Pattern of HER2 overexpression in urinary bladder carcinomas in Kano, Nigeria

Background: The worldwide distribution of bladder cancer varies, conforming to differences in environmental and genetic risk factors. HER2 neu is overexpressed in many human cancers, including urinary bladder carcinomas. The aim of this study is therefore to evaluate the pattern of HER2 positivity, and correlate HER2 positivity of urinary bladder carcinomas with age, gender of patients, histological subtypes, and tumor grades. Methods: This is a 2-year retrospective study from January 2015 to December 2016. Patients’ clinicopathological information was extracted from their case folders and pathology reports. The histological subtyping using the WHO 2016 classification and grading was done and then reviewed by authors. HER2 scoring was done using the recommendations of the American Society of Clinical Oncology/College of American Pathologists. Results: Sixty cases of bladder cancer were diagnosed during the study period. HER2/neu positivity (3+) was observed in 24 (40%) of all the cases. Statistically significant association was observed between HER2 neu protein overexpression and increasing tumor grade (p≤ 0.001). Conclusion: This study recorded HER2 overexpression in 40% of study subjects. There is a statistically significant association between HER2 overexpression and increasing tumor grade.