Background: Urinary bladder cancer (UBC) is the ninth most common cancer in the world, and the third most common cancer among men in West Asian countries, including Arab countries. Despite the increasing prevalence of UBC in developing countries, many places, including Yemen, do not have representative studies showing the true impact of these tumors on the population.
Aims: Describe different types, age, sex distribution and associated different types with gradation, invasion muscles and schistosomiasis in the last ten years in a single Yemeni institute.
Materials and methods: An observational descriptive study was performed on UBC patients who were subsequently diagnosed selectively by histopathological study in the Department of Pathology at the National Center for Public Health Laboratories (NCPHL) Sana'a, Yemen, over a period of about 10 years from January 1, 2012 to October 31, 2021. The study variables were qualitative (cancer histological type, sex, grades and quantity (age). Types, grading and histological diagnoses were formed in line with the World Health Organization classification of bladder cancer.

Results: Most of the cases were in the age group 60-69 years (32%), followed by 70 years (22.3%), and 50-59 years (20%). The mean age ± SD of the total was 57.1 ± 13.4 years. Of the 520 UBCs, 71.5% were urothelial neoplasms (UNs), 24.4% were squamous neoplasms (SNs), 2.3% were glnadular neoplasms (GNs), 0.6% were neuroendocrine glnadular neoplasms (NENs) and 0.96% were mesenchymal glnadular neoplasms (MNs). There was a cytologically high grade with a significance rate (64.2%) with UNs while no significant association with the remaining types of UBCs. There was a significance rate of: schistosomiasis (43.8%) with SNs as OR= 19.5 (p < 0.001), and invasion of muscle fibers (66.4%) with SNs as OR= 3.3, UNs (37.1%) as OR= 11.2 (p < 0.001). Also there was a significance rate 2of GII grade (46.1%) with SNs as OR= 64.1 (p < 0.001) and GNs (33.3%) as OR= 3.8 (p = 0.02).
Conclusion: The current study recorded data congruence with those in the international literature and reports of neighboring countries, with some minor differences. This study documents a high incidence of urothelial neoplasms, with a male predominance and a peak incidence in the sixth decade of life. Imminent studies are needed to identify risk factors that increase cystitis in more detail and to study genetic susceptibility to inflammation and inflammatory markers before cancer is diagnosed.