Two new class III G6PD variants [G6PD Tunis (c.920A>C: p.307Gln>Pro) and G6PD Nefza (c.968T>C: p.323 Leu>Pro)] and overview of the spectrum of mutations in Tunisia.

We screened 423 patients referred to our laboratory after hemolysis triggered by fava beans ingestion, neonatal jaundice or drug hemolysis. Others were asymptomatic but belonged to a family with a history of G6PD deficiency. The determination of enzymatic activity using spectrophotometric method, revealed 293 deficient (143 males and 150 females). The molecular analysis was performed by a combination of PCR-RFLP and DNA sequencing to characterize the mutations causing G6PD deficiency. 14 different genotypes have been identified : G6PD A(-) (376A>G;202G>A) (46.07%) and G6PD Med (33.10%) were the most common variants followed by G6PD Santamaria (5.80%), G6PD Kaiping (3.75%), the association [c.1311T and IVS11 93c] (3.75%), G6PD Chatham (2.04%), G6PD Aures (1.70%), G6PD A(-) Betica (0.68%), the association [ 376G;c.1311T;IVS11 93c] (0.68%), G6PD Malaga, G6PD Canton and G6PD Abeno respectively (0.34%). Two novel missense mutations were identified (c.920A>C: p.307Gln>Pro and c.968T>C: p.323 Leu>Pro). We designated these two class III variants as G6PD Tunis and G6PD Nefza. A mechanism which could account for the defective activity is discussed.

Microsatellite and single nucleotide polymorphisms in the ß-globin locus control region-hypersensitive Site 2: SPECIFICITY of Tunisian ßs chromosomes.

The diversity of sickle cell disease severity is attributed to several cis acting factors, among them the single nucleotide polymorphisms (SNPs) and (AT) rich region in the ß-locus control region (ß-LCR). This contains five DNase I hypersensitive sites (HS) located 6 to 22 kb upstream to the ϵ gene. The most important of these is the HS2 (5' ß-LCR-HS2), characterized by the presence of three different SNPs and a microsatellite region known to be in association with ß(S) chromosomes in various populations. The aim of this study was to present the molecular investigation of the 5' ß-LCR-HS2 site in normal and sickle cell disease individuals in order to determine if there is any correlation or specificity between these molecular markers, the ß(S) Tunisian chromosomes and phenotypical expression of sickle cell disease. One hundred and twenty-four chromosomes from Tunisian individuals (49 ß(S) carriers and 13 normal individuals) were screened by polymerase chain reaction (PCR) and sequencing for the polymorphic short tandem microsatellite repeats (AT)(X)N(12)(AT)(Y) and the three SNPs (rs7119428, rs9736333 and rs60240093) of the 5' ß-LCR-HS2. Twelve configurations of the microsatellite motif were found with an ancestral configuration elaborated by ClustalW software. Normal and mutated alleles were observed at the homozygous and heterozygous states for the three SNPs. Correlation between microsatellites and SNPs suggests that mutant SNP alleles were mainly associated, in the homozygous sickle cell disease phenotype, with the (AT)(8)N(12)GT(AT)(7) configuration, whereas, normal SNP alleles were associated with the (AT)(X)N(12)(AT)(11) configurations in normal ß(A) chromosomes. The correlation of these various configurations with Hb F expression was also investigated. The principal component analysis (PCA) showed the correlation between the homozygous sickle cell disease phenotype, mutated SNP alleles and the Benin microsatellite configuration (AT)(8)N(12)GT(AT)(7), which confirmed the specificity of this configuration to the ß(S) chromosomes. In addition, the observed high level of Hb F (14.6%) could play a protective role against Hb S to justify the modulation of sickle cell disease severity within the Benin haplotype compared to the other haplotypes. This study highlights the fact that the ß-LCR-HS2 could be a genetic marker to identify the ethnic Tunisian ß(S) chromosomes and facilitate the molecular diagnosis of sickle cell disease.

[Changes in serum lipids in patients with colorectal cancer]. / Variation du bilan lipidique chez des malades ayant un cancer colorectal.

