Nephroblastoma (Wilms' Tumor): Sex and Age Distribution and Correlation Rate with Ages, Sex, and Kidney Side in Sana’a City, Yemen

Abstract

Background: Wilms' tumor is a malignant tumor that contains metanephric blastema, stromal and epithelial derivatives. The characteristic is the presence of abortive tubules and glomeruli surrounded by the stroma of a spindle cell. The stroma may include striated muscle, cartilage, bone, adipose tissue, and fibrous tissue. Aims: The study aimed to describe the age, sex and histology distribution of Wilms’ tumor and its association with age groups, sex and the side affected by the kidneys. Subjects and methods: A retrospective observational study was performed on renal masses patients who were consequently diagnosed selectively by histopathological study in the National Center for Public Health Laboratories (NCPHL) at the Department of Pathology, and the Department of Pathology in Al-Thorah university hospital, Sana'a, Yemen, over a period of 18 years from January 1, 2004 to December 31, 2021. Data were collected from hospital records. The study variables were lesions histological types, benign, malignancy, non-neoplastic lesions, sex, grades and age. The whole data were analyzed by IBM SPSS Statistics 22.Ink. The outcomes for variables were given in the form of rates (%). Chi Square was used for categorical variables that measured association among categorical variables. P-values less than 0.05 were considered significant. Results: Wilms tumors counting 47/282 (16.7%) of total diagnostic malignant tumors. The female cases were 29/47 (61.7%) more than male cases 18/47 (38.3%) with M:F ratio equal to 1.0: 1.6. The mean age of the Wilms’ patients was 5.3 years with SD equal to 3.6 years and ages ranged from 9 months to 15 years. Most of the Wilms’ patients were in age group 1-5 years 31/47(66%) followed by 6-10 years (25.5%). Favorable histology (FVH) Wilms’ tumors with better prognosis counting 42/47 (89.4%) while unfavorable histology (UFVH) with poor prognosis only counting 5/47 (10.6%). There was no significant association between Wilms’ tumor and gender while there was a highly significant association of Wilms’ tumor with 1-5 years group (rate = 77.5%, OR=48.6, CI =19.8-119, p <0.001) and with 6-10 years group (rate= 80%, OR=26.6, CI=7.1 – 98.7, p <0.001). There was no significant association between Wilms’ tumors with kidney side in which roughly equal rates were present in both side. Conclusion: Wilms' tumors in Yemeni children appear at an early age and peak in the first 5 years of life with an increased incidence among females with predominantly FVH. The current study provided much needed information about the burden of Wilms' cancer in Yemen, to enable Yemen to better plan to address the burden. Further studies are necessary to determine the exact incidence and trend of Wilms' cancer and risk factors in Yemen.