# Lung neuroendocrine tumours (typical and atypical carcinoid)

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

## TL;DR

Lung neuroendocrine tumours, called typical and atypical carcinoids, are slow-growing tumours of the airways that are usually cured by surgery. When they spread, everolimus is the one drug tested in a randomised trial for this site, cabozantinib was approved in 2025, and somatostatin analogues and lutetium radioligand therapy are borrowed from gut tumours.

## Summary

Lung neuroendocrine tumours are graded differently from their gut counterparts: the WHO lung classification separates typical carcinoid (fewer than two mitoses per two square millimetres and no necrosis) from atypical carcinoid (two to ten mitoses or foci of necrosis), with Ki-67 used to support the count rather than define it, and places both alongside small-cell and large-cell neuroendocrine carcinoma in a single neuroendocrine group. Most typical carcinoids sit centrally in a main or lobar bronchus and present with cough, wheeze, haemoptysis or recurrent pneumonia behind an obstructed airway; peripheral tumours are found incidentally. A few produce ectopic ACTH and Cushing's syndrome, carcinoid syndrome is uncommon without liver metastases, and diffuse idiopathic pulmonary neuroendocrine cell hyperplasia is a rare precursor that seeds multiple tumourlets. About a twentieth arise in patients with MEN1.

Surgery is the treatment for localised disease and usually the cure: lobectomy or a parenchyma-sparing sleeve resection with systematic nodal dissection, with endobronchial resection reserved for patients who cannot tolerate an operation. Adjuvant therapy has no proven benefit and follow-up is prolonged because atypical carcinoids can recur years later. For advanced disease the evidence is thin. RADIANT-4 (Lancet 2016) is the only randomised trial to include lung tumours in numbers: 302 patients with non-functional lung or gastrointestinal neuroendocrine tumours were randomised to everolimus or placebo and progression-free survival lengthened from 3.9 to 11.0 months, and the FDA approved everolimus for lung neuroendocrine tumours in 2016. The phase 2 LUNA trial (2017) tested pasireotide, everolimus and the combination in lung and thymic tumours and found each active, without a randomised comparison against placebo.

The rest of the sequence is borrowed. Somatostatin analogues are used for somatostatin receptor-positive tumours on the strength of gut trials and the small SPINET study of lanreotide, and lutetium-177 dotatate is given off-label to receptor-positive lung tumours on series data, since NETTER-1 and NETTER-2 enrolled only gastroenteropancreatic disease. CABINET (New England Journal of Medicine 2024) included lung and thymic tumours in its extra-pancreatic cohort, where cabozantinib lengthened progression-free survival from 3.9 to 8.4 months, and a subgroup analysis presented in 2025 showed a large reduction in progression risk in the lung and thymic tumours; cabozantinib's 2025 approval covers them. Temozolomide-based chemotherapy is used for atypical carcinoids that need shrinkage, and platinum-etoposide is reserved for tumours behaving like carcinoma.

## Fields

- Kind: Cancer
- Last checked: 2026-09-17
- Also known as: Bronchial carcinoid; Pulmonary carcinoid; Typical carcinoid; Atypical carcinoid; Lung NET; Bronchopulmonary neuroendocrine tumour
- Tags: subtype-page; endocrine; lung
- Group: lung
- Burden: A small minority of lung cancers, occurring in younger patients and non-smokers more often than other lung cancers; typical carcinoids are usually cured by surgery, atypical carcinoids recur more often.
- Subtypes: Typical carcinoid of the central bronchus (low mitotic count, no necrosis); Atypical carcinoid (two to ten mitoses or necrosis, higher recurrence); Peripheral lung neuroendocrine tumour (incidental, sometimes multiple); Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) with tumourlets; Lung carcinoid with ectopic ACTH and Cushing's syndrome; MEN1-associated lung neuroendocrine tumour; Thymic neuroendocrine tumour (grouped with lung in trials)
- Biomarkers: Mitotic count and necrosis (WHO typical versus atypical); Ki-67 index (supportive, not definitional in the lung); Somatostatin receptor PET (staging and somatostatin analogue or radioligand eligibility); Chromogranin A (monitoring); ACTH and cortisol where Cushing's syndrome is suspected; Germline MEN1 in young or multiple tumours