AIM: To evaluate and assess disruptions of serum lipids at patients having a colorectal cancer. METHODS: Our prospective study interested 30 patients, from 26 to 93 year old, presenting a colorectal cancer confirmed histologically, examined during the period going from March 2003 to April 2004. Thirty healthy controls were examined in parallel. All patients undergo three blood samples respectively in preoperative, 48h and 6 months after surgical operation. The analyses carried out were determination of a total serum cholesterol, HDL (high density lipoprotéin) and LDL (low density lipoprotein) cholesterol, serum triglyceride and serum apoprotein (AI and B) RESULTS: We noticed a decrease of total serum cholesterol level in 43% of the cases associated to the reduction of the HDL and the LDL cholesterol in respectively 30% and 76% of cases. The mean values of total serum cholesterol, HDL and LDL cholesterol rates were significantly lower for patients compared to those of controls (p respectively : 0.001; 0.04 and 0.001). Moreover, the level of total serum cholesterol varied significantly with tumor localization ( p= 0,02). CONCLUSION: Serum lipid disruptions affect essentially total cholesterol, HDL and LDL cholesterol. It would be therefore interesting to evaluate their rate at the basal state in order to follow their evolution after treatment in colorectal cancer.

[Importance of biologic parameters in Helicobacter pylori gastritis: comparison with histological results]. / Intérêt de certains paramètres biologiques au cours de la gastrite à Helicobacter pylori: comparaison avec les résultats histologiques.

Helicobacter pylori (HP) chronic gastritis can lead to precursor stages of gastric cancer. New biological markers have been proposed to study the gastric mucosal state. We evaluate biological results in comparison with histological ones in a dyspeptic population. Forty nine dyspeptic patients underwent endoscopy with gastric biopsies for histological examination. Blood samples were obtained to measure levels of gastrin 17 (G17), pepsinogen 1 (PG1), pepsinogen 2 (PG2) and the rate of anti-HP IgG antibodies. Four patients have a healthy gastric mucosa and 45 have a gastritis (32 have a nonatrophic gastritis and 13 an atrophic one). An increase in the level of PG2 and a decrease of the PG1/PG2 ratio were noticed in the group of subjects with a nonatrophic gastritis compared to the healthy mucosa group. The decrease of the PG1/PG2 ratio was more important in the corpus atrophic gastritis group than in the antrum restricted atrophic gastritis one. In conclusion, in front of dyspeptic patients, we advice to practice in first intention the measurement of the serological level of G17, PG1, PG2 and anti-HP IgG antibodies.

[Importance of determination of C reactive protein (CRP), carcinoembryonic antigen (CEA) and lactic dehydrogenase (LDH) in colorectal cancer]. / Intérêt des dosages sériques de la protéine c réactive (crp), de l'antigène carcino embryonnaire (ace) et de la lacticodeshydrogenase (ldh) dans le cancer colorectal.

AIM: Evaluate and show the importance of CRP, ACE and LDH in colorectal cancer. METHODS: Our prospective study interested 30 patients, from 26 to 93 years old and present a colorectal cancer, confirmed histologically, during the period going from March 2003 to April 2004, and 30 healthy controls. A blood sample was collected from each patient respectively in preoperative, 48 hours before any treatment, and 6 months after surgical operation to measure serum LDH, CRP, and ACE. RESULTS: The mean serum of LDH, CRP and ACE values were significant higher in patients than those in controls (p respectively: 0,01; 0,04 et 0,01). Moreover, the level of three parameters varied significantly with stages of tumor. After follow up, we have noticed e normalisation of the mean of the level of LDH, CRP and ACE with favorable evolution. Analysis of survival at 2 years showers that survival is better in patients with normal value of CRP, ACE and LDH. CONCLUSION: CRP, LDH and ACE values have a great importance during follows up after colorectal cancer surgery.

Association of MICA-129 polymorphism with nasopharyngeal cancer risk in a Tunisian population.

Major histocompatibility complex (MHC) class I chain-related A (MICA) molecules mediate natural killer (NK) cell activation and T lymphocyte co-stimulation. A polymorphic methionine (met) to valine (val) variation at amino acid position 129 of the alpha2 heavy chain domain is in linkage disequilibrium with other allelic changes and seems to categorize MICA alleles into strong and weak binder of NKG2D receptor and thereby to influence effector cell function. We investigated here whether MICA-129 dimorphism is associated with susceptibility to/or resistance against developing nasopharyngeal cancer (NPC). DNA from 130 NPC patients and 180 healthy individuals from Tunisia were genotyped for MICA-129 variation. We found a higher frequency of MICA-129 val/val genotype in patients than in controls (corrected p value = 0.02) that could suggest a tumor escape mechanism because of failure to activate NK cells by MICA-129 val allele or absence of NK cell activation because of absence of MICA-129 met allele in individuals otherwise predisposed to viral/environmental factors.

Use of common seric tumor markers in patients with solid cancers.

