Introduction: Early-onset colorectal cancer (EOCRC) has shown a global increase over recent decades, affecting individuals under the age of 50. Although there is evidence that EOCRC presents distinct molecular characteristics compared to late-onset colorectal cancer, data regarding populations from the Brazilian Amazon remain scarce. Objectives: This study aims to characterize the genetic and epigenetic profile of early-onset colorectal cancer in young adults from the Amazon region, exploring somatic mutations, polymorphisms, molecular signatures, as well as the influence of genomic ancestry on tumor susceptibility. Methods: This is a retrospective study involving young adults (<50 years) diagnosed with colorectal cancer in the Amazon region. Genotyping was performed using real-time PCR and next-generation sequencing (NGS). Single nucleotide polymorphisms (SNPs) in carcinogenesis-related genes and genomic ancestry were analyzed using 61 ancestry-informative markers (AIMs) and adjusted statistical analyses. Results: Genomic analyses revealed a complex and heterogeneous molecular profile in colorectal tumors of young adults from the Amazon. Recurrent mutations were identified in the PIK3CA, TP53, and KRAS genes, in addition to alterations in AXIN2, RNF43, and ARID1A, which are involved in epigenetic regulation and DNA repair. These findings suggest that carcinogenesis in young individuals may involve alternative pathways beyond the classical ones, such as activation of non-canonical Wnt signaling, genomic instability, and chromatin remodeler alterations. Furthermore, the rs1128503 polymorphism in the ABCB1 gene was associated with a lower risk of colorectal cancer, indicating a possible protective genetic role. Another relevant aspect was the influence of genomic ancestry. A high frequency of mutations in genes such as CDKN1A, MAP3K1, AURKA, EPCAM, and KDM5A was also observed, particularly in samples without a family history or known hereditary syndromes, reinforcing the hypothesis of a sporadic EOCRC subset with distinct molecular signatures. Additionally, tumors located in the right colon—more prevalent among young patients—exhibited increased rates of microsatellite instability (MSI), high tumor mutational burden (TMB), and mutations in DNA repair genes such as MSH2, POLE, and BRCA1, highlighting their potential as therapeutic targets, particularly in immunotherapy strategies. At the epigenetic level, EOCRC tumors were shown to rapidly accumulate methylation alterations, notably LINE-1 hypomethylation and the presence of 234 differentially methylated regions compared to late-onset tumors. Epigenetic markers were also detectable in peripheral blood leukocytes, suggesting that systemic changes may precede or accompany tumor development and offer new avenues for non-invasive screening. In this context, the presence of European, African, and Amerindian genetic components was found to alter the frequency of risk-associated variants, revealing a unique landscape of genetic susceptibility in this population. Such genetic admixture, still underrepresented in major international genomic consortia, may affect the functional interpretation of variants and influence clinical decisions regarding targeted therapies. Conclusion: Colorectal cancer in young adults from the Amazon region reveals a distinct genetic profile. The influence of ancestry and molecular heterogeneity underscores the need for personalized diagnostic strategies and the inclusion of admixed populations in genomic studies and precision medicine policies.
It is with great enthusiasm that we present the Annals of the Oncology International Symposium 2025, an event that continues to solidify its significance in the oncology landscape of northern Brazil. Held in Belém, Pará, Oncology 2025 centered around the theme "The cancer control challenge: better knowing it to best facing it," dedicating itself to exploring the latest frontiers in cancer treatment and prevention.
This year, the symposium provided a deep dive into the essential role of knowledge in the fight against cancer, presenting new perspectives and scientific advancements across various areas of oncology. Renowned global experts gathered to share their most recent research and innovative approaches, offering participants a comprehensive view of the challenges faced by healthcare professionals and patients worldwide.
Presentations and discussions during the event focused on critical topics such as the use of new technologies, advancements in personalized therapies, and more effective prevention strategies. Additionally, particular attention was given to the unique challenges faced by the Amazon region, with efforts aimed at developing region-specific solutions to meet local needs.
Beyond being a high-caliber academic event, Oncology 2025 stood out as a moment for integration and professional networking, with the warm hospitality of the city of Belém offering participants a unique experience. This event became a platform for exchanging ideas, where science, culture, and humanity came together in pursuit of a common goal: to improve cancer control both in Brazil and globally.
This collection of abstracts and articles presented during the event reflects the ongoing dedication to research and the development of innovative solutions, highlighting the importance of collaboration and shared knowledge in the fight against cancer.
General Submission Guidelines:
The presenting author, who does not have to be the first author, must be registered for Oncology 2025.
Each abstract may have up to 10 authors, including the main author and co-authors.
Only original, unpublished work will be accepted.
Submissions must be related to oncology. However, project descriptions, work proposals, experience reports, and literature reviews will not be considered.
Clinical case reports are allowed, provided the abstract addresses scientific questions, details clinical observations, and includes primary scientific data.
The abstract must be written in English, but presentations may be given in Portuguese.
Abstracts must be between 300 and 500 words.
Comissão Organizadora
Comissão Científica
See Annals of Oncology 2023 at:
https://www.even3.com.br/anais/oncology-2023-international-symposium/
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