma progression and BRAF inhibitor resistance.

Indoleamine 2,3-dioxygenase (IDO) is associated with the progression of many types of tumors, including melanoma. However, there is limited information about IDO modulation on tumor cell itself and the effect of BRAF inhibitor (BRAFi) treatment and resistance. Herein, IDO expression was analyzed in different stages of melanoma development and progression linked to BRAFi resistance. IDO expression was increased in primary and metastatic melanomas from patients' biopsies, especially in the immune cells infiltrate. Using a bioinformatics approach, we also identified an increase in the IDO mRNA in the vertical growth and metastatic phases of melanoma. Using in silico analyses, we found that IDO mRNA was increased in BRAFi resistance. In an in vitro model, IDO expression and activity induced by interferon-gamma (IFNγ) in sensitive melanoma cells was decreased by BRAFi treatment. However, cells that became resistant to BRAFi presented random IDO expression levels. Also, we identified that treatment with the IDO inhibitor, 1-methyltryptophan (1-MT), was able to reduce clonogenicity for parental and BRAFi-resistant cells. In conclusion, our results support the hypothesis that the decreased IDO expression in tumor cells is one of the many additional outcomes contributing to the therapeutic effects of BRAFi. Still, the IDO production changeability by the BRAFi-resistant cells reiterates the complexity of the response arising from resistance, making it not possible, at this stage, to associate IDO expression in tumor cells with resistance. On the other hand, the maintenance of 1-MT off-target effect endorses its use as an adjuvant treatment of melanoma that has become BRAFi-resistant.

Independent external validation of nomogram to predict extracapsular extension in patients with prostate cancer.

INTRODUCTION: The objective of this study was to perform an independent external validation of the Giganti-Coppola nomogram (GCN), which uses clinical and radiological parameters to predict prostate extracapsular extension (ECE) on the final pathology of patients undergoing radical prostatectomy (RP). MATERIAL AND METHODS: Seventy-two patients diagnosed with prostate cancer (PCa), who were RP candidates from two institutions, were prospectively included. All patients underwent preoperative multi-parametric magnetic resonance imaging (mpMRI) at 1.5 T, without the use of an endorectal coil, with multiplanar images in T1WI, T2WI, DWI, and DCE. The AUC and a calibration graph were used to validate the nomogram, using the regression coefficients of the Giganti-Coppola study. RESULTS: The original nomogram had an AUC of 0.90 (p = 0.001), with a sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 100%, 5.1%, 47.1%, 100%, and 48%, respectively. The calibration graph showed an overestimation of the nomogram for ECE. CONCLUSION: The GCN has an adequate ability in predicting ECE; however, in our sample, it showed limited accuracy and overestimated likelihood of ECE in the final pathology of patients with PCa submitted to RP. KEY POINTS: • Knowledge of preoperative local staging of prostate cancer is essential for surgical treatment. Extracapsular extension increases the chance of positive surgical margins. • Imaging modalities such as mpMRI alone does not have suitable accuracy in local staging. • Giganti-Coppola's nomogram achieved an adequate ability in predicting ECE.

Vemurafenib resistance increases melanoma invasiveness and modulates the tumor microenvironment by MMP-2 upregulation.