Seric tumour markers (STM) are molecules that theoretically indicate the presence of malignancy, and used for monitoring response to therapy and early detection of relapse. This article describes the use and limitations of common SMT in patient with solid tumors. Excepting prostate specific antigen (PSA) and thyroglobulin, STM are not poorly sensitive or specific for screening and diagnosis of cancers. Alpha foetoprotein (AFP) is however used to screen hepatocellular carcinoma in high risk patients with suspect masses. Beta subunit of human chorionic gonadotrophin (beta-HCG) is frequently used for the diagnosis and management of gestational trophoblastic disease, while combined AFP and beta-HCG dosage is a good adjunct in the evaluation and treatment of non seminomatous germ cell tumors. PSA is used for screening and follow up of prostate cancer. Ca 125 is useful for evaluating pelvic masses in postmenopausal women and monitoring response to therapy in women with ovarian cancer, while Ca 15 3 is used to follow response to therapy in patients with breast cancer.

[Seric soluble interleukin-2 receptor alpha in nasopharyngeal carcinoma in Tunisia. Prospective study about 45 cases]. / Taux serique du recepteur alpha soluble de l'interleukine 2 dans le carcinome du nasopharynx en Tunisie. Etude prospective sur 45 cas.

BACKGROUND: Soluble interleukin-2 receptor alpha (slL-2Ralpha) is a well-known indicator of T-cell activation noted to be increasing in nasopharyngeal cancer. The aims of this study were to evaluate the importance of the use of this marker in nasopharyngeal carcinoma. METHODS: Our prospective study interested 45 patients (35M/10F) with a mean age of 49 years (15 to 78), presenting a nasopharyngeal carcinoma histologically confirmed and 61 healthy controls. A blood sample was collected from each patient before any treatment, as well as controls to measure sIL-2Ralpha by immunoenzymatic assay. According to the disease status after a period of follow-up ranging from three to 22 months (median 12 months), patients were divided into two groups: The remission group (n=28) represented those with favourable evolution and a second group of 15 patients with unfavourable evolution (2 death, 4 cases of persistent primary disease and 9 patients with distance metastasis). 2 patients were lost to follow-up. RESULTS: serum sIL-2Ralpha levels were significantly higher in patients vs healthy controls (p < 0.0001). The serum levels correlated with the stage T of NPC (p = 0.01). Patients having a favourable evolution have lower sIL-2Ralpha levels before treatment vs those with unfavourable evolution without statistical difference. CONCLUSION: Measurement of serum sIL-2Ralpha provides a good estimation of the nasopharyngeal tumor burden. The usefulness of this marker as a parameter to predict prognosis in NPC should be examined further.

[Biological investigation of thyroid cancer]. / Exploration biologique du cancer de la thyroide.

Thyroid carcinomas represent the most common endocrine malignancy, and several biological markers are proposed according to the different types of this cancer: for papillary cancer, thyroglobulin constitutes an excellent prognostic factor and rearrangements of ret oncogene can be useful in diagnosis. In sporadic medullary carcinoma, calcitonin is a diagnosis marker of choice, and coupled with ACE, can prevent relapse. Regarding familial medullary carcinoma, mutation screening in ret oncogene leads to early detection of new cases.

Association between rs267196 and rs267201 of BMP6 gene and osteonecrosis among sickle cell aneamia patients.

AIMS: The skeletal manifestations of sickle cell disease are the result of changes in bone and bone marrow caused by chronic tissue hypoxia that is exacerbated by episodic occlusion of the microcirculation by the abnormal sickle cells. Furthermore, the occurrence of osteonecrosis is under the control of some modifier gene. BMP6 (Bone morphogenetic protein) has been reported as associated with osteonecrosis in sickle cell anemia (SCA). Herein, we intend to study the impact of rs267196, rs267201, rs408505 and rs449853 of BMP6 gene in the occurrence of osteonecrosis among sickle cell patients in Tunisia. METHODS: Our study involved 100 SCA patients among whom 19 have osteonecrosis of the head of the femur. The latter polymorphisms of BMP6 gene were analyzed for all subjects by PCR/sequencing. To test for trait association with the candidate SNPs, genotype and allele frequencies between cases (osteonecrosis group) and controls (non-osteonecrosis group) were compared using Pearson's chi_square test with a significance threshold of P<0.05 (compare 2, version 1.02). RESULTS: Our findings showed that the patients carried genotype TA of rs 267196 and genotype AG of rs267201 present a high risk factor for developing osteonecrosis RR=1.317 and RR=1.3 respectively. The results showed a significant association between the alleles A of rs 267196 and G of rs267201 and osteonecrosis P=0.0023; RR=2.42 and P=0.041; RR=2.24 respectively. Interestingly, SCA patients with the combined genotype TA/AG were found to be at higher risk of developing osteonecrosis (P=0.009). As for rs408505 and rs449853 of BMP6 gene no significant association was found among SCA patients.

