Dietary risk factors for nasopharyngeal carcinoma in Maghrebian countries

Abstract

North Africa is one of the major Nasopharyngeal Carcinoma (NPC) endemic regions. Specific food items unique to this area were implicated to be associated with NPC risk, but results were inconsistent. Here we have performed a large-scale case-control study in the Maghrebian population from Tunisia, Algeria and Morocco. From 2002 to 2005, interviews were conducted on 636 cases and 615 controls. Controls were hospitalized individuals from 15 non-cancer hospital departments, or friends and family members of non-NPC cancer subjects, matched by center, childhood household type (rural or urban), age and sex. Conditional logistic regression is used to evaluate the risk of factors. In results, consumption of rancid butter, rancid sheep fat and preserved meat not spicy (mainly quaddid) were associated with significantly increased risk of NPC, while consumption of cooked vegetables and industrial preserved fish was associated with reduced risk. Other foods such as fresh citrus fruits and spicy preserved meat (mainly osban) in childhood, industrial made olive condiments in adulthood, were marginally associated. In multivariate analyses, only rancid butter, rancid sheep fat and cooked vegetables were significantly associated with NPC. In regard to possible causative substances, our results implicate the involvement of butyric acid, a potential Epstein-Barr virus (EBV) activator. ' 2007 Wiley-Liss, Inc.

Cannabis, tobacco and domestic fumes intake are associated with nasopharyngeal carcinoma in North Africa

“…Details of demographic breakdown by sex, age, and study centre were presented earlier (Feng et al, 2007). In summary, there were no significant differences between cases and controls with regard to ethnic group, country, recruitment centre, or household type during childhood.…”

“…Details of the studied populations are described elsewhere (Feng et al, 2007). In brief, all incident cases diagnosed in 2001 -2004 in five hospitals were identified by clinicians in the oncology and radiotherapy departments, and were invited for interview.…”

“…Controls were hospitalised individuals from 15 non-cancer hospital departments (61%) or friends and family members of non-NPC cancer patients (39%), frequency-matched by centre, age, sex, and childhood household type (urban/rural). Hospitalised controls were recruited from selected departments (see Feng et al, 2007), in which diseases sharing risk factors with NPC were carefully excluded (i.e., ear, nose, and throat conditions; alcohol-and tobacco-related diseases; or potential HLA-related disorders such as autoimmune diseases). Among the individuals invited to participate (both cases and controls), more than 90% were successfully interviewed.…”

“…Conditional logistic regression with strata defined by sex and centre was used to evaluate the association of a specific factor with NPC risk, adjusting for age, SES variables (household type, lodging category, occupation and education level) and associated dietary factors (rancid butter, rancid sheep fat and cooked vegetables during adulthood) (Feng et al, 2007). Odds ratios (OR) and corresponding 95% confidence intervals (CI) were calculated.…”

“…Recently, we carried out a large multi-centric case -control study in Algeria, Morocco and Tunisia of genetic and environmental risk factors for NPC (Feng et al, 2007). In this study, we examined NPC risk in relation to tobacco, cannabis, domestic fumes and alcohol intake, taking into account the effects of associated dietary risk factors, socioeconomic status (SES) and other potential confounders; lifestyles specific to North Africa, such as local cooking practice facilities and local forms of tobacco intake were investigated in detail.…”