The BRAF(V600E) mutation confers constitutive kinase activity and accounts for >90% of BRAF mutations in melanoma. This genetic alteration is a current therapeutic target; however, the antitumorigenic effects of the BRAF(V600E) inhibitor vemurafenib are short-lived and the majority of patients present tumor relapse in a short period after treatment. Characterization of vemurafenib resistance has been essential to the efficacy of next generation therapeutic strategies. Herein, we found that acute BRAF inhibition induced a decrease in active MMP-2, MT1-MMP and MMP-9, but did not modulate the metalloproteinase inhibitors TIMP-2 or RECK in naïve melanoma cells. In vemurafenib-resistant melanoma cells, we observed a lower growth rate and an increase in EGFR phosphorylation followed by the recovery of active MMP-2 expression, a mediator of cancer metastasis. Furthermore, we found a different profile of MMP inhibitor expression, characterized by TIMP-2 downregulation and RECK upregulation. In a 3D spheroid model, the invasion index of vemurafenib-resistant melanoma cells was more evident than in its non-resistant counterpart. We confirmed this pattern in a matrigel invasion assay and demonstrated that use of a matrix metalloproteinase inhibitor reduced the invasion of vemurafenib resistant melanoma cells but not drug naïve cells. Moreover, we did not observe a delimited group of cells invading the dermis in vemurafenib-resistant melanoma cells present in a reconstructed skin model. The same MMP-2 and RECK upregulation profile was found in this 3D skin model containing vemurafenib-resistant melanoma cells. Acute vemurafenib treatment induces the disorganization of collagen fibers and consequently, extracellular matrix remodeling, with this pattern observed even after the acquisition of resistance. Altogether, our data suggest that resistance to vemurafenib induces significant changes in the tumor microenvironment mainly by MMP-2 upregulation, with a corresponding increase in cell invasiveness.

Immunohistochemistry assessment of tissue neutrophil-to-lymphocyte ratio predicts outcomes in melanoma patients treated with anti-programmed cell death 1 therapy.

Elevated neutrophil-to-lymphocyte ratio (NLR) is associated with diminished immunotherapy response in metastatic melanoma. Although NLR assessment in peripheral blood is established, tissue dynamics remain insufficiently explored. This study aimed to evaluate tissue NLR (tNLR)'s predictive potential through immunohistochemistry in immunotherapy-treated melanoma. Fifty melanoma patients who underwent anti-programmed cell death 1 (PD-1) therapy were assessed. Hematological, clinical and tumor features were collected from medical records. Responses were categorized using the Response Evaluation Criteria in Solid Tumors for immunotherapy (iRECIST) guidelines. Immunohistochemistry for tumor-infiltrating T cells (cluster differentiation 3) and neutrophils (myeloperoxidase) was performed on formalin-fixed paraffin-embedded tumor samples. NLR, derived NLR (dNLR) and tNLR were calculated. Overall survival (OS) and survival following immunotherapy (SFI) were calculated from diagnosis or immunotherapy start to loss of follow-up or death. Patients with high tNLR presented improved OS ( P =  0.038) and SFI with anti-PD-1 therapy ( P =  0.006). Both NLR and dNLR were associated with OS ( P =  0.038 and P =  0.046, respectively) and SFI ( P =  0.001 and P =  0.019, respectively). NLR was also associated with immunotherapy response ( P =  0.007). In conclusion, tNLR emerged as a novel potential biomarker of enhanced survival post anti-PD-1 therapy, in contrast to classical NLR and dNLR markers.

Establishment and molecular characterization of HCB-541, a novel and aggressive human cutaneous squamous cell carcinoma cell line.

Cutaneous squamous cell carcinoma (cSCC) is a common type of skin cancer that can result in significant morbidity, although it is usually well-managed and rarely metastasizes. However, the lack of commercially available cSCC cell lines hinders our understanding of this disease. This study aims to establish and characterize a new metastatic cSCC cell line derived from a Brazilian patient. A tumor biopsy was taken from a metastatic cSCC patient, immortalized, and named HCB-541 after several passages. The cytokeratin expression profile, karyotypic alterations, mutational analysis, mRNA and protein differential expression, tumorigenic capacity in xenograft models, and drug sensitivity were analyzed. The HCB-541 cell line showed a doubling time between 20 and 30 h and high tumorigenic capacity in the xenograft mouse model. The HCB-541 cell line showed hypodiploid and hypotetraploidy populations. We found pathogenic mutations in TP53 p.(Arg248Leu), HRAS (Gln61His) and TERT promoter (C228T) and high-level microsatellite instability (MSI-H) in both tumor and cell line. We observed 37 cancer-related genes differentially expressed when compared with HACAT control cells. The HCB-541 cells exhibited high phosphorylated levels of EGFR, AXL, Tie, FGFR, and ROR2, and high sensitivity to cisplatin, carboplatin, and EGFR inhibitors. Our study successfully established HCB-541, a new cSCC cell line that could be useful as a valuable biological model for understanding the biology and therapy of metastatic skin cancer.

