Publications by authors named "Juan M O Connor"

Neuroendocrine carcinomas are rare and aggressive malignancies, often diagnosed at advanced stages, leading to poor prognosis. Platinum-based chemotherapy is the standard first-line treatment for advanced neuroendocrine carcinomas; however after achieving response no consensus exists on maintenance therapies and the results are inconsistent. This review examines the role of maintenance therapy following response to first-line chemotherapy in gastroenteropancreatic neuroendocrine carcinomas.

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Objectives: We aim to investigate the time toxicity of patients with gastroenteropancreatic neuroendocrine tumours treated with Lutetium-177 Dotatate in a single institution.

Design: This is a retrospective cohort study.

Methods: All patients with gastroenteropancreatic neuroendocrine tumours treated with Lutetium-177 Dotatate at the Alexander Fleming Institute were included.

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Background: The standard neoadjuvant therapy for rectal cancer involves fluoropyrimidines and radiotherapy and, most recently, total neoadjuvant therapy (TNT). A drug-drug interaction between fluoropyrimidines and proton-pump inhibitors (PPI) was suggested, with a negative impact on oncological outcomes in breast, colon and gastric cancers. Little is known about such an effect on rectal tumours.

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Article Synopsis
  • The study aimed to evaluate the Immunoscore (IS) as a potential biomarker for patients with rectal cancer managed by a watch-and-wait (W&W) strategy, focusing on predicting recurrence after treatment.
  • It involved 249 patients and analyzed the presence of specific immune cells in pre-treatment biopsies, finding that higher IS scores were associated with better 5-year recurrence-free rates.
  • The results indicate that IS is a strong independent predictor of time to recurrence and improves the accuracy of clinical models in assessing patient outcomes.
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Advances in genomic technologies have significantly improved the management of colorectal cancer (CRC). Several biomarkers have been identified in CRC that enable personalization in the use of biologic agents that have shown to enhance the clinical outcomes of patients. However, technologies used for their determination generate massive amounts of information that can be difficult for the clinician to interpret and use adequately.

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Background: Immunotherapy is the first-line treatment in patients with advanced microsatellite instability-high (MSI-H) or deficient mismatch repair (dMMR) colorectal cancer (CRC). Although immune checkpoint inhibitors (ICIs) for locally advanced rectal cancer (LARC) are not yet a standard, the results are very encouraging and raise the question of whether patients with clinical complete response (cCR) could receive nonoperative management (NOM). However, different patterns of response have challenged management strategies.

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Background: Short-course radiotherapy (SCRT) of 25 Gy in five daily fractions is a recommended strategy in the neoadjuvant setting for resectable locally advanced rectal cancer (LARC), as well as in cases of metastatic disease for local control. There is scarce information regarding the use of SCRT for patients who have received nonoperative management.

Objectives: To describe the characteristics of patients who received treatment with SCRT for LARC and metastatic rectal cancer, toxicity, and the approach after radiation treatment.

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Background: Prognostic and predictive markers in metastatic pheochromocytoma and paraganglioma (mPPGL) are unknown. We aimed to evaluate epidemiology of mPPGL, and prognostic factors of overall survival (OS) and predictive markers of treatment duration with first-line chemotherapy (TD1L).

Patients And Methods: Retrospective multicentre study of adult patients with mPPGL treated in Latin American centres between 1982 and 2021.

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To analyze the frequency of and hotspot mutations in circulating tumor DNA (ctDNA) from patients with metastatic colorectal cancer (mCRC). Observational, descriptive and retrospective study in mCRC patients with available ctDNA-based genotype of , and . The frequencies of plasma mutations for , and were 34% (± 7), 4% (± 3) and 4% (± 3), respectively.

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Given the increasing complexity of cancer care, multidisciplinary tumor boards have become essential in daily clinical oncology practice. The Project Extension for Community Healthcare Outcomes (ECHO) initiative developed an innovative telementoring model using a "hub and spoke" design consisting of a team of experts (hub) that offers a full service to multiple participants (the spokes) during regularly scheduled sessions discussing patients' clinical cases. The Alexander Fleming Cancer Institute in Buenos Aires was the first hub in Latin America to implement Project ECHO for gastrointestinal tumors.

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Background: Gastric Cancer (GC) is the fourth most deadly cancer worldwide. Enhanced understanding of its key epidemiological and molecular drivers is urgently needed to lower the incidence and improve outcomes. Furthermore, tumor biology in European (EU) and Latin American (LATAM) countries is understudied.

