Publications by authors named "Leonard M Da Silva"

Article Synopsis
  • The study explores challenges in lung cancer biomarker testing due to tissue inadequacy and operational issues, implementing a tailored molecular testing approach in Brazil.
  • From 1,272 lung cancer samples analyzed, a significant percentage were ineligible for testing due to insufficient tissue quality or quantity, with specific mutations and alterations being most commonly observed.
  • Results suggest that while non-NGS tests provided some diagnostic information, a substantial portion of patients could only access reduced molecular testing coverage, impacting the detection of actionable cancer drivers.
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The most widely accepted and used type of digital pathology (DP) is whole-slide imaging (WSI). The USFDA granted two WSI system approvals for primary diagnosis, the first in 2017. In Latin America, DP has the potential to reshape healthcare by enhancing diagnostic capabilities through artificial intelligence (AI) and standardizing pathology reports.

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Gastric cancer (GC) remains a formidable global health challenge, ranking among the top-five causes of cancer-related deaths worldwide. The majority of patients face advanced stages at diagnosis, with a mere 6% five-year survival rate. First-line treatment for metastatic GC typically involves a fluoropyrimidine and platinum agent combination; yet, predictive molecular markers have proven elusive.

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MUTYH-associated polyposis syndrome is an uncommon, autosomal recessive colorectal polyposis syndrome caused by biallelic inactivation of . Most patients present with multiple colorectal polyps. However, other primary tumor sites have been described as less frequent.

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Artificial intelligence (AI)-based systems applied to histopathology whole-slide images have the potential to improve patient care through mitigation of challenges posed by diagnostic variability, histopathology caseload, and shortage of pathologists. We sought to define the performance of an AI-based automated prostate cancer detection system, Paige Prostate, when applied to independent real-world data. The algorithm was employed to classify slides into two categories: benign (no further review needed) or suspicious (additional histologic and/or immunohistochemical analysis required).

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Clinical management of breast cancer families is complicated by identification of BRCA1 and BRCA2 sequence alterations of unknown significance. Molecular assays evaluating the effect of intronic variants on native splicing can help determine their clinical relevance. Twenty-six intronic BRCA1/2 variants ranging from the consensus dinucleotides in the splice acceptor or donor to 53 nucleotides into the intron were identified in multiple-case families.

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Missense substitutions in high-risk cancer susceptibility genes create clinical uncertainty in the genetic counseling process. Multifactorial likelihood classification approaches and in vitro assays are useful for the classification of exonic sequence variants in BRCA1 and BRCA2, but these currently rely on the assumption that changes in protein function are the major biological mechanism of pathogenicity. This study investigates the potentially pathogenic role of aberrant splicing for exonic variants predicted to encode missense substitutions using patient-derived RNA.

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Although in vitro splicing assays can provide useful information about the clinical interpretation of sequence variants in high-risk cancer genes such as BRCA1 and BRCA2, results can sometimes be difficult to interpret. The BRCA1 c.135-1G>T (IVS3-1G>T) variant has been shown to give rise to an in-frame deletion of exon 5 (BRCA1 c.

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Purpose: Rare missense substitutions and in-frame deletions of BRCA1 and BRCA2 genes present a challenge for genetic counseling of individuals carrying such unclassified variants. We assessed the value of tumor immunohistochemical markers in conjunction with genetic and evolutionary approaches for investigating the clinical significance of unclassified variants.

Patients And Methods: We studied 10 BRCA1 and 12 BRCA2 variants identified in Australian families with breast cancer.

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The frequency of in situ carcinomas has been rising since the introduction of mammographic screening. The management of patients with preinvasive disease remains difficult due to our lack of ability to accurately predict which patients will recur and progress to invasive carcinoma. Although some factors, such as lesion size and extent of margin clearance, are strong predictors of recurrence, many patients are still under- or overtreated.

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