Retrospective analysis of histological types and laterality of breast carcinoma in a tertiary hospital in Southwest Nigeria

Abstract

Background: Breast carcinoma is the most common cancer among women worldwide and is a leading cause of death among women. It has various histological types, which differ in their clinical and pathological features. In Nigeria, it accounts for over 25% of all cancer cases. The evolving nature of breast cancer calls for a continuous study of the histological types, distribution patterns, and unique characteristics as it may reveal new insights and variations. Therefore, this study aimed to determine the histological types, age distribution, and laterality of breast carcinoma cases at the UNIOSUN Teaching Hospital (UTH) Osogbo.
Methods: This study was a retrospective analysis of all cases of breast carcinoma diagnosed histologically at the UTH Osogbo over 10 years. Information on patients age, laterality, and histological type of breast carcinoma was obtained from the records of the Department of Pathology. The histological types were classified according to the World Health Organization (WHO) classification system and data was analyzed using descriptive statistics.
Results: A total of 519 cases of breast carcinoma were diagnosed histologically. The mean age of the patients was 50.1 years (SD=12.4), with a range of 12-90 years. The highest number of cases (32%) were in the age group of 41-50 years, followed by 29.5% in the age group of 31-40 years. Invasive ductal carcinoma (NOS) was the most common histological type, accounting for 93.6% of cases. Other types were metaplastic carcinoma (2.7%), invasive mucinous carcinoma (1.3%), lobular carcinoma (1%), and medullary carcinoma (0.4%). Regarding laterality, 53% of the cases were in the left breast, 44% in the right breast, and 3% were bilateral.
Conclusion: Invasive ductal carcinoma (NOS) was the most common histological type. Breast cancer was common among those aged 41-50 years and in the left breast. The results of this study could be useful for the development of breast cancer screening programs and treatment strategies in Nigeria.