Sinonasal undifferentiated carcinoma (SNUC) and SWI/SNF-deficient sinonasal carcinoma
Sinonasal undifferentiated carcinoma is a rare, fast-growing cancer of the nasal cavity and sinuses made of primitive cells with no clear line of differentiation, most carrying an IDH2 mutation. It presents as a large mass pressing on the eye or brain and is treated with chemotherapy first, then surgery or chemoradiotherapy depending on response; SMARCB1- or SMARCA4-deficient tumours are separate.
Overview
Sinonasal undifferentiated carcinoma was defined in 1986 as a high-grade carcinoma of the sinonasal tract without squamous or glandular differentiation, negative for EBV and for the neuroendocrine and NUT markers that define its mimics. Genomic studies from 2017 found IDH2 R172 mutations in most cases, giving the tumour a molecular identity and a possible drug target; the 2022 WHO classification also carved out SMARCB1 (INI1)-deficient and SMARCA4-deficient sinonasal carcinomas, which look similar but are driven by loss of SWI/SNF chromatin remodelling proteins, and NUT carcinoma, which has its own page. All present late with a bulky mass causing nasal obstruction, proptosis, diplopia or headache, invading the orbit, skull base and dura, and about a fifth have neck node metastases at diagnosis.
Historically, surgery followed by radiotherapy cured few patients because of the extent of disease, and the MD Anderson group changed the paradigm by giving chemotherapy first. In their series of 95 patients (Journal of Clinical Oncology 2019), those whose tumour responded to induction platinum-etoposide did better with definitive chemoradiotherapy than with surgery, while those who did not respond did better with surgery followed by radiotherapy or chemoradiotherapy, so the response to induction now decides the local treatment. Intensity-modulated or proton radiotherapy is used to spare the optic pathways and brain, and elective neck treatment is standard because nodal relapse is common. Metastatic disease is treated with platinum-etoposide as for neuroendocrine carcinoma, and PD-1 antibodies have produced responses in case series of SMARCB1-deficient and other sinonasal carcinomas. The IDH2 inhibitor enasidenib, approved for IDH2-mutant leukaemia, is being tested in IDH2-mutant sinonasal carcinoma, and EZH2 inhibitors, active in other SMARCB1-deficient tumours, are being explored for the SWI/SNF-deficient group. Five-year survival remains low overall, and referral to a skull base centre with molecular pathology is recommended for every patient.
State of the art
- Response to induction chemotherapy now decides between surgery and chemoradiotherapy.
- IDH2 mutations give the tumour an identity and a drug target.
- SWI/SNF-deficient carcinomas have been separated as distinct diseases with their own emerging therapies.
Red cards
From the labels and guidelines behind the standard of care. Your team's thresholds win.- Emergency services nowBleeding or bruising
Bleeding that will not stop, black or bloody stools, or unexplained bruising when platelets are expected to be low.
- Emergency services nowHypophysitis or adrenal crisis
Persistent headache with extreme tiredness, nausea, dizziness on standing or low blood pressure. Vomiting, severe weakness or collapse is adrenal crisis.
- Emergency services nowDifferentiation syndrome
Fever, cough or breathlessness, rapid weight gain or swelling, bone pain, low blood pressure or reduced urine; the labels say to start steroids and monitor at the first suspicion, and the syndrome has been fatal.
- Check before combiningFood and drink: Pembrolizumab
No pharmacokinetic interactions expected (antibody). See the irAE guide for toxicity management.
- Check before combiningKidneys: Cisplatin
Dose reduce or avoid for CrCl below 60 (carboplatin is the alternative).
- Check before combiningKidneys: Etoposide
Reduce to 75% for CrCl 15-50.