Polymorphisms in oxidative stress-related genes are associated with nasopharyngeal carcinoma susceptibility.

Nasopharyngeal carcinoma (NPC) is a complex multifactorial disorder involving both genetic and environmental factors. Polymorphisms of genes encoding nitric oxide synthase (NOS) and antioxidant glutathione-S transferases (GSTs) have been associated with various tumors. We examined the combined role of NOS3, NOS2 and GST polymorphisms in NPC risk in Tunisians. We found that NOS3−786C allele and −786 CC genotype, NOS3+894T allele and +894 GT+TT genotypes, NOS2−277 G allele and −277 GG genotype, and GSTT1 del/del genotype, are more prevalent in NPC patients as compared to healthy controls. Our results suggest that genetically driven dysfunction in red­ox stress pathway could augment the risk in NPC-susceptible individuals.

[Contribution of serum Cyfra 21-1 in nasopharyngeal carcinoma in Tunisia]. / Apport du dosage sérique du Cyfra 21-1 dans le cancer du cavum en Tunisie.

Cyfra 21-1 is a recognised marker for epidermoid lung and head and neck carcinomas oriented to the cytokeratin 19 that is expressed particularly in malignant epithelial cells. The aims of this study were to evaluate the importance of the use of this marker in nasopharyngeal carcinoma (NPC). Our prospective study interested 41 patients (33M/8F) with a mean age of 44 years (13 to 70) with 8 of them aged less than 30 years, presenting a nasopharyngeal carcinoma histologically confirmed from September 1999 to March 2000 and 45 healthy controls without evidence neoplasm. Undifferentiated forms represent 90.2% of cases and lesions are staged T2, T3 and T4 in 2.4%, 36.6% and 61% of cases, while N1, N2 and N3 represent 9.8%, 26.8% and 41.5% of cases. A blood sample was collected from each patient and control before any treatment, as well as controls to measure Cyfra 21-1 by immunoenzymatic assay, 2 groups of patients were selected after a period varying from 4 to 37 months with a median of 29 months: 27 patients with favourable evolution (without evidence of disease after initial treatment), 12 patients with non favourable evolution (1 death, 2 cases of loco-regional relapse and 9 patients with metastatic disease). 2 patients were lost to follow-up. The results showed that the mean serum Cyfra 21-1 values were significantly higher in patients with NPC than those in controls (p = 0.001). A significant correlation was found between the serum Cyfra 21-1 level before treatment and the clinical outcome of patients (p = 0.0009). Patients having a favourable evolution have the lowest level. Seric level of Cyfra 21-1 at diagnosis of NPC may play a predictive role to evaluate the risk of metastatic disease and prognosis.

[Bioclinical correlations in bony metastases. Results of a prospective study. 60 cases]. / Corrélations biocliniques dans les métastases osseuses. Résultats d'une étude prospective. A propos de 60 cas.

UNLABELLED: Our objective is to compare clinical and biological presentation of patients with bone metastatic disease. PATIENTS AND METHODS: We collected prospectively 60 patients (adults and children) with proven bone metastasis. Tumors are mainly breast cancer (25/60) or nasopharyngeal carcinoma (8/60). All 8 children presented all with abdominal neuroblastoma. Bone lesions are lytic in 85% of cases. ALP and LDH seem to be sensitive markers for bone mestatasis with 75% and 80% pathologic rates. The highest rates have been observed in patients with multiple bones lesions (> 8) and painful metastases (more than 7 in the VAS). The median survival was 8 months (3 to 54). CONCLUSION: Even conventional, some biochemical markers as ALP and LDH remain useful in the diagnosis and prognosis in patients with proven bone metastasis.

Early complication in Sickle Cell Anemia children due to A(TA)_n TAA polymorphism at the promoter of UGT1A1 gene.