Effect of adjuvant chemoradiotherapy on overall survival of gastric cancer patients submitted to D2 lymphadenectomy.

BACKGROUND: Adjuvant chemoradiotherapy (CRT) is the standard treatment in Western countries for gastric cancer patients submitted to curative resection. However, the role of adjuvant CRT in gastric cancer treated with D2 lymphadenectomy has not been well defined. METHODS: We conducted a retrospective study in patients with stage II to IV gastric adenocarcinoma with no distant metastases, who underwent curative resection with D2 lymphadenectomy between January 2002 and December 2007. The present study compared the 3-year overall survival of two treatments (adjuvant CRT according to the INT 0116 trial versus resection alone). Survival curves were estimated by the Kaplan-Meier method and compared with a log-rank test. Multivariate analysis of prognostic factors was performed by the Cox proportional hazards model. RESULTS: A total of 185 patients were included, 104 patients (56 %) received adjuvant CRT and 81 received resection alone. The 3-year overall survival was 64.4 % in the CRT group and 61.7 % in the resection-alone group (p: 0.415). However, according to the Cox proportional hazards model, adjuvant CRT was a prognostic factor for 3-year overall survival (hazard ratio [HR] 0.46, 95 % confidence interval [CI] 0.26-0.82, p: 0.008). CONCLUSIONS: In the present study, adjuvant CRT was associated with a lower risk of death over a 3-year period in gastric cancer patients treated with D2 lymphadenectomy.

Treatment of patients with multiple brain metastases by isolated radiosurgery: Toxicity and survival.

BACKGROUND: Radiosurgery for multiple brain metastases has been more reported recently without using whole-brain radiotherapy. Nevertheless, the sparsity of the data still claims more information about toxicity and survival and their association with both dosimetric and geometric aspects of this treatment. AIM: To assess the toxicity and survival outcome of radiosurgery in patients with multiple (four or more lesions) brain metastases. METHODS: In a single institution, data were collected retrospectively from patients who underwent radiosurgery to treat brain metastases from diverse primary sites. Patients with 4-21 brain metastases were treated with a single fraction with a dose of 18 Gy or 20 Gy. The clinical variables collected were relevant to toxicity, survival, treatment response, planning, and dosimetric variables. The Spearman's rank correlation coefficients, Mann-Whitney test, Kruskal-Wallis test, and Log-rank test were used according to the type of variable and outcomes. RESULTS: From August 2017 to February 2020, 55 patients were evaluated. Headache was the most common complaint (38.2%). The median overall survival (OS) for patients with karnofsky performance status (KPS) > 70 was 8.9 mo, and this was 3.6 mo for those with KPS ≤ 70 (P = 0.047). Patients with treated lesions had a median progression-free survival of 7.6 mo. There were no differences in OS (19.7 vs 9.5 mo) or progression-free survival (10.6 vs 6.3 mo) based on prior irradiation. There was no correlation found between reported toxicities and planning, dosimetric, and geometric variables, implying that no additional significant toxicity risks appear to be added to the treatment of multiple (four or more) lesions. CONCLUSION: No associations were found between the evaluated toxicities and the planning dosimetric parameters, and no differences in survival rates were detected based on previous treatment status.

PD-L1 Tumor Expression as a Predictive Biomarker of Immune Checkpoint Inhibitors' Response and Survival in Advanced Melanoma Patients in Brazil.

