Classification of Non-Hodgkin Lymphoma in Seven Geographic Regions Around the World: Review of 4539 Cases from the International Non-Hodgkin Lymphoma Classification Project
Bibliographic record
Abstract
Abstract INTRODUCTION The distribution of non-Hodgkin lymphoma (NHL) subtypes varies around the world, but a large and systematic comparative study has not been done. This study is first to evaluate the relative frequencies of NHL subtypes in seven regions of the world. METHODS Five expert hematopathologists classified 4848 consecutive cases of NHL from 25 countries in seven regions, including North America, Central/South America, Western Europe, Southeastern Europe, Southern Africa, the Middle East/North Africa, and the Far East, using the WHO classification. Data from the developed world (North America and Western Europe) was compared to the developing world (all other regions combined). RESULTS Among the 4848 cases reviewed, 4539 (93.6%) were confirmed to be NHL, whereas the other 309 (6.4%) had diagnoses other than NHL and were excluded from further analysis. A significantly higher male to female ratio was found in the developing regions (1.4:1) compared to the developed world (1:1; p<0.05). The median age at diagnosis was significantly lower for both low grade (LG) and high grade (HG) B-NHL in the developing regions (59 and 54 yrs, respectively) compared to the developed world (62 and 64 yrs, respectively). The developing regions had a significantly lower frequency of B-NHL (86.6%) and a higher frequency of T-NHL (13.4%) compared to the developed world (90.7% and 9.3%, respectively). Furthermore, the developing regions had significantly more cases of HG B-NHL (58.7%) compared to the developed world (43.9%). Among B-cell lymphomas, diffuse large B-cell lymphoma (42.5%) and Burkitt lymphoma (2.2%) were significantly more common in the developing regions, compared to the developed world (28.9% and 0.8%, respectively). Follicular lymphoma (15.3%), mantle cell lymphoma (3.8%), marginal zone lymphoma of mucosa-associated lymphoid tissue (5.2%), and lymphoplasmacytic lymphoma (0.3%) were significantly less common in the developing regions, compared to the developed world (25.5%, 7.8%, 8.8%, and 1.4%, respectively). Among T-cell lymphomas, precursor T-lymphoblastic lymphoma (2.9%) and nasal NK/T-cell lymphoma (2.2%) were more common in the developing regions, compared to the developed world (1.3% and 0.3%, respectively). CONCLUSION Our study is the first to systematically compare the relative frequencies of NHL subtypes in different regions around the world, and provides new evidence of significant geographic differences. Our findings suggest that differences in etiologic and/or host risk factors are likely responsible, and more detailed epidemiologic studies are needed to better understand these differences. Disclosures Armitage: Celgene: Consultancy; Ziopharm: Consultancy; Tesaro Bio, Inc: Membership on an entity's Board of Directors or advisory committees; GlaxoSmithKline: Consultancy, Membership on an entity's Board of Directors or advisory committees; Conatus: Consultancy, Membership on an entity's Board of Directors or advisory committees; Roche: Consultancy; Spectrum: Consultancy.
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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 | 0.003 | 0.005 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.006 | 0.006 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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".