Genetic variations in CYP2A6, CYP2E1, GSTM1, GSTT1 genes and the risk of Nasopharyngeal carcinoma in North African population

BACKGROUND

Nasopharyngeal carcinoma (NPC) is a multifactorial malignancy associated with both genetic and environmental factors. Polymorphic deletions of the phase I and phase II genes involved in the detoxification of potential carcinogens may be a risk factor for nasopharyngeal carcinoma. In this study, we investigated the relationship between CYP2E1 (rs3813867), CYP2A6, GSTM1(rs1183423000) and GSTT1(rs1601993659) gene variations and NPC risk in North African countries with the highest incidence of NPC (Morocco, Algeria and Tunisia). and the evaluation of the potential use of these variants as potential biomarkers for NPC management.

METHODS

A total of 600 NPC cases and 545 controls frequency-matched on ethnicity, sex, age and childhood household type, were recruited from three North African countries (Morocco, Algeria and Tunisia) and analysed. Genotyping of CYP2A6 and CYP2E1(rs3813867) was performed by polymerase chain reaction restriction (PCR)-fragment length polymorphism (RFLP) analysis and the GSTM1 (rs1183423000) and GSTT1(rs1601993659) genetic variations were evaluated using the PCR technique.

RESULTS

The genotype distributions of CYP2E1(rs3813867), CYP2A6, GSTM1(rs1183423000) and GSTT1(rs1601993659) genotypes did not differ significantly among NPC cases and controls (p > 0.05). Furthermore, our data did not reveal any association with smoking and the studied variants, even when the samples were stratified by the duration period of smoking.

CONCLUSION

In this large studied North African population, our findings suggest that the functional CYP2E1, CYP2A6, GSTM1 and GSTT1 variations did not influence NPC susceptibility.

Risk factors for inflammatory and non-inflammatory breast cancer in North Africa

PURPOSE

Studies of the etiology of inflammatory breast cancer (IBC), a rare but aggressive breast cancer, have been hampered by limited risk factor information. We extend previous studies by evaluating a broader range of risk factors.

METHODS

Between 2009 and 2015, we conducted a case-control study of IBC at six centers in Egypt, Tunisia, and Morocco; enrolled were 267 IBC cases and for comparison 274 non-IBC cases and 275 controls, both matched on age and geographic area to the IBC cases. We administered questionnaires and collected anthropometric measurements for all study subjects. We used multiple imputation methods to account for missing values and calculated odds ratios (ORs) and 95% confidence intervals (CIs) using polytomous logistic regression comparing each of the two case groups to the controls, with statistical tests for the difference between the coefficients for the two case groups.

RESULTS

After multivariable adjustment, a livebirth within the previous 2 years (OR 4.6; 95% CI 1.8 to 11.7) and diabetes (OR 1.8; 95% CI 1.1 to 3.0) were associated with increased risk of IBC, but not non-IBC (OR 0.9; 95% CI 0.3 to 2.5 and OR 0.9; 95% CI 0.5 to 1.6 for livebirth and diabetes, respectively). A family history of breast cancer, inflammatory-like breast problems, breast trauma, and low socioeconomic status were associated with increased risk of both tumor types.

CONCLUSIONS

We identified novel risk factors for IBC and non-IBC, some of which preferentially increased risk of IBC compared to non-IBC. Upon confirmation, these findings could help illuminate the etiology and aid in prevention of this aggressive cancer.

Expression Profile of Survivin and p16 in Laryngeal Squamous Cell Carcinoma: Contribution of Tunisian Patients

