Honors Program


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Finch A. 2023. Extranodal tumors and chromosomal abnormalities associated with non-Hodgkin lymphoma in t(14;18)-positive patients. Undergraduate Honors Thesis. University of Nebraska-Lincoln.


Copyright Alexis Finch 2023


Nebraska is mostly an agricultural state with a non-Hodgkin lymphoma (NHL) incidence rate of 20.1 per 100,000 individuals, which is greater than the US incidence rate of 19 per 100,000 individuals. It is possible that the higher incidence rate in Nebraska is due to an increase in pesticide usage. Pesticide exposure is linked to t(14;18), a genetic translocation involving the BCL2 gene that regulates apoptosis. The dysregulation of apoptosis could contribute to the proliferation of NHL. This exploratory study utilized the Nebraska Lymphoma Study Group, which consists of patients with non-Hodgkin lymphoma, Hodgkin disease, or some other neoplastic hematologic disorder and provides tumor histology, cytogenetics, immunology, and molecular information. Associations between various demographic and diagnostic factors were evaluated. Tumor subtype was significantly associated with anatomical location (X2 = 135.63, p < 0.0001), BCL6 expression (X2 = 28.62, p < 0.001), an additional X chromosome (X2 = 6.41, p = 0.041), and trisomy 12 (X2 = 6.55, p = 0.038). A follicular lymphoma tumor was more likely to express BCL6 than a diffuse large B-cell lymphoma (DLBCL) tumor (OR = 4.43, 95% CI = 1.31-14.93, p = 0.017) or other subtypes(OR = 17.69, 95% CI = 4.88-64.15, p < 0.001). Trisomy 7, trisomy 12, and a deletion of the long arm of chromosome 6 occurred more frequently in DLBCL than follicular lymphoma. DLBCL is an aggressive form of NHL while follicular lymphoma is indolent, which suggests that chromosomal aberrations may be associated with aggressiveness. This study population includes only t(14;18)-positive patients and future work should compare these findings with t(14;18)-negative patients and controls. Future work should also include t(14;18)-negative patients when evaluating the risk of developing t(14;18)-positive NHL after exposure to drinking water containing nitrate and atrazine.