Rectal predominance and annular wall thickening: Abdominal computed tomography and clinical characteristics of colorectal cancer in a resource-limited setting.

BACKGROUND

Colorectal cancer (CRC) is the second-leading cause of cancer deaths worldwide, and its incidence is rising in developing countries. In resource-limited settings, abdominal CT scans are commonly used to detect and stage CRC before treatment. This study examined CT scan results and associated factors in patients suspected of having CRC at Muhimbili National Hospital between August 2019 and February 2020.

METHODOLOGY: This was a cross-sectional, hospital-based study of 60 patients with suspected CRC who were referred to our centre for abdominal CT. Clinical characteristics, abdominal CT findings, and histology results were recorded in a structured questionnaire. Categorical and numerical data were analyzed using frequency distribution tables, and the Chi-square (X2) test was used to assess the association between the independent and dependent variables. Multivariate logistic regression was performed to evaluate independent associations after adjusting for age and sex.

RESULTS

Most participants were over 40 years old (more females than males, 1.4:1). An unhealthy diet was common (71.7%). Main symptoms: constipation (61.7%) and hematochezia (58.3%). Among 60 suspected patients, colorectal tumours were confirmed in 56.7%, mostly rectal (26.7%), often with annular thickening (46.7%) and heterogeneous enhancement (43.3%). Abdominal CT showed good performance (sensitivity 88.9%, specificity 91.7%, accuracy 90.0%). Significant associations were found with lower education (p = 0.04), alcohol use (p = 0.02), and hematochezia (p = 0.03). These associations should be considered exploratory, given the small sample size and multiple comparisons performed.

CONCLUSION

CRC is present in the majority of patients with suspected cases who follow an unhealthy diet, occurring most commonly in the rectum and presenting as annular wall thickening on abdominal CT. This association is also linked to educational attainment and alcohol consumption.