Racial Differences in the Phenotype of Colorectal Cancer: A Prospective Comparison Between Nigeria and South Africa
Bibliographic record
Abstract
INTRODUCTION: There are significant differences in the phenotype of CRC by race in the U.S. A similar CRC phenotype-race relationship also appears to exist in South Africa (SA). However, there is a paucity of comparative data on the presentation and survival of CRC in sub-Saharan African by country of origin or race. This study compares clinicopathologic variables between CRC patients in Nigeria and SA. METHODS: From a prospective CRC database, consecutive patients diagnosed between September, 2013 and October, 2018 from the African Research Group for Oncology in South West Nigeria were compared to consecutive patients diagnosed from January, 2016 to October, 2018 from the Colorectal Cancer in South Africa database. Patients with histologically confirmed adenocarcinoma were included. Patients were excluded if they had in-situ disease or no histological diagnosis. Clinical outcomes were calculated from the date of presentation. National census categories were used to define self-reported race in SA. RESULTS: The mean age at presentation in Nigeria (n = 347) was 54.1 years (SD 15.5) compared to 56.8 (SD 13.7) in SA (n = 534). The median age among Black SA (BSA) patients was significantly lower than the median age among White SA (WSA) patients (55 vs. 63, p < 0.001). Right-sided colon cancer was more common in Nigerian (27.4%) and BSA (21.2%) patients compared to WSA patients (15.2%, p < 0.001). Nigerian (39.1%) and BSA (16.7%) patients were also more likely to present with mucinous histology than WSA patients (4.9%, p < 0.001). There was a significant difference in the stage-at-presentation between the cohorts, with a large burden of stage IV disease in the Nigerian cohort (52.6%). Adjusting for stage-at-presentation, there was a significant difference in the median overall survival between country and racial cohorts. CONCLUSION: There are significant differences in the phenotype of CRC between Nigeria and SA. Nigerian and BSA patients, appear to share characteristics that are different than those of WSA patients. Larger series with tissue banking and next-generation sequencing are needed to better delineate these observed differences.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".