Caracterização da instabilidade de microssatélites e níveis séricos de citocinas em pacientes com câncer colorretal atendidos em uma unidade terciária do Amazonas

Abstract

Colorectal cancer (CRC) is among the leading causes of cancer-related mortality worldwide and represents a growing challenge in the Amazon region. Microsatellite instability (MSI) is a key molecular biomarker for diagnosis and prognosis, while cytokines modulate the tumor microenvironment and immune response. This cross-sectional, observational, and analytical study aimed to describe MSI profiles and evaluate serum cytokine levels in patients with CRC treated at the Fundação Centro de Controle de Oncologia do Estado do Amazonas (FCECON). Between 2023 and 2025, sixty-six participants were recruited; six were excluded after confirmation of squamous cell carcinoma or anal canal cancer, resulting in 60 eligible patients. Paired tumor and peripheral blood samples were analyzed by PCR using the Applied Biosystems™ TrueMark™ MSI 13-marker panel and quantified with TrueMark™ Software. Serum levels of IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, TNF-α, IL-12p70, and IL-17A were determined by flow cytometry (BD™ Human Inflammatory Cytokines and Th1/Th2/Th17 kits). The frequency of MSI-H was 28.3% (17/60), whereas 71.7% (43/60) were classified as MSI-L/MSS. The markers BAT-40 (56.9%) and NR-22 (58.6%) showed the highest rates of instability, followed by NR-21 (34.5%), NR-24 (36.2%), and NR-27 (36.2%). MSI-H tumors were predominantly located in the right colon and showed a higher frequency in right-sided and mucinous tumors; however, no statistically significant associations were observed. No statistically significant associations were observed between MSI status and clinicopathological variables. However, higher IL-12p70 levels were detected in non-metastatic patients (p = 0.0187), suggesting a potential protective immune role. The results reinforce the molecular heterogeneity of CRC in the Amazonian population and highlight the importance of integrating molecular and immunological biomarkers such as MSI and cytokines in understanding tumor biology, contributing to the advancement of precision oncology and the improvement of therapeutic strategies.