See all on the product pages:CisplatinEnasidenibEtoposideNivolumabPembrolizumabPlatinum + etoposide (EP / CE)·Printable cards in the navigator
Anatomy and lymph node drainage
- Oral cavity and tongue
- Oropharynx: tonsil, base of tongue (HPV)
- Nasopharynx (EBV)
- Larynx and hypopharynx
- Parotid and other salivary glands
- Thyroid
- Nodes: level I (submandibular)
- Nodes: level II (upper jugular)
- Nodes: level III-IV (jugular)
- Nodes: level V (posterior)
- Nodes: level VI (central, thyroid)
- Nodes: retropharyngeal (nasopharynx)
Site decides cause and behaviour: HPV drives oropharyngeal cancer, EBV drives nasopharyngeal cancer, tobacco drives oral and laryngeal cancer; all drain into the neck node levels that surgeons and radiotherapists map.
- Oral cavity and tongue
- Oropharynx: tonsil, base of tongue (HPV)
- Nasopharynx (EBV)IDH2-mutant sinonasal undifferentiated carcinoma (the majority; enasidenib in trials) · IDH2 wild-type sinonasal undifferentiated carcinoma · SMARCB1 (INI1)-deficient sinonasal carcinoma (SWI/SNF-deficient; separate WHO entity) · SMARCA4-deficient sinonasal carcinoma (SWI/SNF-deficient; separate WHO entity) · Induction-responsive sinonasal undifferentiated carcinoma (definitive chemoradiotherapy) · Induction-refractory sinonasal undifferentiated carcinoma (surgery then radiotherapy)
- Larynx and hypopharynx
- Parotid and other salivary glands
- Thyroid
- level I (submandibular)
- level II (upper jugular)
- level III-IV (jugular)
- level V (posterior)
- level VI (central, thyroid)
- retropharyngeal (nasopharynx)
Same organ: Oropharyngeal cancer (tonsil and base of tongue), Laryngeal and hypopharyngeal cancer, Oral cavity cancer (mouth and tongue), Head and neck squamous cell carcinoma, Nasopharyngeal carcinoma, Salivary gland cancers, Papillary thyroid cancer, Follicular thyroid cancer, Medullary thyroid cancer, Anaplastic thyroid cancer, Thyroid cancer, Nasal cavity and paranasal sinus cancers (including esthesioneuroblastoma), NUT carcinoma (midline carcinoma with NUTM1 rearrangement), Parathyroid carcinoma, Multiple endocrine neoplasia syndromes (MEN1, MEN2, MEN4), HPV-positive oropharyngeal cancer, HPV-negative head and neck squamous cell carcinoma (including HPV-negative oropharyngeal cancer), Recurrent or metastatic head and neck squamous cell carcinoma, Hypopharyngeal cancer, Adenoid cystic carcinoma, Salivary duct carcinoma, Mucoepidermoid carcinoma, Oral tongue and floor of mouth cancer, Buccal mucosa and gingivobuccal cancer (oral cancer in India), Lip cancer, Locoregionally advanced nasopharyngeal carcinoma (stage III to IVA), Recurrent and metastatic nasopharyngeal carcinoma, Esthesioneuroblastoma (olfactory neuroblastoma)
A rare and aggressive sinonasal cancer of middle-aged adults, usually presenting as a large mass invading the orbit or skull base; historically most patients died within a few years, and induction chemotherapy has improved that.
- MRIStandard of care
Nothing recorded yet.
Nothing recorded yet.
Also on OnCo: Symptoms and red flags · Early detection roadmap.
Cases by country
No country-level case numbers. This cancer is not mapped to a GLOBOCAN site.
One section per setting: the options named, what each is for, the trials behind them, the recorded trade-offs and the questions to ask.
Biopsy with immunohistochemistry (cytokeratins, NUT, INI1, SMARCA4, neuroendocrine markers, EBER) and IDH2 testing; MRI and CT of the sinuses, skull base and neck; PET-CT.
Induction chemotherapy with cisplatin and etoposide (or docetaxel-platinum) for two to three cycles.
Definitive chemoradiotherapy with concurrent cisplatin (intensity-modulated or proton), including elective neck irradiation.
Surgical resection where feasible followed by radiotherapy or chemoradiotherapy.