Immune checkpoint blockade (ICB) agents are prominent immunotherapies for the treatment of advanced melanoma. However, they fail to promote any durable clinical benefit in a large cohort of patients. This study assessed clinical and molecular predictors of ICB response and survival in advanced melanoma. A retrospective analysis was performed on 210 patients treated with PD-1 or CTLA-4 inhibitors at Barretos Cancer Hospital, Brazil. PD-L1 expression was assessed by immunohistochemistry using formalin-fixed paraffin-embedded tumor tissues collected prior to ICB therapy. Patients were divided into responders (complete and partial response and stable disease for more than 6 months) and non-responders (stable disease for less than 6 months and progressive disease). Among them, about 82% underwent anti-PD-1 immunotherapy, and 60.5% progressed after the ICB treatment. Patients that received ICB as first-line therapy showed higher response rates than previously treated patients. Higher response rates were further associated with superficial spreading melanomas and positive PD-L1 expression (>1%). Likewise, PD-L1 positive expression and BRAF V600 mutations were associated with a higher overall survival after ICB therapy. Since ICBs are expensive therapies, evaluation of PD-L1 tumor expression in melanoma patients should be routinely assessed to select patients that are most likely to respond.

Co-expression of monocarboxylate transporter 1 (MCT1) and its chaperone (CD147) is associated with low survival in patients with gastrointestinal stromal tumors (GISTs).

Monocarboxylate transporters (MCTs) have been described to play an important role in cancer, but to date there are no reports on the significance of MCT expression in gastrointestinal stromal tumors (GISTs). The aim of the present work was to assess the value of MCT expression, as well as co-expression with the MCT chaperone CD147 in GISTs and evaluate their clinical-pathological significance. We analyzed the immunohistochemical expression of MCT1, MCT2, MCT4 and CD147 in a series of 64 GISTs molecularly characterized for KIT, PDGFRA and BRAF mutations. MCT1, MCT2 and MCT4 were highly expressed in GISTs. CD147 expression was associated with mutated KIT (p = 0.039), as well as a progressive increase in Fletcher's Risk of Malignancy (p = 0.020). Importantly, co-expression of MCT1 with CD147 was associated with low patient's overall survival (p = 0.037). These findings suggest that co-expression of MCT1 with its chaperone CD147 is involved in GISTs aggressiveness, pointing to a contribution of cancer cell metabolic adaptations in GIST development and/or progression.

Cutaneous and acral melanoma cross-OMICs reveals prognostic cancer drivers associated with pathobiology and ultraviolet exposure.

Ultraviolet radiation (UV) is causally linked to cutaneous melanoma, yet the underlying epigenetic mechanisms, known as molecular sensors of exposure, have not been characterized in clinical biospecimens. Here, we integrate clinical, epigenome (DNA methylome), genome and transcriptome profiling of 112 cutaneous melanoma from two multi-ethnic cohorts. We identify UV-related alterations in regulatory regions and immunological pathways, with multi-OMICs cancer driver potential affecting patient survival. TAPBP, the top gene, is critically involved in immune function and encompasses several UV-altered methylation sites that were validated by targeted sequencing, providing cost-effective opportunities for clinical application. The DNA methylome also reveals non UV-related aberrations underlying pathological differences between the cutaneous and 17 acral melanomas. Unsupervised epigenomic mapping demonstrated that non UV-mutant cutaneous melanoma more closely resembles acral rather than UV-exposed cutaneous melanoma, with the latter showing better patient prognosis than the other two forms. These gene-environment interactions reveal translationally impactful mechanisms in melanomagenesis.

Opportunistic screening for skin cancer using a mobile unit in Brazil.