The objective of this study was to evaluate the expression of survivin and p16 in laryngeal squamous cell carcinoma (LSCC) in order to analyze their pathogenesis and prognostic significance in Tunisian patients. A total of 70 patients with LSCC collected at the Salah Azaiez Cancer Institute of Tunis were retrospectively evaluated. Expression of survivin and p16 was examined using immunohistochemistry, and the correlations with clinicopathological parameters, overall survival (OS), and disease-free survival (DFS) were statistically evaluated. The positive expression of survivin and p16 were found in 58.6% and 51.43% of LSCC cases, respectively. The p16 expression was not associated with either clinical parameters or patient survival, whereas there was a strong correlation of survivin expression and lymph node metastases (P = .002), alcohol consumption (P = .024), and therapeutic protocol (with or without chemotherapy; P = .001). Kaplan-Meier survival curves showed that patients with LSCC having positive survivin expression have shorter OS (P = .026) and shorter DFS (P = .01) than those with negative expression. Positive survivin expression was also correlated with high recurrence rate (P = .014). Therefore, survivin is a poor prognostic marker for LSCC but the therapeutic protocol remains, in multivariate study, the most decisive for the OS and DFS of our patients with P < .01. Our data indicated that, in Tunisian laryngeal squamous cell carcinoma, survivin expression is associated with unfavorable outcomes and represents a predictor marker of recurrence and chemoresistance. However, p16 expression has no prognosis value.

Expression Profile of Survivin and p16 in Laryngeal Squamous Cell Carcinoma: Contribution of Tunisian Patients

The objective of this study was to evaluate the expression of survivin and p16 in laryngeal squamous cell carcinoma (LSCC) in order to analyze their pathogenesis and prognostic significance in Tunisian patients. A total of 70 patients with LSCC collected at the Salah Azaiez Cancer Institute of Tunis were retrospectively evaluated. Expression of survivin and p16 was examined using immunohistochemistry, and the correlations with clinicopathological parameters, overall survival (OS), and disease-free survival (DFS) were statistically evaluated. The positive expression of survivin and p16 were found in 58.6% and 51.43% of LSCC cases, respectively. The p16 expression was not associated with either clinical parameters or patient survival, whereas there was a strong correlation of survivin expression and lymph node metastases (P = .002), alcohol consumption (P = .024), and therapeutic protocol (with or without chemotherapy; P = .001). Kaplan-Meier survival curves showed that patients with LSCC having positive survivin expression have shorter OS (P = .026) and shorter DFS (P = .01) than those with negative expression. Positive survivin expression was also correlated with high recurrence rate (P = .014). Therefore, survivin is a poor prognostic marker for LSCC but the therapeutic protocol remains, in multivariate study, the most decisive for the OS and DFS of our patients with P < .01. Our data indicated that, in Tunisian laryngeal squamous cell carcinoma, survivin expression is associated with unfavorable outcomes and represents a predictor marker of recurrence and chemoresistance. However, p16 expression has no prognosis value.

Multiple Primary Cancers in North Tunisia, 2000 - 2009

Background and Objective: To evaluate and report the frequency, epidemiologic and anatomic - clinical features of patients who developed MPM from the data of North Tunisia Cancer Registry, during the period 2000-2009.Materials and methods: From a population of 53757 new patients of the North Tunisia National Cancer Registry database presenting new cases of cancers during the period 2000-2009 in North Tunisia, we collected and analyzed those with MPMTs. We used for MPMT the international IARC diagnosis criteria are published in ICD-O Third Edition. Results: In the 53757 new cancer cases registered from 2000-2009, we collected 528 cases (1.0%) of MPM. Mean age at diagnosis of the 1st cancer was 61 years (22-99) and sex-ratio at 1.08 (275M/253F) while mean age at the 2nd cancer diagnosis was 62 years(29 to 99). Among the 528 cases, the most frequent 1 st cancer site was breast in females (147 pts, 58.1%) and urinary tract for males (56 patients, 20.4%). In the 528 MPM cases, 321 (60.8%) were synchronous and 207 cases (39.2%) were metachronous tumors. The median time from 1 st to 2 nd cancer was 1.98 months (range 0-140). The most associated 1 st -2 nd cancer sites were breast in 110 patients (43.3%) in females and for males' urinary tract -prostate cancers (45 patients, 16.3%). Conclusions: The coexistence of a synchronous or metachronous MPM is possible and have to be considered during pretreatment evaluation. A close follow-up should be recommended to detect second malignancies in patients treated for a 1 st cancer.  

