Dietary risk factors for colorectal cancer in Uganda: a case-control study.

INTRODUCTION: Low-income countries in East Africa have a lower incidence of colorectal cancer (CRC) than high-income countries; however, the incidence has steadily increased in the last few decades. In Uganda, the extent to which genetic and environmental factors, particularly dietary factors, contribute to the aetiology of CRC is unclear. Therefore, the objective of our study was to determine the relationship between dietary factors and CRC in Uganda. METHODS: We conducted a case-control study and recruited 128 cases and 256 controls, matched for age (± 5 years) and sex. Data regarding the frequency of consumption of the dietary factors were obtained from all the participants using an interview-based questionnaire. The potential dietary risk factors and protective factors evaluated included the type and frequency of meat consumed and the type and frequency of high-fibre foods consumed. The frequency was either 4 or more times/week, 2-3 times/week, once/week or never. Conditional logistic regression analyses were used to determine the odds ratios associated with the different risk and protective factors. RESULTS: The median age (IQR) for the case participants was 55.5 (43-67.5) years, and that of the control participants was 54 (42-65) years. The male-to-female ratio was 1:1 for all the participants. Factors significantly associated with CRC cases included:- the consumption of boiled beef 2-3 times/week (aOR:3.24; 95% CI: 1.08-9.69; p < 0.035). Consumption of high-fibre foods, including:- millet for ≥ 4 times/week (aOR: 0.23; 95% CI: 0.09-0.62; p = 0.003)), spinach for ≥ 4 times/week (aOR:0.32; 95% CI: 0.11-0.97; p = 0.043), and potatoes 2-3 times/week (aOR: 0.30; 95% CI: 0.09-0.97; p = 0.044), were protective against CRC. Boiled cassava showed a tendency to reduce the likelihood of CRC when consumed ≥ 4 times/week (aOR:0.38; 95% CI: 0.12-1.18) however this did not reach statistical significance (p = 0.093). CONCLUSIONS: The consumption of boiled beef increases the risk of CRC, while the intake of high-fibre foods may reduce the risk of CRC among Ugandans. We recommend nutritional educational programmes to increase public awareness regarding the protective role of a high-fibre diet and to limit the intake of cooked meat in our Ugandan population.

Colorectal adenocarcinoma in Uganda: are right-sided and left-sided colon cancers two distinct disease entities?

INTRODUCTION: In Western countries, right-sided colon cancers (RSCC) present at an older age and advanced stage. Researchers believe that there is a difference between left-sided colon cancer (LSCC) and RSCC. In Uganda, however, it is unknown whether differences exist in the pathological profile between RSCC and LSCC. The aim of this study was to determine the differences in clinicopathological characteristics between RSCC and LSCC in Ugandan patients. METHODOLOGY: A cross-sectional study was conducted in which colorectal adenocarcinoma formalin-fixed paraffin-embedded tissue (FFPE) blocks were obtained from 2008 to 2021. Colorectal specimens were obtained from prospectively recruited patients. In the retrospective study arm, FFPE blocks and data were obtained from the archives of pathology laboratory repositories. Parameters studied included age, sex, location of the tumour, grade, stage, lymphovascular (LVI) status, and histopathological subtype between LSCC and RSCC. RESULTS: Patients with RSCC were not older than those with LSCC (mean age, 56.3 years vs 53.5 years; p = 0.170). There was no difference in the stage between RSCC and LSCC. Poorly differentiated tumours were more commonly found in RSCC than in LSCC (18.7% vs 10.1%; p = 0.038). Moderately and poorly differentiated colonic tumours were more common with RSCC (89.3%) than with LSCC (75.1%) (p = 0.007). Younger patients had more poorly differentiated tumours than older patients (19.6% versus 8.6%; p = 0.002). LVI was more common with RSCC than with LSCC (96.8% vs 85.3%; p = 0.014). Mucinous adenocarcinoma (MAC) was more common with RSCC (15.8%) compared with LSCC (8.5%) (p = 0.056) although statistical significance was borderline. CONCLUSIONS: Clinicopathological features of RSCCs tend to be different from those of LSCCs. RSCCs tend to be associated with MAC, a higher grade and LVI status compared to LSCC. LSCC and RSCC present predominantly with an advanced stage; therefore, national screening programmes for the early detection of CRC are necessary to reduce mortality in our Ugandan population.