BACKGROUND: Skin cancer is the most common malignancy in the white population worldwide. In Brazil, the National Cancer Institute (INCA) estimates that in 2010 there will be 119,780 and 5,930 new cases of non-melanoma skin cancer and melanoma, respectively. The aim of this study was to evaluate the use of a mobile unit in the diagnosis and treatment of skin cancer in several poor regions of Brazil. METHODS: The diagnosis of skin cancer was accomplished through active medical screening in the prevention Mobile Unit (MU) of Barretos Cancer Hospital (BCH). The study population consisted of patients examined in the MU between 2004 and 2007, and their suspicious lesions were subjected to histopathological evaluation. Data were collected prospectively from standardized forms and analyzed. RESULTS: During the screening, 17,857 consultations were carried out. A total of 2012 (11.2%) cases of skin cancer were diagnosed. The predominant histological type reported was basal cell carcinoma (n = 1,642 or 81.6%), followed by squamous cell carcinoma (n = 303 or 15.1%), Bowen's disease (n = 25 or 1.2%), malignant melanoma (n = 23 or 1.1%), basosquamous cell carcinoma (n = 3 or 0.1%), miscellaneous lesions (12 or 0.6%), and metatypical carcinoma (n = 4 or 0.2%). Only 0.6% of lesions were stage III. There were no stage IV non-melanoma skin lesions, as well as no melanomas stages III and IV, found. CONCLUSIONS: It was observed that the MU can be a useful tool for early skin cancer diagnosis and treatment. This program probably is important, especially in developing countries with inadequate public health systems and social inequality.

Genetic variability in COVID-19-related genes in the Brazilian population.

SARS-CoV-2 utilizes the angiotensin-converting enzyme 2 (ACE2) receptor and transmembrane serine protease (TMPRSS2) to infect human lung cells. Previous studies have suggested that different host ACE2 and TMPRSS2 genetic backgrounds might contribute to differences in the rate of SARS-CoV-2 infection or COVID-19 severity. Recent studies have also shown that variants in 15 genes related to type I interferon immunity to influenza virus might predispose patients toward life-threatening COVID-19 pneumonia. Other genes (SLC6A20, LZTFL1, CCR9, FYCO1, CXCR6, XCR1, IL6, CTSL, ABO, and FURIN) and HLA alleles have also been implicated in the response to infection with SARS-CoV-2. Currently, Brazil has recorded the third-highest number of COVID-19 cases worldwide. We aimed to investigate the genetic variation present in COVID-19-related genes in the Brazilian population. We analyzed 27 candidate genes and HLA alleles in 954 admixed Brazilian exomes. We used the information available in two public databases (http://www.bipmed.org and http://abraom.ib.usp.br/) and additional exomes from individuals born in southeast Brazil, the region of the country with the highest number of COVID-19 patients. Variant allele frequencies were compared with the 1000 Genomes Project phase 3 (1KGP) and gnomAD databases. We detected 395 nonsynonymous variants; of these, 325 were also found in the 1KGP and/or gnomAD. Six of these variants were previously reported to influence the rate of infection or clinical prognosis of COVID-19. The remaining 70 variants were identified exclusively in the Brazilian sample, with a mean allele frequency of 0.0025. In silico analysis revealed that seven of these variants are predicted to affect protein function. Furthermore, we identified HLA alleles previously associated with the COVID-19 response at loci DQB1 and DRB1. Our results showed genetic variability common to other populations and rare and ultrarare variants exclusively found in the Brazilian population. These findings might lead to differences in the rate of infection or response to infection by SARS-CoV-2 and should be further investigated in patients with this disease.

Exploring a Region on Chromosome 8p23.1 Displaying Positive Selection Signals in Brazilian Admixed Populations: Additional Insights Into Predisposition to Obesity and Related Disorders.

