Occupational Risk Factors for Laryngeal Cancer in Tunisia: A Case Control Study.

BACKGROUND: Tobacco use and alcohol consumption are the primary risk factors for laryngeal cancer (LC). In most populations, occupational exposures are likely to play a minor role in laryngeal carcinogenesis. We aimed to investigate the association between occupational exposure and laryngeal cancer. METHODS: It is a case-control study that included 140 cases diagnosed between January 2013 and December 2016 and 140 controls matched by sex, age, alcohol consumption, and tobacco consumption. RESULTS: Significantly increased risks were found amongst workers of the building sector (OR=4.621; 95% CI [1.826-11.693]) and the mechanical industry sector (OR=5.074; 95% CI [1.425-18.072]). Significant association of laryngeal cancer with various carcinogens was observed such as asbestos (p=0.009; OR=3.68; 95% CI [1.29-10.46]), paint vapors (p=0.005; OR=3.35; 95% CI [1.37-8.16]), solvents (p=0.001; OR=3.29: 95% CI [1.61-6.68]) and cement dust (p=0.003; OR=3.19: 95% CI [1.43-7.12]). After binary logistic regression, cement dust was independently correlated with LC (p=0.042; OR=3.93; 95% CI [1.04-14.78]. The administration sector was associated with decreased risk (p=0.001; OR=0.07; 95% CI [0.03-0.15]) as well as the health sector (p=0.001; OR=0.098; 95% CI [0.02-0.43]). CONCLUSIONS: Our results supported the role of occupational factors in developing LC. Further studies enabling an in-depth analysis of occupational exposures are necessary to provide a clearer definition of the etiological associations between single agents and circumstances of exposure and the genesis of LC.

Extranodal NK/T-cell lymphoma in Tunisia: clinicopathological features, immunophenotype and EBV infection.

BACKGROUND: Extranodal NK/T-cell lymphomas (ENKTL) are rare non-Hodgkin's lymphomas with aggressive clinical behavior. ENKTL are frequently associated with the Epstein-Barr virus (EBV). Data on ENKTL in Africa and Arab world are extremely limited. The study investigated the clinicopathological characteristics, EBV infection, and immunophenotype of ENKTL in Tunisia. We conducted a retrospective study of ENKTL. Main clinicopathological features were reported. The expression of CD3, CD4, CD5, CD8, CD20, CD56, CD57, and Granzyme B were analyzed by immunohistochemistry. EBV infection was detected by IHC (LMP-1) and Epstein-Barr encoding region (EBER1/2) in situ hybridization. RESULTS: A total of nine ENKTL were identified (mean age of 48 years and male-to-female ratio of 8:1). There were five nasal ENKTL, and the remaining four cases had extranasal involvement (palate, sub-mandibular gland, skin, and soft tissues of the ankle). The histopathology showed a lymphoid and pleomorphic proliferation characterized by images of angiocentrism. Strong and diffuse CD3 expression was observed in all cases. Tumor cells exhibited an expression of CD5 (two cases), CD8 (three cases), CD56 (six cases), CD57 (three cases), and Granzyme B (eight cases). All ENKTL cases were EBV-associated. Overall 5-year survival rate was 57%. Although six ENKTL were diagnosed at early clinical stages, the prognosis was unfavorable and associated with patient death in three cases. CONCLUSIONS: ENKTL are exceptional in Tunisia with unfavorable outcome. Histopathological diagnosis remains challenging in clinical practice. However, a careful histopathological examination combined with a correct interpretation of immunohistochemistry and in situ hybridization results refines the ENKTL diagnosis.