Pattern of Lower Gastrointestinal Tract Malignancies in National Hospital Abuja: A 5-Year Retrospective Study

Aims: To determine the pattern, frequency, socio-demographic characteristics, histological types, stage at presentation, risk factors and treatment modalities of lower gastrointestinal tract malignancies managed at National Hospital Abuja over a five-year period and to compare the findings with similar studies locally and internationally. Study Design: Retrospective descriptive hospital-based study. Place and Duration of Study: The study was conducted at the Department of Radiotherapy and Oncology, National Hospital Abuja-Nigeria, covering a five-year period from August 2014 to August 2019. Methodology: Data were extracted retrospectively from patients’ case notes using a structured data extraction sheet. Eligible cases included all patients with histologically confirmed lower gastrointestinal tract malignancies involving the small intestine, colon, rectum and anus within the study period. Variables collected included socio-demographic data, clinical presentation, histological diagnosis, stage at presentation, risk factors and treatment modalities. Data was analyzed using the Statistical Package for Social Sciences (SPSS) version 20. Results were presented using descriptive statistics. Results: A total of 207 cases of lower gastrointestinal tract malignancies were recorded. Males accounted for 126 cases (61 percent) and females 81 cases (39 percent), giving a male to female ratio of 1.6:1. The mean age was 52.02 years, with the highest frequency occurring in the 51 to 60-year age group. Colorectal cancer constituted the majority of cases and adenocarcinoma was the predominant histological type which accounted for 187 cases (90 percent). Squamous cell carcinoma accounted for 7 cases (3.4 percent), while carcinoid tumours, lymphomas, gastrointestinal stromal tumours, malignant melanoma, small cell carcinoma and cloacogenic carcinoma together constituted less than 7 percent. Most patients presented with advanced diseases. Surgery was performed in 55 percent of patients, chemotherapy was administered in 90.3 percent either as neoadjuvant, adjuvant or palliative treatment. Chemoradiation was used in 33.8 percent of cases and radiotherapy alone was mainly used for palliation in 8.2 percent of cases. On multivariable-adjusted exact logistic regression analysis, HIV-related immunosuppression was the only risk factor independently associated with anal cancer compared with other lower gastrointestinal tract malignancies (p < 0.001). Treatment was largely multimodal, with chemotherapy used in over 90% of cases. Conclusion: Lower gastrointestinal tract malignancies, particularly colorectal cancers are common in Abuja. Strengthening the capacity to detect lower GIT cancers early, enhancing screening programs and public awareness is essential to improving outcomes. It is expected that future researchers will look at patterns of lower GIT cancers in the other regions within the country to collaborate our findings.