## Sections of this record

The page is a hub with ten sections in reading order; large sections have their own page. The same plan as JSON: https://onco.cc/api/v1/cancers/lung-net/sections.json

- Overview (on the hub): The TL;DR, the family this cancer belongs to, the organ, who gets it and what the state of the art is. https://onco.cc/cancers/lung-net/#overview [3 state-of-the-art points]
- Types and stages (on the hub): Anatomy, the subtypes and how they differ, how it is staged, and where advanced disease spreads. https://onco.cc/cancers/lung-net/#what-it-is [7 subtypes]
- Symptoms and diagnosis (on the hub): How this cancer shows itself, how the diagnosis is confirmed, and the biomarkers clinicians test for. https://onco.cc/cancers/lung-net/#finding-it [6 biomarkers]
- Treatment (on the hub): The standard of care by setting, the medicines, surgery and radiotherapy named in it, and the regimens behind them. https://onco.cc/cancers/lung-net/#treating-it [5 settings, 2 decisions with options]
- Trials and papers (on the hub): Trials recruiting now, the landmark trials, the trials held by this cancer's subtypes, the key papers and what they mean, the latest literature, and the milestones year by year. https://onco.cc/cancers/lung-net/#evidence [6 trials, 3 key papers, 6 milestones]
- Biology and targets (on the hub): The molecular landscape: the targets and how often each appears, the pathways, the mechanics stages and the preclinical models. https://onco.cc/cancers/lung-net/#science [7 targets]
- Countries and centres (own page): Cases by country, the UK and NHS pathway and other country lenses, the expert centres with trials on record, and the centres named on this cancer's subtypes. https://onco.cc/cancers/lung-net/where-you-are/
- Decisions and support (on the hub): The decisions you may face, the aids that walk through them, the warnings on record, the first sixty days and the questions to ask. https://onco.cc/cancers/lung-net/#living-with-it [20 questions, 6 red cards]
- Pipeline and open problems (own page): Everything in development, the medicines held by this cancer's subtypes, the open problems and what is being done about them, the roadmaps, and what changed on this record. https://onco.cc/cancers/lung-net/coming/ [7 medicines, 4 trials, 3 open problems]
- Data (own page): Every connected record, the notes, the JSON, Markdown and RDF twins, and where the record came from and when it was checked. https://onco.cc/cancers/lung-net/data/ [49 connected records, 1 note]

## Standard of care

- Diagnosis and staging: Bronchoscopy with biopsy for central tumours, CT of the chest and abdomen, somatostatin receptor PET, and pathology graded by mitotic count and necrosis. ([Bronchoscopy (EBUS, robotic navigation)](https://onco.cc/terms/bronchoscopy/), [CT (computed tomography)](https://onco.cc/technologies/ct/), [Somatostatin receptor PET (68Ga/64Cu-DOTATATE)](https://onco.cc/technologies/sstr-pet/), [Gallium-68 DOTATATE (and Cu-64 DOTATATE)](https://onco.cc/drugs/ga68-dotatate/), [Neuroendocrine tumour grade (Ki-67) and WHO classification](https://onco.cc/terms/net-grade-ki67/))
- Localised disease: Lobectomy or sleeve resection with systematic nodal dissection; endobronchial resection for patients unfit for surgery; no adjuvant therapy. ([Lobectomy](https://onco.cc/terms/lobectomy/), [Robotic & minimally invasive surgery](https://onco.cc/technologies/robotic-surgery/))
- Advanced, somatostatin receptor-positive, slow tempo: Octreotide or lanreotide, by extrapolation from gut trials and the SPINET study. ([Somatostatin analogues (octreotide, lanreotide)](https://onco.cc/drugs/octreotide-lanreotide/), [CLARINET](https://onco.cc/trials/clarinet/))
- Advanced, progressive: Everolimus (RADIANT-4); cabozantinib (CABINET); lutetium-177 dotatate off-label for receptor-positive tumours; temozolomide-based chemotherapy for atypical carcinoids needing shrinkage. ([Everolimus](https://onco.cc/drugs/everolimus/), [RADIANT-3 and RADIANT-4](https://onco.cc/trials/radiant-3-4/), [Cabozantinib](https://onco.cc/drugs/cabozantinib/), [CABINET (Alliance A021602)](https://onco.cc/trials/cabinet/), [Lutetium-177 dotatate](https://onco.cc/drugs/lutathera/), [Peptide receptor radionuclide therapy (PRRT)](https://onco.cc/technologies/prrt/), [Capecitabine + temozolomide (CAPTEM)](https://onco.cc/drugs/capecitabine-temozolomide/))
- Hormone syndromes: Somatostatin analogues for carcinoid syndrome; steroidogenesis inhibitors or resection for ectopic ACTH. ([Somatostatin analogues (octreotide, lanreotide)](https://onco.cc/drugs/octreotide-lanreotide/), [Carcinoid syndrome and carcinoid heart disease](https://onco.cc/terms/carcinoid-syndrome/))

