Possibility of the use of serological method for the determination of immunoglobuline a antibody against early antigene of Epstein-Barr virus as a marker in the diagnosis of nasopharyngeal tumors

Risk factors for the occurrence of undifferentiated carcinoma of nasopharyngeal type: A case-control study

Introduction. The incidence rate of nasopharyngeal carcinoma in Serbia is less than one per 100,000 citizens, which classifies it as a region with low incidence for this disease. Objective. The aim of this study was to test some hypotheses of the risk factors for undifferentiated carcinoma of nasopharyngeal type (UCNT) in the low incidence population. Methods. A case-control study was used for the research. The study included 45 cases with histopathological diagnosis of UCNT and 90 controls. Cases and the controls were individually matched by sex, age (?3 years), and place of residence (city-village). Data were gathered about sociodemographic characteristics, occupational exposure to harmful agents, habits, diet, personal history, and family history. In the analysis of the data, conditional univariate and multivariate logistic regression analyses were applied. Results. According to the results of multivariate logistic regression analysis UCNT was significantly positively associated with 'passive smoking' of tobacco in the family during childhood, frequent consumption of industrially manufactured food additives for enhancing flavour and frequent consumption of white bread. UCNT was significantly negatively associated with frequent consumption of margarine, olive oil and cornbread. Conclusion. In our low incidence population, an independent risk factor for the occurrence of UCNT was 'passive smoking' of tobacco in the family during childhood, use of industrially manufactured food with additives for enhancing flavour and consumption of white bread. Multicentric study enrolling a greater number of cases would be desirable.

Incidence of nasopharyngeal carcinoma in Belgrade during the period 1991-2005

Background/Aim. Nasopharyngeal carcinoma (NPC) is a relatively rare malignant disease, of which 80 000 individuals become ill around the world annually, which amounts to 0.7% of all carcinomas. The aim of this descriptive study was to analyze NPC incidence in Belgrade (the capital city of Serbia, with about 1.6 million inhabitants) during the period 1991-2005. Methods. In data analysis, crude rates age and sex specific rates, and standardized incidence rates were used. Standardization was performed by a direct method, using world population as the standard. Results. In Belgrade, during the observed 15-year-period, the number of new NPC patients totaled 118, of which 86 (72.9%) were male and 32 (27.1%) were female. The average standardized incidence rate for men was 0.52 per 100 000 and for women 0.16 per 100 000. In both sexes the incidence was very low before 40 years of age. In men, the greatest incidence rate of NPC was in the 50-59 years age group, and in women in those 60 and more years old. Furthermore, undifferentiated carcinoma of nasopharyngeal type was 3.6 times more often in comparison to squamous cell carcinoma. Conclusion. Belgrade belongs to a region with a low incidence rate of NPC. Further investigations are needed to explain higher frequency of undifferentiated carcinoma of nasopharyngeal type than squamous cell carcinoma.

[Significance of confirming Epstein-Barr virus nuclear antibody as tumor marker]

BACKGROUND/AIM

Study of the association between Epstein-Barr virus (EBV) and the tumors of the nasopharynx renders an opportunity to introduce causal treatment Already have been proven the anti-EBV (anti-Epstein-Barr nucleus antigene) antibodies in the blood serum of the patients infected with EBV, while over 91% of the patients with nasopharyngeal malignant tumors also have a detectable anti-EBV marker. The aim of this research was to determine if there were anti-EBV antibodies in the serum of the patients with the already verified nasopharyngeal malignant tumors, and, if there were, to determine the quantitative ratio to the values in the serum of the healthy controls.

METHODS

The study involved 74 individuals in the period from 1994-2001 divided into four groups: group A counting 11 patients with undifferentiated carcinome of nasopharyngeal type (UCNT); group B counting 25 patients with UCNT X-ray treated at least three years before the onset of the study; group C including 28 healthy subjecets (blood donors), and the group D with 10 patients with planocellular nasopharyngeal carcinoma. Serologic diagnostics of the patients serum was performed using the techniques of Reedman and Klein for the detection of anti-EBV antibodies in the serum.

RESULTS

The presence of the statistically significantly higher values of the mean geometric titer (MGT) of the anti-EBNA antibodies was determined in 36 patients with histologically verified UCNT as compared with the control groups including 10 patients with planocellular carcinomas of the nasopharynx and 28 blood donors. Presented were anti-EBNA titers with 95% confidence interval for any participants according to the Hoo clinical classification of nasopharyngeal tumors, as well as according to the fact if they had been radiotreated within the previous three years.

CONCLUSION

The results of this study confirm the conclusions of the recent literature on the possible etiopathogenesis of nasopharyngeal tumors and the use of viral anti-EBNA antibodies as viral markers in the diagnostics of UCNT diseases.