The distribution of esophageal cancer patients enrolled in care at the Uganda Cancer Institute by sub-regions, districts and ethnicity

Background There is limited published data regarding the distribution of esophageal cancer patients by sub-regions, districts and ethnicity in Uganda. Objectives To study the distribution by sub-regions, districts, ethnicity and sub-regions post-care outcomes of esophageal cancer patients in care over ten years at the Uganda Cancer Institute. Methods Patients' charts with confirmed diagnoses of esophageal cancer for 2009–2019 were identified. Case information, which included demographics, clinical presentation, distribution by sub-regions, districts, ethnicity and sub-regions post-care outcomes, were retrospectively abstracted. Results Central 671(34.15%), Southwestern 308(15.67%), Elgon 176(8.95%) and East central 163(8.29%) sub-regions had most patients. Mostly from administrative districts of Wakiso 167(8.50%), Mbarara 51(2.59%), Tororo 53(2.70%), Busia 33(1.68). Baganda, Banyakole, Bagisu and Basoga ethnic groups predominate. Patients from neighbouring countries were mainly from Rwanda 56(2.85%), South Sudan 24(1.22%), then Kenya 21(1.07%), and Rwandese, Dinka and Luo by ethnicity, respectively. Central and Southwestern sub-regions had the most post-care outcomes of the patients regarding living, death, and loss to follow-up. Conclusion Patients are commonly from the administrative districts of Central, Southwestern, Elgon and East Central sub-regions and neighbouring countries of Rwanda, South Sudan and Kenya. Baganda, Banyakole, Bagisu and Basoga are the main ethnic groups. Central and Southwestern sub-regions are with most post-care outcomes.


Introduction
Esophageal cancer is the seventh most common cancer and the sixth leading cause of cancer death worldwide 1 .More than 80% of cases and deaths from esophageal cancer occur in developing countries [2][3][4] .The incidence of esophageal cancer varies globally, with a higher incidence in areas such as Eastern Asia, South Central Asia, South Africa, Eastern Africa, and Northern Europe [1][2][3][4] .In Uganda, one of the countries comprising the East African sub-region, the incidence and trend of esophageal cancer is increasing [5][6][7][8][9] .In Uganda, esophageal cancer ranks sixth and is the third common cause of cancer-related death, accounting for 8.7% 9 .The male-to-female risk ratio is about 2:1 6,9,10 .Despite the rising esophageal cancer incidence in Uganda, there is limited data about the clinical characteristics, distribution by sub-regions, districts, ethnicity and sub-regions post-care outcomes for this tumor type.This study aimed to characterize esophageal cancer patients seeking care over ten years in terms of distribution by sub-regions, districts, ethnic groups and sub-regions post-care outcomes.Therefore, the baseline data obtained from this study will be the first important step for developing resources, enhancing esophageal cancer care in our population, and performing additional research.

Methods
This was a retrospective chart review study of confirmed esophageal cancer patients referred to the Uganda Can-cer Institute, a national referral cancer center, between 2009 and 2019 for care.Data collected on each patient's chart included age, sex, occupation, Body Mass Index (BMI), Eastern Cooperative Oncology Group (ECOG) performance status, main referral complaint, diagnostic method, ethnicity, their districts, sub-region locations, and sub-regions post-care outcomes.Data were collected and stored using the RedCAP database.This study was approved by the Ugandan National Council for Science and Technology and the Uganda Cancer Institute.

Statistical analysis
Mean values and standard deviations were calculated for continuous variables.Counts of categorical variables described the distributions of demographic, clinical characteristics variables and esophageal cancer in each sub-region, district, or from a neighbouring country.The relationship between patient's sub-regions by districts, ethnicity and post-care outcomes was determined by cross-tabulation.

