33 Journal of Oncology Research | Volume 03 | Issue 02 | July 2021 Distributed under creative commons license 4.0 Journal of Oncology Research https://ojs.bilpublishing.com/index.php/jor *Corresponding Author: Adriana Vial Roehe, Department of Pathology, Graduate Programa in Pathology, Federal University of Health Sciences of Porto Alegre (UFCSPA), Porto Alegre, Brazil; Email: adrianar@ufcspa.edu.br; aroehe@gmail.com DOI: https://doi.org/10.30564/jor.v3i2.3632 ARTICLE The Loss of Heterozygosity of FHIT Gene in Sporadic Breast Cancer Lisiane Silveira Zavalhia 1 Andrea Pires Souto Damin 2 Grasiela Agnes 3 Aline Weber 1 Taís Frederes Kramer Alcalde 1 Laura Marinho Dorneles 1 Guilherme Watte 4 Adriana Vial Roehe 5* 1. Research Laboratory in Pathology, Graduate Program in Pathology, Federal University of Health Sciences of Porto Alegre (UFCSPA), Brazil 2. Department of Gynecology and Obstetrics of Federal University, Rio Grande do Sul (UFRGS), Porto Alegre, Brazil 3. Research Laboratory in Molecular Biology, Federal University of Health Sciences of Porto Alegre (UFCSPA), Rio Grande do Sul, Brazil 4. Department of Respiratory Medicine and Thoracic Surgery, Irmandade da Santa Casa de Misericordia de Porto Alegre, Rio Grande do Sul, Brazil 5. Department of Pathology, Graduate Programa in Pathology, Federal University of Health Sciences of Porto Alegre (UFCSPA), Porto Alegre, Brazil ARTICLE INFO ABSTRACT Article history Received: 25 August 2021 Accepted: 7 September 2021 Published Online: 13 September 2021 The loss of heterozygosity (LOH) is a genetic event that can change gene function. FHIT is a potential tumor suppressor gene. Although the precise FHIT molecular mechanism of action is not well understood, evidences suggest that Fhit protein reduced levels are involved in mammary carcinogenesis. The aim of this study was to investigate if FHIT LOH could infuence on sporadic breast cancer (BC) biological behavior, through its association with prognostic factors for sporadic BC. Tumor tissue and peripheral blood samples were analyzed using the microsatellite marker D3S1300. The findings were associated with clinicopathological parameters including overall survival. LOH was detected in 31.1%(52/167) of the informative BC’ cases. Considering clinical and pathological characteristics we have found no significant association with FHIT LOH status. The mean follow-up time was 80 months. After the Cox regression analysis two parameters remained associated with BC’s risk of death: TNM stage III and IV - HR = 3.74(95% CI, 1.16-12.1) P=0.027 and disease relapse HR = 3.14(CI 95% 1.26-7.80) P =0.014. This study shows that FHIT LOH by itself is not a prognostic factor for sporadic BC. Further researches are required to elucidate the functional role of FHIT LOH concerning to BC. Keywords: Breast cancer D3S1300 LOH Survival Loss of heterozygosity 1. Introduction Breast cancer remains the most common cause of can- cer-related deaths in women globally [1] . Innumerous are the efforts to fnd and understand the set of genetic and epigenetic changes that can influence mammary carcinogenesis and tumor biological behavior [2] .