Esophageal Cancer : Epidemiological , Clinical and Histopathological Aspects over a 24-Years Period at Kamenge University Hospital , Bujumbura , Burundi

Aim: There were no data about esophageal cancer in Burundi. The aim of the study was to highlight the epidemiological, clinical and histopathological aspects of the esophageal cancer. Method: A retrospective study over a 24-years period (from January 1988 to December 2011) was carried out at Kamenge university hospital, including patients with esophageal cancer. The cases were selected on basis of the histological evidence of the cancer. Results: A total of 34 cases were retrieved and included for analysis. Among them, 24 patients (70.5%) were males. The esophageal cancer constituted 8.6% of digestive cancers over the period of the study. The average age was 50.9 years. It was revealed by dysphagia in 32 patients (94.1%) and was concomitantly metastatic in 12 patients. The squamous cell carcinoma was 30 cases (88.2%). 27 patients underwent a curative resection, but the outcome and prognosis were poor. In-hospital mortality and morbidity rates were respectively 8.8% and 17.7%. Conclusion: The present study showed evidence that the esophageal cancer in our country had the same characteristics and distribution as well as in developing countries. It had a poor prognosis and efforts had to be done in the early cancer detection.


Introduction
The esophageal cancer is a primary malignant tumor with a poor prognosis.Its incidence varies according to the regions worldwide.The main risk factors are tobacco addiction, alcohol abuse and Barrett's esophagus that constitute a precancerous lesion associated with the gastro-esophageal reflux disease (GERD) [1] [2].The esophageal cancer problem has also been investigated at the cellular and immunological levels and mass cytological surveys allow many cases of early cancer to be detected and treated [3].Particularly in Sub-Saharan Africa, the esophageal cancer constitutes a great problem of public health for it is almost diagnosed at the tardy stage [4]- [6].
In Burundi, data about the esophageal cancer are missing.Indeed, there is not any cancer registry in the country.In addition, there is not so far any national policy to regulate tobacco and alcohol consumption despite that they constitute risk factors of a number of diseases including esophageal cancer.Also, people have traditionally subscribed to the belief that alcohol is a social link and its abuse becomes common.GERD is also frequent, about 35% in Burundi [7] [8].All these facts may contribute to increase the incidence of this type of cancer.So far, there has been no study concerning the esophageal cancer in Burundi.Thus, it seems relevant to carry out a first study designed to highlight the epidemiological, clinical and histopathological aspects of the esophageal cancer over a 24 years period.

Patients and Method
Site of the study: The study was carried out at Kamenge university hospital, the public and national tertiary referral hospital, with a capacity of 2275 admissions per year in the department of surgery.It is also the one hospital with a histopathological laboratory in Burundi.
Study design: A retrospective study over a 24-years period, designed to highlight the age, sex, clinical features, therapeutic approaches and histopathological subtypes of patients with esophageal cancer in Kamenge university hospital.The study population consisted of all patients attending medical care's at Kamenge university hospital since January 1988 to December 2011 for esophageal cancer.We included only patients with esophageal cancer diagnosed on basis of the histological evidence.Cases of esophageal cancer that have been histologically confirmed were retrieved from medical files and included for the study analysis.Patients with histological data missing or data outliers were excluded.Epidemiological variables like age, sex, and clinical features, therapeutic approaches and histopathological subtypes were collected initially in a specialized data collection form.Data management and analysis were performed using the statistical package for social sciences (SPSS) 10.0 for window version.Proportions are given with their confidence interval 95% (CI); p value < 0.05 was considered as statistically significant.
Ethical consideration: The ethics committee of Kamenge university hospital approved the study.

Discussion
The present study is the first study in Burundi, highlighting the age, sex, clinical features, therapeutic approach and histopathological subtypes of the esophageal cancer.The Kamenge university hospital was the best situated center for such study.Indeed, it is the one public and national tertiary referral hospital with a histopathological laboratory in Burundi.In addition, there is no cancer registry in our country.Nevertheless, the single center aspect of the present study seems to be a weakness, but it was not possible to extend the study in other centers, as subjects were selected on the basis of the histopathological evidence of cancer.In fact, the single histopathological laboratory in Burundi is located in Kamenge university hospital.The limitation of this study is the common drawback associated with the use of a retrospective method.Consequently, we failed to retrieve data to establish the one or the five years survival rates of the patients.Indeed, after hospital discharge, most of the patients return in rural area and continue with traditional medication, with seems to be affordable for them.
Therefore, the first important finding in our study is that the distribution of esophageal cancer among our population is similar to other studies in Sub-Saharan Africa.Indeed, our findings showed that the esophageal cancer constitutes 8.6% of digestive cancer and that it affects most frequently male population.The same is in Rwanda, the neighboring country with almost the same culture and ethnical groups, where the esophageal cancer occupies 9.4% of digestive cancers [9].Furthermore, a patchy study over a two-year period (1988)(1989) about digestive cancers in Bujumbura showed that the esophageal cancer constitutes the 4 th digestive cancer after the gastric, the liver and the colon cancer [10].However, authors of that study failed to make an epidemiological analysis because of a small number of esophageal cancer cases (only 8 cases) [10].Speaking of the situation prevailing in the Sub-Saharan Africa, esophageal cancer affects mostly males in Senegal (Dakar) with an average age of 49years [11].In Mali, the authors found a average age of 59 years [4].Similarly with our study, a number of African authors found an annual frequency of esophageal cancer inferior to 5cases per year [6] [12] [13].In general, studies about esophageal cancer in the Sub-Saharan African region seem to be patchy with small samples and concerned mainly in-hospital population.The lack of modern diagnostic tool, the small number of specialized centers and poverty constitute the main challenge in our region and could be a source of underestimation of the cancer.
The second important finding is that alcohol and tobacco abuse, as major risk factors, were implicated in 50% of cases in our study.Thus, that finding constitutes a great argument for the health authority in our country to regulate alcohol and tobacco consumption among population, particularly young people, in order to limit their unhealthy consequences.Also, it could be used as evidence in motivating a decree about alcohol and tobacco consumption in our country like it is done in some western countries.It seems to be a big challenge because people in Burundi have traditionally subscribed to the belief that alcohol constitutes a social link and its abuse becomes common, although it is one of the documented risk factors [1] [2].
The third important finding in our study is that the carcinoma was the most frequent type of esophageal cancer.It is a very aggressive histological type with a poor prognosis as well as in developed countries [14] [15].Also, our study population consulted late.Consequently, the prognosis was poor.The same situation is prevailing in a number of the Sub-Saharan African studies [4]- [6] [11].Mass education about early detection and prevention of cancer seems to be crucial in our country.

Conclusion
The present study showed evidence that the esophageal cancer in our country had the same characteristics and distribution like elsewhere in developing countries.The most frequent histopathological type was the squamous cell carcinoma.The diagnosis was delayed and the prognosis was poor.Efforts had to be done for prevention of risk factors and early detection of the disease.

Table 1 .
Epidemiological and clinical aspects of esophageal cancer in Bujumbura.

Table 2 .
Macroscopical and histopathological aspects of esophageal cancer in Bujumbura.