Platinum-etoposide; PD-1 antibodies (pembrolizumab, nivolumab) on case series evidence; enasidenib for IDH2-mutant tumours in trials; EZH2 inhibitors for SWI/SNF-deficient carcinoma in trials.
Subtypes & biomarkers
top- IDH2-mutant sinonasal undifferentiated carcinoma (the majority; enasidenib in trials)
- IDH2 wild-type sinonasal undifferentiated carcinoma
- SMARCB1 (INI1)-deficient sinonasal carcinoma (SWI/SNF-deficient; separate WHO entity)
- SMARCA4-deficient sinonasal carcinoma (SWI/SNF-deficient; separate WHO entity)
- Induction-responsive sinonasal undifferentiated carcinoma (definitive chemoradiotherapy)
- Induction-refractory sinonasal undifferentiated carcinoma (surgery then radiotherapy)
- IDH2 R172 mutation (diagnosis; enasidenib eligibility)
- SMARCB1 (INI1) and SMARCA4 immunohistochemistry (SWI/SNF-deficient carcinomas)
- NUT immunohistochemistry (exclude NUT carcinoma) and EBV (exclude nasopharyngeal-type carcinoma)
- Response to induction chemotherapy on imaging (decides surgery versus chemoradiotherapy)
- Neck node status
- PD-L1 (investigational)
How often this target appears
- 1986Frierson and colleagues define sinonasal undifferentiated carcinoma
- 2014SMARCB1-deficient sinonasal carcinoma described
- 2017IDH2 R172 mutations found in most sinonasal undifferentiated carcinomas
- 2019MD Anderson series: induction response guides local therapy and improves survival
- 2022WHO classification recognises SWI/SNF-deficient sinonasal carcinomas as separate entities
Dated changes read from the records linked to this cancer: approvals, regulatory steps, reported trials, guideline versions and milestones. Newest first; no date is inferred.
All 6 changes by month →- 2026-09-18This recordSinonasal undifferentiated carcinoma (SNUC) and SWI/SNF-deficient sinonasal carcinomaFacts on this page last checked
When this page itself was last checked or edited.
- 2022MilestoneSinonasal undifferentiated carcinoma (SNUC) and SWI/SNF-deficient sinonasal carcinomaWHO classification recognises SWI/SNF-deficient sinonasal carcinomas as separate entities
A milestone in how this cancer is treated.
- 2019MilestonePlatinum + etoposide (EP / CE)MD Anderson series: induction response guides local therapy and improves survival
A milestone in how this cancer is treated.
- 2017MilestoneIDH1 / IDH2IDH2 R172 mutations found in most sinonasal undifferentiated carcinomas
A milestone in how this cancer is treated.
- 2014MilestoneSinonasal undifferentiated carcinoma (SNUC) and SWI/SNF-deficient sinonasal carcinomaSMARCB1-deficient sinonasal carcinoma described
A milestone in how this cancer is treated.
- 1986MilestoneSinonasal undifferentiated carcinoma (SNUC) and SWI/SNF-deficient sinonasal carcinomaFrierson and colleagues define sinonasal undifferentiated carcinoma
A milestone in how this cancer is treated.
What is in development for Sinonasal undifferentiated carcinoma (SNUC) and SWI/SNF-deficient sinonasal carcinoma, drawn from the whole corpus: 0 items. Drugs are grouped by the most advanced trial phase they have reached anywhere; approved treatments sit under standard of care. Technologies are the methods being tested for this cancer, trials are the studies recorded here, and ideas are proposals not yet in a trial.
Nothing recorded in development for this cancer yet.
Open problems and what is being done
No randomised trial exists and the induction-response strategy rests on one centre's series.
Enasidenib's activity in IDH2-mutant sinonasal carcinoma is unproven.
Most patients still die of the disease within a few years.
Orbital and skull base surgery and radiotherapy carry heavy functional costs.
and how the field plans to fix it →What is being done about thisCost and accessAvailable now- Immune checkpoint inhibitorsStandard of care
In trialsNothing recorded yet.
Ideas and roadmapsNothing recorded yet.