Risk Factors for Colorectal Adenocarcinoma in an Indigenous Population in East Africa.

Introduction: The incidence of colorectal cancer (CRC) is increasing in East Africa. Changes in lifestyle and dietary changes, particularly alcohol consumption, smoking, and consumption of cooked meats with a reduction in fibre in the diet may be responsible. The objective of our study was to determine the risk factors responsible for CRC in Uganda. Methods: We recruited 129 participants with histologically proven colorectal adenocarcinoma and 258 control participants from four specialized hospitals in central Uganda from 2019 to 2021. Controls were block matched for age (±5 years) and sex of the case participants. The risk factor variables included; area of residence, tribe, body mass index (BMI), smoking, alcohol consumption and family history of gastrointestinal cancer. We used conditional or ordinal logistic regression to obtain crude and adjusted odds ratios for risk factors associated with CRC. Results: In bivariate analysis, case participants were more likely to be associated with urban residence (cOR:62.11; p<0.001); family history of GI cancer (cOR: 14.34; p=0.001); past smokers (cOR: 2.10; p=0.080); past alcohol drinkers (cOR: 2.35; p=0.012); current alcohol drinkers (cOR: 3.55; p<0.001); high BMI 25-29.9 kg/m2 (cOR: 2.49; p<0.001); and high BMI ≥30kg/m2 (cOR: 2.37; p=0.012). In the multivariate analysis, urban residence (aOR: 82.79; p<0.001), family history of GI cancer (aOR: 61.09; p<0.001) and past smoking (aOR: 4.73; p=0.036) were independently associated with a higher risk of developing CRC. Conclusion: A family history of gastrointestinal cancer was a risk factor for CRC. While population-based CRC screening may not be feasible in low income-countries, targeted CRC screening for first-degree relatives with CRC should be considered in East Africa. Molecular genetic studies need to be carried out to determine the role of hereditary factors in our population. Prevention strategies should be adopted to avoid smoking in our population which was associated with an increased risk of CRC.

Prognostic Factors for Survival of Colorectal Adenocarcinoma Patients in Uganda.

BACKGROUND: In Uganda, similar to other countries in East Africa, the incidence of colorectal cancer (CRC) has been steadily increasing. This increase in incidence is accompanied by a poor prognosis. There is limited knowledge on factors responsible for the poor outcome of patients with CRC in Uganda. Cancer survival analysis is one way of determining some of these prognostic factors. The aim of this study was to determine prognostic factors associated with CRC survival in Ugandan patients. METHODS: This was a retroprospective cohort study involving patients with linked data in the Kampala cancer registry and medical records from hospitals in Uganda. Participants with a diagnosis of colorectal adenocarcinoma between 1st January 2008 and 31st December 2018 were included. Variables included patients' demographic data, grade, stage and location of CRC, data on whether a patient was operated on, type of operation, treatment modalities and date of diagnosis. Our outcome variable was time to death after diagnosis. We computed and compared survival using the Log rank test and used Cox proportional hazards regression to determine factors associated with survival. RESULTS: A total of 247 patients were included in the study with a mean (SD) age of 53.3 (15.7) years and a female: male ratio of 1.14:1. The proportions of patients surviving at 1, 2 and 3 years were 65.2% (95% CI: 58.8-70.9), 42.0% (95% CI:35.6-48.3) and 33.3% (95% CI:27.3-39.4) respectively. In multivariate analysis, factors associated with increased mortality included clinical stage II (aHR = 2.44, 95% CI: 1.10-5.41, p=0.028), stage III (aHR=2.65, 95% CI: 1.31-5.39, p=0.007) and stage IV (aHR=5.47, 95% CI: 2.40-12.48, p<0.001). Curative surgery alone (aHR=0.63, 95% CI: 0.39-1.01, p=0.057) and curative surgery with chemotherapy (aHR=0.53, 95% CI: 0.32-0.88, p=0.015) were associated with a better survival. CONCLUSION: The survival rate among CRC patients in Uganda is low. Advanced stage CRC accelerates mortality, while surgery alone or in combination with chemotherapy improves survival. Implementation of national screening programmes for early diagnosis of CRC and increasing surgery and oncology infrastructure is recommended to improve the CRC survival rate in the Ugandan population.