# International Extranodal Lymphoma Study Group

Source: https://onco.cc/companies/ielsg/  
OnCo record `ielsg` (Company). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

A Swiss-based international group that runs the trials defining treatment of rare extranodal lymphomas, including primary CNS lymphoma and gastric MALT lymphoma.

## Summary

Founded in 1997 and coordinated from the Oncology Institute of Southern Switzerland in Bellinzona, IELSG focuses on lymphomas arising outside lymph nodes, which no single country can study alone. IELSG32 established the MATRix regimen and consolidation strategies in primary CNS lymphoma, IELSG37 tested omission of mediastinal radiotherapy after PET-negative response in primary mediastinal B-cell lymphoma, and its gastric MALT lymphoma studies defined antibiotic and chlorambucil-rituximab therapy. It collaborates with LYSA, HOVON, the Nordic Lymphoma Group and Australian groups.

## Fields

- Kind: Company
- Last checked: 2026-09-09
- Also known as: IELSG
- Tags: cooperative-group
- HQ: Bellinzona
- Type: cooperative-group
- Website: https://www.ielsg.org

## Notes

- Primary CNS lymphoma (IELSG32, IELSG43)
- Primary mediastinal B-cell lymphoma (IELSG37)
- MALT lymphoma
- Rare extranodal lymphoma registries

## Sources

- IELSG: https://www.ielsg.org

## Connected records

- cancers: [Diffuse large B-cell lymphoma](https://onco.cc/cancers/dlbcl/)
- fronts: [Chemotherapy](https://onco.cc/fronts/chemotherapy/), [Radiation Therapy](https://onco.cc/fronts/radiation/)
- technologies: [FDG PET](https://onco.cc/technologies/fdg-pet/), [IMRT / IGRT (modern external beam)](https://onco.cc/technologies/imrt-igrt/), [Monoclonal antibodies](https://onco.cc/technologies/monoclonal-antibody/)
- companies: [HOVON](https://onco.cc/companies/hovon/), [LYSA (The Lymphoma Study Association)](https://onco.cc/companies/lysa/), [Nordic Lymphoma Group](https://onco.cc/companies/nordic-lymphoma-group/)
- people: [Andrés J. M. Ferreri](https://onco.cc/people/andres-ferreri/), [Franco Cavalli](https://onco.cc/people/franco-cavalli/)
- institutions: [Oncology Institute of Southern Switzerland (IOSI)](https://onco.cc/institutions/iosi-bellinzona/)
- trials: [IELSG32](https://onco.cc/trials/ielsg32/), [MATRix/IELSG43](https://onco.cc/trials/ielsg43/)

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JSON: https://onco.cc/api/v1/entities/ielsg.json