## State of the art

- Surgery cures most typical carcinoids, and parenchyma-sparing sleeve resection preserves lung function.
- Everolimus is the only drug with randomised evidence specific to lung neuroendocrine tumours, and cabozantinib joined it in 2025 through the CABINET extra-pancreatic cohort.
- The lung classification by mitotic count and necrosis, rather than Ki-67, still governs treatment, and the two systems are being reconciled.

## Open problems

- No randomised trial has tested somatostatin analogues or radioligand therapy specifically in lung neuroendocrine tumours.
- Lung and gastroenteropancreatic grading systems disagree, so trial eligibility and guideline advice do not map cleanly.
- Atypical carcinoids relapse late and there is no proven adjuvant therapy.

## Notes

- Where carcinoid sits in the lung family. The 2021 WHO classification of thoracic tumours puts typical carcinoid, atypical carcinoid, large cell neuroendocrine carcinoma and small cell carcinoma in one neuroendocrine chapter, so the neuroendocrine spectrum crosses the clinical small-cell and non-small-cell split that organises the rest of the lung family. This corpus keeps the carcinoids under the neuroendocrine family page, where the somatostatin-analogue and peptide receptor radionuclide pages sit beside them, and keeps small cell carcinoma and large cell neuroendocrine carcinoma under lung cancer; all three are cross-linked. The reasoning is set out in the taxonomy section of docs/CANCER-PAGES.md.

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Neuroendocrine_tumor
- RADIANT-4 (Lancet 2016): https://doi.org/10.1016/S0140-6736(15)00817-X
- CABINET (NEJM 2024): https://doi.org/10.1056/NEJMoa2403991
- Wikipedia: https://en.wikipedia.org/wiki/Neuroendocrine_tumor
- Nicholson, J Thorac Oncol 2022: the 2021 WHO classification of lung tumours, impact of advances since 2015: https://doi.org/10.1016/j.jtho.2021.11.003