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Importance: In patients with resectable colorectal cancer liver metastases (CRLM), the choice of surgical technique and resection margin are the only variables that are under the surgeon's direct control and may influence oncologic outcomes. There is currently no consensus on the optimal margin width.

Objective: To determine the optimal margin width in CRLM by using artificial intelligence-based techniques developed by the Massachusetts Institute of Technology and to assess whether optimal margin width should be individualized based on patient characteristics.

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Background: The role of the molecular tumour board (MTB) is to recommend personalised therapy for patients with cancer beyond standard-of-care treatment. A comprehensive molecular analysis of the tumour in a molecular pathology laboratory is important for all targeted therapies approaches. Here we report the 1-year experience of the Instituto Alexander Fleming Molecular Tumour Board.

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The SCOPE project aimed to better understand practice patterns, identify drivers for treatment goals, and determine third- and fourth-line treatment choices for patients with metastatic colorectal cancer (mCRC). The survey was developed by an expert panel of gastrointestinal oncologists. Questions concerned general practice patterns, and treatment decisions for three hypothetical patient case scenarios.

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Background: HIV-positive patients are underrepresented in clinical trials of metastatic squamous cell carcinoma of the anal canal (mSCCA). We aimed to compare the clinical outcomes of mSCCA patients according to HIV infection.

Methods: This was a retrospective multicenter cohort study of consecutive patients with mSCCA.

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Introduction: Two novel clinical risk scores (CRS) that incorporate KRAS mutation status were developed: modified CRS (mCRS) and GAME score. However, they have not been tested in large national and international cohorts. The aim of this study was to validate the prognostic discrimination utility and determine the clinical usefulness of the two novel CRS.

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Colorectal cancer (CRC) is one of the most commonly diagnosed cancers in Central and South America and one of the top causes of cancer death; however, these rates vary considerably between countries. This commentary focuses on clinical experiences in Argentina, highlighting results of the phase II ReDOS trial.

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Background: Carcinoid heart disease (CHD) is a rare and severe complication from carcinoid syndrome which may be associated with high health resource utilisation (HRU). We aimed to compare HRU between patients with and without CHD.

Methods: Multicentre retrospective study of 137 consecutive patients with neuroendocrine tumours (NET) and elevated urinary 5-hydroxyindoleacetic acid treated in seven large hospitals in Latin America.

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Introduction: The incidence of infections is poorly studied in patients with neuroendocrine tumors (NET) treated with everolimus outside of clinical trials. We aimed to evaluate the frequency of and risk factors for opportunistic infections (Opl) or any serious infection in eligible patients.

Methods: This was a retrospective multicenter study of a Latin American cohort of consecutive patients with advanced NET treated with everolimus.

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Purpose The vasopressin analog desmopressin (dDAVP) is known to increase plasma levels of hemostatic factors, and preclinical studies in colorectal cancer models have demonstrated that it hampers tumor vascularization and metastatic progression. We evaluated safety and preliminary efficacy of dDAVP in rectal cancer patients with bleeding, before receiving specific oncologic treatment with surgery, chemotherapy and/or radiotherapy. Methods Patients with rectal cancer having moderate or severe rectal bleeding were enrolled in an open-label, dose-finding trial.

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Background: Regorafenib prolonged overall survival (OS) versus placebo in patients with treatment-refractory metastatic colorectal cancer (mCRC) in phase III trials. We conducted an observational study of regorafenib for patients with mCRC in real-world clinical practice.

Methods: The international, prospective, CORRELATE study recruited patients with mCRC previously treated with approved therapies, for whom the decision to treat with regorafenib was made by the treating physician according to the local health authority approved label.

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Aim: To assess patient and disease characteristics, treatment patterns and associated costs in patients with locally advanced or metastatic gastric cancer in Argentina, in the public and private sectors.

Methods: A historic cohort of patients who had received first-line chemotherapy treatment (platinum analog and/or a fluoropyrimidine) and were followed-up for at least three months after the last administration of a first-line cytotoxic agent were eligible. Case-report forms were prepared based on medical records from four Argentinian hospitals.

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To determine the impact of KRAS mutation status on survival in patients undergoing surgery for colorectal liver metastases (CLM). Patients with resected CLM and KRAS mutations. Survival was compared between mt-KRAS and wt-KRAS.

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