AIM: To determine the implication of the polymorphism namely A(TA)nTAA of UGT1A1 in lithogenesis for the first time in Tunisia among sickle cell anemia (SCA) children patients. MATERIAL AND METHODS: Our study was performed in 2010 and it involved 76 subjects chosen as control group characterized with normal hemoglobin status and presence of cholelithiasis and 102 SCA pediatric patients among whom 52 have cholelithiasis. We analyzed the polymorphism A(TA)_{n} TAA at the UGT1A1 promoter and the relationships between the various A(TA)_{n} TAA genotypes and alleles and bilirubin levels and occurrence of cholelithiasis. RESULTS AND DISCUSSION: The repartition of genotypes found according to serum bilirubin level shows a significant association between genotypes carried variant (TA)_{7} and hyperbilirubinemia (p< 0.05). We demonstrated the association of two genotypes with gallstones formation among SCA children patients: (TA)_{7}/(TA)_{7} and (TA)_{7}/(TA)_{8} with p=8.1 × 10^{ - 8} and p=0.01 respectively. (TA)_{7} and (TA)_{8} allele variants act as a risk factor for early gallstones formation in SCA patients with p=5.8 × 10^{ -9} and p=0.01 respectively. As for the control group only the genotype (TA)_{7}/(TA)_{7} presented a risk factor for gallstones formation. CONCLUSION: The novelty of this report is that it is the first time that a similar study was made on the Tunisian children sickle cell population and that the results show a clear association of (TA)_{7} variant in early gallstones formation in Tunisian SCA children. Interestingly our findings highlighted the association of (TA)_{8} variant as well, which was not found in previous studies.

Early complication in sickle cell anemia children due to A(TA)nTAA polymorphism at the promoter of UGT1A1 gene.

AIM: To determine the implication of the polymorphism, namely, A(TA)nTAA of UGT1A1 in lithogenesis for the first time in Tunisia among sickle cell anemia (SCA) children patients. MATERIAL AND METHODS: Our study was performed in 2010 and it involved 76 subjects chosen as control group characterized with normal hemoglobin status and presence of cholelithiasis and 102 SCA pediatric patients among whom 52 have cholelithiasis. We analyzed the polymorphism A(TA)nTAA at the UGT1A1 promoter and the relationships between the various A(TA)nTAA genotypes and alleles and bilirubin levels and occurrence of cholelithiasis. RESULTS AND DISCUSSION: The repartition of genotypes found according to serum bilirubin level shows a significant association between genotypes carrying variant (TA)7 and hyperbilirubinemia (P < 0.05). We demonstrated the association of two genotypes with gallstones formation among SCA children patients: (TA)7/(TA)7 and (TA)7/(TA)8 with P = 8.1 × 10⁻8 and P = 0.01, respectively. (TA)7 and (TA)8 allele variants act as a risk factor for early gallstones formation in SCA patients with P = 5.8 × 10⁻9 and P = 0.01, respectively. As for the control group only the genotype (TA)7/(TA)7 presented a risk factor for gallstones formation. CONCLUSION: The novelty of this report is that it is the first time that a similar study was made on the Tunisian children sickle cell population and that the results show a clear association of (TA)7 variant in early gallstones formation in Tunisian SCA children. Interestingly our findings highlighted the association of (TA)8 variant as well, which was not found in previous studies.

Implication of genetic variation at the promoter and exon1 of UGT1A1 in occurrence of cholelithiasis in Tunisia.

Bilirubin is conjugated with glucoronic acid in the liver by UDP-glucuronosyltransferase 1A1 (UGT1A1). Polymorphisms at the promoter region or exon1 of UGT1A1 gene result in unconjugated hyperbilirubinemia and could be at the origin of gallstone formation. The purpose of this study is to determine whether polymorphisms in the promoter area and exon 1 of UGT1A1 can be considered as a risk factor for lithogenesis. Our study involved 76 patients with cholelithiasis as well as 141 unaffected subjects. For each subject an analysis of the bilirubin parameters was performed. We screened genetic variation in the promoter and exon1 UGT1A1 namely the A (TA) nTAA and the six following SNPs: 44T>G, 101C>A, 115C>G, 145C>T, 211G>A and 222 C>A by PCR/sequencing. Our findings show that subjects with (TA)(7) or (TA)(8) variant in their genotypes are associated with high bilirubin level. Furthermore, the comparison between patients and controls according to A(TA)nTAA variation demonstrated that (TA)(6)/(TA)(7) and (TA)(7)/(TA)(7) genotype and (TA)(7) and (TA)(8) alleles were significantly associated with an increased risk of gallstone diseases p=0.0017, p= 6.1 10(-6), p=1.5 10(-6) and p=0.025 respectively. However, polymorphisms in exon1 were normal in all studied subjects except for the 211G>A which appears to be associated with a protective effect p=7.910(-9); OR=0.03, CI95% (0.001-0.158).