## Connected records

- cancers: [Extrapulmonary neuroendocrine carcinoma](https://onco.cc/cancers/extrapulmonary-nec/), [Grade 3 well-differentiated neuroendocrine tumour](https://onco.cc/cancers/grade-3-net/), [Large cell carcinoma of the lung](https://onco.cc/cancers/large-cell-lung-carcinoma/), [Large cell neuroendocrine carcinoma of the lung](https://onco.cc/cancers/lung-lcnec/), [Lung cancer (all types)](https://onco.cc/cancers/lung-cancer/), [Multiple endocrine neoplasia type 1 (MEN1)](https://onco.cc/cancers/men1-syndrome/), [Neuroendocrine tumours](https://onco.cc/cancers/neuroendocrine/), [Pancreatic neuroendocrine tumours](https://onco.cc/cancers/pancreatic-net/), [Small intestinal neuroendocrine tumours](https://onco.cc/cancers/small-intestinal-net/), [Small-cell lung cancer](https://onco.cc/cancers/sclc/), [Thymoma (WHO types A, AB, B1, B2 and B3)](https://onco.cc/cancers/thymoma/)
- technologies: [CT (computed tomography)](https://onco.cc/technologies/ct/), [Peptide receptor radionuclide therapy (PRRT)](https://onco.cc/technologies/prrt/), [Robotic & minimally invasive surgery](https://onco.cc/technologies/robotic-surgery/), [Somatostatin receptor PET (68Ga/64Cu-DOTATATE)](https://onco.cc/technologies/sstr-pet/)
- terms: [Bronchoscopy (EBUS, robotic navigation)](https://onco.cc/terms/bronchoscopy/), [Carcinoid syndrome and carcinoid heart disease](https://onco.cc/terms/carcinoid-syndrome/), [Chromogranin A](https://onco.cc/terms/chromogranin-a/), [Lobectomy](https://onco.cc/terms/lobectomy/), [Neuroendocrine tumour grade (Ki-67) and WHO classification](https://onco.cc/terms/net-grade-ki67/), [TNM 9: what changed in lung cancer staging](https://onco.cc/terms/tnm-9-lung-cancer/), [TTF-1 and p40 (how lung histology is decided)](https://onco.cc/terms/ttf1-p40/)
- targets: [mTOR](https://onco.cc/targets/mtor/), [Somatostatin receptor 2](https://onco.cc/targets/sstr2/)
- drugs: [Cabozantinib](https://onco.cc/drugs/cabozantinib/), [Capecitabine + temozolomide (CAPTEM)](https://onco.cc/drugs/capecitabine-temozolomide/), [Everolimus](https://onco.cc/drugs/everolimus/), [Gallium-68 DOTATATE (and Cu-64 DOTATATE)](https://onco.cc/drugs/ga68-dotatate/), [Lutetium-177 dotatate](https://onco.cc/drugs/lutathera/), [Pasireotide](https://onco.cc/drugs/pasireotide/), [Somatostatin analogues (octreotide, lanreotide)](https://onco.cc/drugs/octreotide-lanreotide/)
- trials: [CABINET (Alliance A021602)](https://onco.cc/trials/cabinet/), [CLARINET](https://onco.cc/trials/clarinet/), [RADIANT-3 and RADIANT-4](https://onco.cc/trials/radiant-3-4/), [SPINET](https://onco.cc/trials/spinet/), [Study to Evaluate the Efficacy and Safety of Lutathera in Patients With Grade 2 and Grade 3 Advanced GEP-NET](https://onco.cc/trials/nct03972488/), [Zanzalintinib Versus Everolimus in Participants With Locally Advanced or Metastatic Neuroendocrine Tumors](https://onco.cc/trials/nct06943755/)
- key papers: [CABINET (Alliance A021602): cabozantinib for advanced neuroendocrine tumours](https://onco.cc/key-papers/paper-cabinet-cabozantinib-nejm-2024/), [ENETS expert consensus on pulmonary neuroendocrine (carcinoid) tumours](https://onco.cc/key-papers/paper-enets-lung-net-consensus-caplin-ann-oncol-2015/), [RADIANT-4: everolimus for advanced non-functional neuroendocrine tumours of the lung or gastrointestinal tract](https://onco.cc/key-papers/paper-radiant-4-everolimus-lancet-2016/)
- people: [Jennifer A. Chan](https://onco.cc/people/jennifer-chan/)
- biomarkers: [Ki-67 index (proliferation by IHC)](https://onco.cc/biomarkers/ki-67-index/), [Somatostatin receptor expression by PET (SSTR-positive)](https://onco.cc/biomarkers/sstr-pet-expression/)

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JSON: https://onco.cc/api/v1/entities/lung-net.json