Joint effect of smoking and NQO1 C609T polymorphism on undifferentiated nasopharyngeal carcinoma risk in a North African population

BACKGROUND

Nasopharyngeal carcinoma (NPC) has a higher incidence in North Africa than in most parts of the world. In addition to environmental factors such as Epstein-Barr virus infection and chemical carcinogen exposure, genetic susceptibility has been reported to play a key role in the development of NPC. NAD(P)H: quinone oxidoreductase 1 is a cytosolic enzyme that protects cells from oxidative damage. A C to T transition at position 609 in the NQO1 gene (OMIM: 125860) has been shown to alter the enzymatic activity of the enzyme and has been associated with increased risk to several cancers. This study investigates for the first time the effect of this polymorphism on NPC susceptibility in a North African population.

METHODS

The NQO1 C609T polymorphism was genotyped using PCR-RFLP in 392 NPC cases and 365 controls from Morocco, Algeria, and Tunisia.

RESULTS

The allele frequencies and distributions of genotypes did not differ between cases and controls (p > 0.05). When stratifying according to smoking status, we observed two-fold higher NPC risk in ever-smokers carrying the CT or TT genotype. Multiple logistic regression analysis revealed that there was a significant interaction between T allele and smoking status (OR = 1.95, 95% CI = 1.20-3.19; interaction p = 0.007).

CONCLUSION

In this North African population, the functional NQO1 polymorphism was associated with a significantly higher risk of NPC among smokers and did not affect the risk among nonsmokers.

No association between TGF-β1 polymorphisms and risk of nasopharyngeal carcinoma in a large North African case-control study

Background

Genetic susceptibility plays a key role in the development of nasopharyngeal carcinoma (NPC) and in fact the disease presents with an unusually high incidence in certain regions of the world like North Africa. We investigated the association between polymorphism of the Transforming growth factor-β1 (TGF-β1) and risk of NPC in North Africa. TGF-β1 is a multifunctional cytokine that acts as both a tumor suppressor and a stimulator of cancer development; it has been shown to influence risk of numerous other carcinomas including lung, breast and prostate cancer.

Methods

TGF-β1 polymorphisms C-509T and T869C were studied in a large North African sample of 384 NPC cases and 361 controls, matched for age, sex and urban or rural residence in childhood. Genotypes were determined using polymerase chain reaction–restriction fragment length polymorphism.

Results

No association was observed between individual single nucleotide polymorphisms or their haplotypes and NPC susceptibility (for TGF-β1 C-509T: OR = 0.74; 95 % CI 0.46 − 1.18; for TGF-β1 T869C: OR = 0.86; 95 % CI 0.56 − 1.31), even when the samples were stratified by age, gender and TNM stage.

Conclusion

Contrary to what has been observed in Asian samples, in our North African sample, the TGF-β1 C-509T and T869C polymorphisms did not substantially influence NPC susceptibility.

Electronic supplementary material

The online version of this article (doi:10.1186/s12881-016-0337-8) contains supplementary material, which is available to authorized users.

[Evaluation of non-compliance of transfusion requests of packed red blood cells]

BACKGROUND

Despite legislative acts develloped, many deficiencies were identified in blood requests at the National Blood TransfusionCenter impedding board and blood safety.

AIM

to evaluate the conformity of the different topics of packed red blood cells requests to the legislation.

METHODS

Our study was prospective descriptive lasting six months (March-August 2011). It assessed all packed red blood cells requests which reached the national blood transfusion center.

RESULTS

16064 packed red blood cells requests from 21 public institutions and 28 private institutions were studied. There was different deficiencies in each item.The absence of birth date in 67.18% of request represented the largest non-compliance within administrative information. A predominance of shortcomings related to transfusion and obstetric history was recorded for clinical information with absence of date of the last transfusion in 91.72% cases, lack of accuracy of any previous transfusion reactions in 88.63% cases and absence of the number of previous pregnancies in 93.15% of transfusion requests prescribed to women. Non-conformities related to the prescribing physician concerned mainly the phone number which was absent in 55.82% of cases.

CONCLUSIONS

This study revealed a significant lack of awareness of physicians in relation to the law governing transfusion. It is therefore essential to develop training for prescribers to improve transfusion safety.