We recently reported a deviation of local ancestry on the chromosome (ch) 8p23.1, which led to positive selection signals in a Brazilian population sample. The deviation suggested that the genetic variability of candidate genes located on ch 8p23.1 may have been evolutionarily advantageous in the early stages of the admixture process. In the present work, we aim to extend the previous work by studying additional Brazilian admixed individuals and examining DNA sequencing data from the ch 8p23.1 candidate region. Thus, we inferred the local ancestry of 125 exomes from individuals born in five towns within the Southeast region of Brazil (São Paulo, Campinas, Barretos, and Ribeirão Preto located in the state of São Paulo and Belo Horizonte, the capital of the state of Minas Gerais), and compared to data from two public Brazilian reference genomic databases, BIPMed and ABraOM, and with information from the 1000 Genomes Project phase 3 and gnomAD databases. Our results revealed that ancestry is similar among individuals born in the five Brazilian towns assessed; however, an increased proportion of sub-Saharan African ancestry was observed in individuals from Belo Horizonte. In addition, individuals from the five towns considered, as well as those from the ABRAOM dataset, had the same overrepresentation of Native-American ancestry on the ch 8p23.1 locus that was previously reported for the BIPMed reference sample. Sequencing analysis of ch 8p23.1 revealed the presence of 442 non-synonymous variants, including frameshift, inframe deletion, start loss, stop gain, stop loss, and splicing site variants, which occurred in 24 genes. Among these genes, 13 were associated with obesity, type II diabetes, lipid levels, and waist circumference (PRAG1, MFHAS1, PPP1R3B, TNKS, MSRA, PRSS55, RP1L1, PINX1, MTMR9, FAM167A, BLK, GATA4, and CTSB). These results strengthen the hypothesis that a set of variants located on ch 8p23.1 that result from positive selection during early admixture events may influence obesity-related disease predisposition in admixed individuals of the Brazilian population. Furthermore, we present evidence that the exploration of local ancestry deviation in admixed individuals may provide information with the potential to be translated into health care improvement.

Caution is needed in interpreting the results of comparative studies regarding oncological operations by minimally invasive versus laparotomic access.

We aim to alert the difference between groups while comparing studies of abdominal oncological operations performed either by minimally invasive or laparotomic approaches and potential conflicts of interest in presenting or interpreting the results. Considering the large volume of scientific articles that are published, there is a need to consider the quality of the scientific production that leads to clinical decision making. In this regards, it is important to take into account the choice of the surgical access route. Randomized, controlled clinical trials are the standard for comparing the effectiveness between these interventions. Although some studies indicate advantages in minimally invasive access, caution is needed when interpreting these findings. There is no detailed observation in each of the comparative study about the real limitations and potential indications for minimally invasive procedures, such as the indications for selected and less advanced cases, in less complex cavities, as well as its elective characteristic. Several abdominal oncological operations via laparotomy would not be plausible to be completely performed through a minimally invasive access. These cases should be carefully selected and excluded from the comparative group. The comparison should be carried out, in a balanced way, with a group that could also have undergone a minimally invasive access, avoiding bias in selecting those cases of minor complexity, placed in the minimally invasive group. It is not a question of criticizing the minimally invasive technologies, but of respecting the surgeon's clinical decision regarding the most convenient method, revalidating the well-performed traditional laparotomy route, which has been unfairly criticized or downplayed by many people.

Circulating tumor DNA (ctDNA) detection is associated with shorter progression-free survival in advanced melanoma patients.

BRAF, NRAS and TERT mutations occur in more than 2/3 of melanomas. Its detection in patient's blood, as circulating tumor DNA (ctDNA), represents a possibility for identification and monitoring of metastatic disease. We proposed to standardize a liquid biopsy platform to identify hotspot mutations in BRAF, NRAS and TERT in plasma samples from advanced melanoma patients and investigate whether it was associated to clinical outcome. Firstly, we performed digital polymerase chain reaction using tumor cell lines for validation and determination of limit of detection (LOD) of each assay and screened plasma samples from healthy individuals to determine the limit of blank (LOB). Then, we selected 19 stage III and IV patients and determined the somatic mutations status in tumor tissue and track them in patients' plasma. We established a specific and sensitive methodology with a LOD ranging from 0.13 to 0.37%, and LOB ranging from of 0 to 5.201 copies/reaction. Somatic mutations occurred in 17/19 (89%) patients, of whom seven (41%) had ctDNA detectable their paired plasma. ctDNA detection was associated with shorter progression free survival (p = 0.01). In conclusion, our data support the use of ctDNA as prognosis biomarker, suggesting that patients with detectable levels have an unfavorable outcome.