Also on OnCo: Financial help · Coverage by country · HTA decisions.
Trials
topTrials recruiting now
Country and place are remembered in this browser only. A postcode is sent to OpenStreetMap's Nominatim service to find coordinates when you press the button; nothing else leaves your device.
Expert centres
topExpert centres
Houston · cancer center | United States | 0 | 6,724 | 95,007 | #2 | ||
Seoul · hospital | South Korea | none recorded | 0 | 1,312 | 17,172 | #3 | |
Rochester, MN · hospital | United States | 0 | 4,511 | 44,748 | #5 | ||
Baltimore · cancer center | United States | 0 | 2,955 | 41,449 | #10 | ||
Berlin · university | Germany | none recorded | 0 | 1,563 | 17,749 | #12 | |
Boston · hospital | United States | 0 | 3,582 | 54,857 | #16 | ||
Heidelberg · cancer center | Germany | none recorded | 0 | 3,456 | 45,745 | #18 | |
Cleveland · hospital | United States | 0 | 2,264 | 29,412 | #20 | ||
Paris · cancer center | France | none recorded | 0 | 1,065 | 15,111 | #21 | |
Seoul · hospital | South Korea | none recorded | 0 | 464 | 3,248 | #22 | |
Manchester · cancer center | United Kingdom | none recorded | 0 | 104 | 2,145 | #23 | |
Amsterdam · cancer center | Netherlands | none recorded | 0 | 1,451 | 25,873 | #45 | |
Shanghai · cancer center | China | none recorded | 0 | 1,678 | 18,354 | #55 | |
Philadelphia · cancer center | United States | 0 | 3,148 | 54,267 | - | ||
Ann Arbor, MI · cancer center | United States | 0 | 2,991 | 29,686 | - |
These are the things we can measure; they are not a ranking of quality. Each column is a field on the institution record or a count over what OnCo has linked; a centre that treats many patients with Sinonasal undifferentiated carcinoma (SNUC) and SWI/SNF-deficient sinonasal carcinoma but is thinly recorded here will look small.
Not known: OnCo holds no case-volume or outcome figures for centres, so none are shown. Where a national audit or registry publishes them, the centre's page links to it. Default order: Newsweek rank, then trials for this cancer, then research output.
Questions to ask
topQuestions to ask your oncologist about Sinonasal undifferentiated carcinoma (SNUC) and SWI/SNF-deficient sinonasal carcinoma
Newly diagnosed
- What is my exact diagnosis, stage, and grade, and which tests established them?Why: Everything else follows from an accurate stage and subtype.
- Which biomarkers have been tested on my tumour (for example IDH2 R172 mutation, SMARCB1and SMARCA4 immunohistochemistry, NUT immunohistochemistryand EBV, Response to induction chemotherapy on imaging, Neck node status), and what were the results?Why: These results decide eligibility for targeted therapy, immunotherapy, and trials.
- Which subtype is my cancer, and does that change the recommended treatment?Why: Recognised subtypes for this cancer include IDH2-mutant sinonasal undifferentiated carcinoma, IDH2 wild-type sinonasal undifferentiated carcinoma, SMARCB1-deficient sinonasal carcinoma.
- Is germline (inherited) genetic testing recommended for me or my family?Why: Inherited variants can change treatment and matter for relatives.
Diagnosis
- For my situation (diagnosis), which of the standard options do you recommend and why?Why: Guideline options include: Biopsy with immunohistochemistry (cytokeratins, NUT, INI1, SMARCA4, neuroendocrine markers, EBER) and IDH2 testing; MRI and CT of the sinuses, skull base and neck; PET-CT.
Locally advanced disease, first step
- For my situation (locally advanced disease, first step), which of the standard options do you recommend and why?Why: Guideline options include: Induction chemotherapy with cisplatin and etoposide (or docetaxel-platinum) for two to three cycles.
- Am I a candidate for Cisplatin, Etoposide, Platinum + etoposide (EP / CE), and what side effects should I expect?Why: Knowing the expected toxicities helps you plan work, family, and supportive care.