Discussion
One thousand nine hundred and sixty-five esophageal cancer cases were reviewed, and males were predominant with a male: female ratio of approximately 2:1.The male predominance demonstrated in this study is like other studies performed in Africa, particularly in the East African region [9][10][11][12][13] .The male predominance could be explained by the fact that most of the known risk factors for esophageal cancer are related to behavior-smoking and excessive alcohol consumption, of which men are known to be worse consumers than women, as has been shown by studies in Africa and China [14][15][16][17][18][19][20] .
Our study highlights esophageal cancer occurring in older age (>50 years), similar to earlier studies in the north rift valley of western Kenya, Tanzania, Mozambique, South Africa, Ethiopia, and Iran 11,[21][22][23][24][25] .These findings can be explained by the fact that the chance of getting oesophageal cancer increases with age.However, the age may vary from country to country since it highly depends on the underlying population structure.
Most of the esophageal cancer patients seeking care were in agriculture, which is unsurprising as Uganda is an agricultural country with 72.1% of the working population employed in this sector.In our study, dysphagia was the most symptom of esophageal cancer at the time of diagnosis.All the esophageal cancer was diagnosed through upper gastrointestinal endoscopy plus biopsy for histopathology, keeping with a comprehensive series of published reports in East Africa, South Central Asia and East Asia 13,[25][26][27] .
Our data demonstrate more than 60% of the patients were underweight at presentation.This result is explained by the fact that most of our patients (80.30%) had progressive difficulty swallowing, thus losing weight due to reduced intake and low body mass index before presenting for care.This finding is similar to the Zambian study that found 62.7% of esophageal cancer patients underweight 26 .
In our study, most patients, 92.26%, had the Eastern Cooperative Oncology Group score (ECOG) performance status between 1-3.This finding contrasts with other studies from Korea, China, and France [28][29][30][31] , where most patients had ECOG between 0-1.The high ECOG scores in our study could have probably indicated most of our patients being very sick, with the burden of preexisting disease hence a poor ECOG performance status.
Distribution, our study demonstrated most of the patients were from administrative districts of most sub-regions.This result is by the Tanzanian study for patients treated for esophageal cancer, which found higher incidence rates in administrative regions and the United States of America, where most patients were from metropolitan and urban areas 32,33 34 .This report concurs with our findings explaining the burden of esophageal cancer in the Elgon sub-region districts despite not having cancer treatment hospitals.Most esophageal cancer patients accessing care from the neighbouring countries were from Rwanda, South Sudan, and Kenya.
Sub-regions post-care outcomes; our study highlights the Central and Southwestern sub-regions with the most post-care results of the patients regarding living, dead, and lost to follow-up.These post-care results could probably partly be explained by the many patients who came in for care from these sub-regions, among other contributing factors.

Limitations
This study has some limitations.Only a tertiary national referral hospital was involved.Thus, cases referred from regional and district hospitals that didn't make it into care may have been missed; therefore, case ascertainment may be incomplete.We cannot exclude diagnostic bias based on interest, expertise, and access to diagnostic facilities.

Conclusion
This study revealed higher proportions of esophageal cancer patients seeking care are mainly from administrative districts of Central, Southwest, Elgon, Eastern African Health Sciences, Vol 24 Issue 1, March, 2024 Central and Western sub-regions.Baganda, Banyakole, Bagisu, Basoga and Batooro are the main ethnic groups.
Central and Southwestern sub-regions are with most postcare outcomes of the patients regarding living, death, and loss to follow-up.The neighbouring countries included patients from Rwanda, South Sudan, Kenya, then Congo.This study demonstrates the need for prioritizing esophageal cancer care to involve non-administrative rural areas of Uganda and nutritional assessment to help improve patients' nutritional status as they enrol in care, as most patients have low body mass index.

Figure 1 :
Figure 1: Map of Uganda showing sub-regions and corresponding districts.

Table 1 :
Demographic and clinical characteristics of esophageal cancer patients

Table 3 .
Distribution in Central, Southwestern, Elgon, East Central and Western districts

Table 5 :
Ethnic groups in care that had the most esophageal cancer in each sub-region

Table 6 :
Post-care outcomes of patients from each sub-region and neighbouring countries LFU= Lost to follow-up, South.W = Southwestern, East.C = East Central, West.N = West Nile.
. Central had the most patients, 34.15% among the sub-regions; the high numbers from central might be related to more accessibility to care as our study hospital (Uganda Cancer Institute) is located in the central region urban area of Uganda.It is worth noting that some sub-regions with high numbers of patients were significantly farther from the central sub-region and the Uganda Cancer Institute in our study.For example, Southwestern (15.67%),Elgon (8.95%) and East Central 8.29% sub-regions.An earlier study looking at risk factors for esophageal cancer among adults aged 40 years and above in eastern Uganda, Elgon sub-region, reported esophageal cancer as one of the biggest health problems and the leading cause of cancer-related mortality in the region