Esophageal cancer in north rift valley of Western Kenya.

BACKGROUND: Cancer of esophagus is the 9 th It is aggressive with poor prognosis especially in its late stage. Cancer of esophagus is geographically unevenly distributed with high incidence found within sharply demarcated geographic confines. Earlier reports from this country indicated relatively high proportion of cases in residents of Western and Central provinces with low incidence in the residents of the Rift Valley Province. This does not seem to be in agreement with our findings. Several aetiological factors have been associated with this type of cancer although their definitive mechanistic role is not clear. OBJECTIVE: The main aim of this study was to describe the incidence, clinical epidemiology and histology of esophageal cancer in the North Rift region of Western Kenya, which forms the patients catchment area of Moi Teaching and Referral Hospital, Eldoret. METHODS: This study involved a review of all available pathology reports beginning from January 1994 up to May 2001 from Moi Teaching and Referral Hospital. All reports of esophageal cancer were abstracted and analyzed according to gender, age and ethnical background. All cases were based on histological diagnosis. Statistical analysis was performed using the SPSS software package. RESULTS: Esophageal cancer in this area is the most common cancer in men, yet it is the third common cancer in women. A male to female ratio of 1.5 to 1 was observed. Our finding also contrast with an earlier reported study that indicated that Rift Valley is a low prevalence area for this type of cancer. The mean age of the patients with this cancer was 58.7 years. The ethnic group most afflicted were Nandis and Luhyas. They are the majority tribes in this area. Squamous cell carcinoma accounted for 90% of the cases. CONCLUSIONS: Cancer of the esophagus is the most common malignancy in males and the third common malignancy in females in the catchment area of Moi Teaching and Referral Hospital, Eldoret. There is need to carry out further work to establish the aetiologic factors behind this neoplasm. This study forms a preliminary basis of further investigation to be undertaken to identify genes that are mutated during the carcinogenic development of this cancer. This may lead to identification of molecular biomarkers to be used in future for the early detection of this neoplasm.

Esophageal Cancer, the Topmost Cancer at MTRH in the Rift Valley, Kenya, and Its Potential Risk Factors.

Esophageal cancer at Moi Teaching and Referral Hospital (MTRH) is the leading cancer in men with a poor prognosis. A case control study (n = 159) aimed at the histology type, gender, and risk indicators was carried out at MTRH. Mantel Haenszel chi-square and logistic regression were employed for analysis. Squamous-cell carcinoma was the common histological type occurring in the middle third portion of the oesophagus. The occurrence of the cancer in males was 1.4 times that of females. The mean age was 56.1 yrs. Low socioeconomic, smoking, snuff use, alcohol, tooth loss, cooking with charcoal and firewood, hot beverage, and use of mursik were independently associated with esophageal cancer (P < 0.05). Using logistic regression adjusted for various factors, alcohol consumption was associated with the increased risk of esophageal cancer. AHR was 0.45 and 95% CI: 0.205-0.985, P = 0.046. A societal component of low socioeconomic conditions, a lifestyle component with specific practices such as the consumption of mursik, chang'aa, busaa, snuff, smoking, hot tea, poor oral hygiene, and an environmental component with potential exposure to high levels of nitrosamines, passive smoking, and cooking with coal, could be involved. The increase in experts at MTRH capable of diagnosing could be responsible for the increase in reporting this neoplasm.

TP53 mutations, human papilloma virus DNA and inflammation markers in esophageal squamous cell carcinoma from the Rift Valley, a high-incidence area in Kenya.

BACKGROUND: Squamous Cell Carcinoma of Esophagus is one of the most common malignancies in both men and women in eastern and south-eastern Africa. In Kenya, clinical observations suggest that this cancer is frequent in the Rift Valley area. However, so far, there has been no report on the molecular characteristics of esophageal squamous cell carcinoma (ESCC) in this area. RESULTS: We have analyzed TP53 mutations, the presence of human papilloma virus (HPV) DNA and expression of inflammation markers Cyclooxygenase 2 (Cox-2) and Nitrotyrosine (NTyR) in 28 cases (13 males and 15 females) of archived ESCC tissues collected at the Moi Teaching and Referral Hospital in Eldoret, Kenya. Eleven mutations were detected in TP53 exons 5 to 8 (39%). All ESCC samples were negative for HPV 16, 18, 26, 31, 33, 35, 39, 45, 51, 52, 53, 56, 58, 59, 66, 68, 70, 73 and 82. Immunohistochemical analysis of Cox-2 and NTyR showed a low proportion of positive cases (17.4% and 39.1%, respectively). No association between the above markers and suspected risk factors (alcohol or tobacco use, hot tea drinking, use of charcoal for cooking) was found. CONCLUSION: Our findings suggest that mechanisms of esophageal carcinogenesis in eastern Africa might be different from other parts of the world. Low prevalence of TP53 mutation compared with other intermediate or high incidence areas of the world highlights this hypothesis. Our data did not support a possible ole of HPV in this series of cases. Further studies are needed to assess and compare the molecular patterns of ESCC from Kenya with those of high-incidence areas such as China or Central Asia.