Responders to induction
- For my situation (responders to induction), which of the standard options do you recommend and why?Why: Guideline options include: Definitive chemoradiotherapy with concurrent cisplatin (intensity-modulated or proton), including elective neck irradiation.
- Am I a candidate for Cisplatin, and what side effects should I expect?Why: Knowing the expected toxicities helps you plan work, family, and supportive care.
Non-responders to induction
- For my situation (non-responders to induction), which of the standard options do you recommend and why?Why: Guideline options include: Surgical resection where feasible followed by radiotherapy or chemoradiotherapy.
Metastatic or recurrent disease
- For my situation (metastatic or recurrent disease), which of the standard options do you recommend and why?Why: Guideline options include: Platinum-etoposide; PD-1 antibodies (pembrolizumab, nivolumab) on case series evidence; enasidenib for IDH2-mutant tumours in trials; EZH2 inhibitors for SWI/SNF-deficient carcinoma in trials.
- Am I a candidate for Platinum + etoposide (EP / CE), Pembrolizumab, Nivolumab or related drugs, and what side effects should I expect?Why: Knowing the expected toxicities helps you plan work, family, and supportive care.
Any stage
- Are there clinical trials I could join, for example of Enasidenib, Proton therapy, Pembrolizumab?Why: Trials are how the next standard of care is set; asking early keeps options open.
- Would a second opinion at a high-volume centre change anything, and can you help arrange it?Why: Rare or high-stakes decisions benefit from a centre that treats many similar patients.
- What supportive care (symptom control, nutrition, exercise, mental health, financial help) is available from the start?Why: Supportive care improves quality of life and helps patients complete treatment.
- I read that “No randomised trial exists and the induction-response strategy rests on one centre's series”. How does that affect my plan?Why: Open problems are where trials and second opinions matter most.
- I read that “Enasidenib's activity in IDH2-mutant sinonasal carcinoma is unproven”. How does that affect my plan?Why: Open problems are where trials and second opinions matter most.
Newly diagnosed? Read the first 60 days with Sinonasal undifferentiated carcinoma (SNUC) and SWI/SNF-deficient sinonasal carcinoma, then print the one-page appointment sheet with room for the answers.
Print this page for your appointment (your browser's print command). These prompts are for discussion; your clinical team knows your case.
Direct links plus the targets, companies, and technologies of this cancer's products.
technologies
14targets
3drugs
6companies
2terms
3key papers
2Sinonasal undifferentiated carcinoma is treated with induction platinum-etoposide, and the response decides whether the patient is spared radical surgery.
Sinonasal undifferentiated carcinoma can be confirmed by IDH2 testing or mutant-IDH immunohistochemistry rather than diagnosed by exclusion, and IDH2 inhibitors such as enasidenib became rational candidates for trials.
Latest papers
topQuery for this cancer: (TITLE:"Sinonasal undifferentiated carcinoma SNUC and SWI/SNF-deficient sinonasal carcinoma" OR ABSTRACT:"Sinonasal undifferentiated carcinoma SNUC and SWI/SNF-deficient sinonasal carcinoma" OR TITLE:"SNUC" OR ABSTRACT:"SNUC" OR TITLE:"IDH2-mutant sinonasal carcinoma" OR ABSTRACT:"IDH2-mutant sinonasal carcinoma" OR TITLE:"SMARCB1-deficient sinonasal carcinoma" OR ABSTRACT:"SMARCB1-deficient sinonasal carcinoma" OR TITLE:"SMARCA4-deficient sinonasal carcinoma" OR ABSTRACT:"SMARCA4-deficient sinonasal carcinoma" OR TITLE:"Undifferentiated carcinoma of the paranasal sinuses" OR ABSTRACT:"Undifferentiated carcinoma of the paranasal sinuses") AND (treatment OR therapy OR trial OR survival OR diagnosis). Results are unfiltered search hits about Sinonasal undifferentiated carcinoma (SNUC) and SWI/SNF-deficient sinonasal carcinoma, not a curated reading list.
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