Assessment of diagnosis of inflammatory breast cancer cases at two cancer centers in Egypt and Tunisia

The diagnosis of inflammatory breast cancer (IBC) is largely clinical and therefore inherently somewhat subjective. The objective of this study was to evaluate the diagnosis of IBC at two centers in North Africa where a higher proportion of breast cancer is diagnosed as IBC than in the United States (U.S.). Physicians prospectively enrolled suspected IBC cases at the National Cancer Institute (NCI) - Cairo, Egypt, and the Institut Salah Azaiz (ISA), Tunisia, recorded extent and duration of signs/symptoms of IBC on standardized forms, and took digital photographs of the breast. After second-level review at study hospitals, photographs and clinical information for confirmed IBC cases were reviewed by two U.S. oncologists. We calculated percent agreement between study hospital and U.S. oncologist diagnoses. Among cases confirmed by at least one U.S. oncologist, we calculated median extent and duration of signs and Spearman correlations. At least one U.S. oncologist confirmed the IBC diagnosis for 69% (39/50) of cases with photographs at the NCI-Cairo and 88% (21/24) of cases at the ISA. All confirmed cases had at least one sign of IBC (erythema, edema, peau d'orange) that covered at least one-third of the breast. The median duration of signs ranged from 1 to 3 months; extent and duration of signs were not statistically significantly correlated. From the above-mentioned outcomes, it can be concluded that the diagnosis of a substantial proportion of IBC cases is unambiguous, but a subset is difficult to distinguish from other types of locally advanced breast cancer. Among confirmed cases, the extent of signs was not related to delay in diagnosis.

XRCC1 and hOGG1 genes and risk of nasopharyngeal carcinoma in North African countries

Although genetic susceptibility to nasopharyngeal carcinoma (NPC) has been recognized for a long time, little is known about the responsible genes. X-Ray repair cross-complementing protein 1 (XRCC1) and human 8-oxo-guanine glycosylase 1 (hOGG1) genes are involved in deoxyribonucleic acid (DNA) repair and were found associated with NPC risk in three Asian case-control studies. The objective of the present study was to test these genes in a sample from North Africa, one of the major NPC endemic regions in the world. Three single nucleotide polymorphisms (SNPs) in the XRCC1 gene and one SNP in the hOGG1 gene were genotyped in 598 NPC cases from Morocco, Algeria, and Tunisia and 545 controls frequency matched by recruitment center, age, sex, and urban/rural household. The genotype and allelic distributions for the hOGG1 (326)Ser/Cys SNP and for the XRCC1 (399)Arg/Trp, (280)Arg/His, and (194)Arg/Trp SNPs did not differ significantly among NPC cases and controls. The XRCC1 (194)Trp allele frequency was significantly lower in the North African population than in Asian population (f = 0.04 vs. 0.31 in Cantonese Chinese and 0.21 Han Chinese). The hOGG1 (326)Ser allele frequency was significantly higher in the North African population (f = 0.73) than in Asian populations (f = 0.39 in Taiwanese). The results of the present study obtained from a large sample indicate that the XRCC1 and hOGG1 genes are unlikely to play a role in the susceptibility to NPC in North Africans. Our results do not corroborate those found in Asian population on smaller samples.

Dietary risk factors for nasopharyngeal carcinoma in Maghrebian countries

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.

Risk of lung cancer and past use of cannabis in Tunisia

The association between the use of cannabis and the risk of lung cancer is unclear. A hospital-based case-control study was conducted among men in Tunisia and included 149 incident lung cancer cases and 188 controls. Tobacco smoking was significantly associated with an increased risk of lung cancer with odds ratios increasing linearly (p for trend < 0.0001) from 3.9 (95% confidence interval [CI], 1.4-10.9) for former smokers to 17.1 (95% CI: 6.3-46.3) among current smokers who had smoked for >35 years. The odds ratio for the past use of cannabis and lung cancer was 4.1 (95% CI: 1.9-9.0) after adjustment for age, tobacco use, and occupational exposures. No clear dose-response relationship was observed between the risk of lung cancer and the intensity or duration of cannabis use. This study suggests that smoking cannabis may be a risk factor for lung cancer.