[Erythropoietin levels in perioperative period in cancer patients]. / Variation de l'érythropoïétine sérique chez des malades opérés en chirurgie carcinologique.

Anemia is frequent in cancer patients, is the result of decreased erythropoietin production. In fact in cancer, alteration of immune system alters iron metabolism and inhibits erythropoietin production. In this study we proposed to determine the profile of erythropoietin secretion in anaemic cancer patients in the pre and postoperative period. Our prospective study from January to March 2005 included 41 anemic cancer patients from 30 to 79 years old and 31 healthy individuals with iron deficiency anemia. A measure of erythropoietin, CRP, ferritin, iron levels and hemoglobin were released in healthy individuals and in cancer patients in preoperative period (J0) and postoperative period (J3, J8, J21). In preoperative period, the increase of serum erythropoietin was significantly lower in patients than in healthy individuals. In postoperative period, the levels of erythropoietin at J3 and hemoglobin's at J8 and J21 were significantly higher than in preoperative period (J0) (p < 0.05). In conclusion, despite the presence of inflammatory syndrome caused by surgery, cancer patients with anaemia increase their erythropoietin production in immediate postoperative period.

[Genetic polymorphism of gluthation-S transferases and N-acetyl transferases 2 and nasopharyngeal carcinoma: the Tunisia experience]. / Polymorphisme génétique des enzymes gluthation-S transférases et N-acétyl-transférases 2 dans le cancer du nasopharynx en Tunisie.

Interindividual differences observed in the metabolism of xenobiotics have been attributed to the genetic polymorphism of genes, which code for enzymes involved in detoxification. This genetic variability seems to be associated with the individual's susceptibility to certain cancers, including nasopharyngeal carcinoma. In this study, we have investigated the genotypic frequencies of DNA polymorphisms of two detoxification's genes: the gluthatione-S-transferase (GST) and the N-acetyl transferase 2 (NAT2). The study has included 45 patients with nasopharyngeal carcinoma compared to 100 healthy Tunisian controls. The presence of the GSTM1 null and GSTT1 null polymorphism was screened by using a multiplex PCR procedure. A PCR-RFLP method was used to detect polymorphism for the most common alleles of the NAT2 gene. Allelic frequencies between the two groups were compared using a chi2 test and odds ratio with 95% confidence intervals were calculated. The results indicate that the genotypic frequency of GSTM10/0 between controls and patients was significantly different. This genotype confers an increased risk of nasopharyngeal carcinoma (Odds Ratio = 2.12, [0.64-4.7]). However, genotypic frequencies of NAT2*6/NAT2*6 were significantly higher in the group of nasopharyngeal carcinoma patients. The calculated Odds Ratio showed an association between this genotype and nasopharyngeal carcinoma. In conclusion, the increase of nasopharyngeal carcinoma risk in Tunisia seems to be associated with GSTM10/0 and NAT2*6/6 genotype.

[Nasopharyngeal carcinoma in Tunisian children: retrospective epidemiological, clinical and biological study about 48 cases]. / Le carcinome du nasopharynx chez l'enfant tunisien: étude rétrospective épidémiologique, clinique et biologique, à propos de 48 cas.

OBJECTIVE: Report epidemiological, clinical and biological aspects of nasopharyngeal carcinoma in Tunisian children. PATIENTS AND METHODS: Our retrospective study from 1994 to 2001 included all children treated for nasopharyngeal carcinoma in the Salah Azaïz Cancer Institute of Tunis. Initial investigation consisted of ENT and general examination, nasopharyngeal CT-scan, abdominal echography, chest X-ray and bone scintigraphy. Biological markers included blood-count, erythrocytes sedimentation and serum lactic dehydrogenase. All children received neoadjuvant chemotherapy (adriamycin, cisplatin) and irradiation therapy. RESULTS: There were 48 children with a median age of 13,7 years and a sex ratio of 1,4 (28/20). Lesions are staged T2, T3 and T4 in 2,1 %, 18,7% and 79,2% of cases. All patients have cervical palpable nodes at diagnosis classified as N1 (8,3%), N2 (33.3%) and N3 (58.3%). A significant correlation was found between serum lactic dehydrogenase and the N stage (p = 0.02). After follow up, recurrence of disease was noted for three children, persistent disease for two children and metastatic disease in five cases. The overall and relapse free survival at 5 years were 79.1% and 68.9% respectively. Patients aged 13 or lower had poorer 5 overall survival rate (72.3%) than older age group (84.2%).