Small cell lung cancer is a type of lung cancer that grows fast and often spreads early to other parts of the body; smoking is its main risk factor [1]. About 1 in 7 lung cancers are of this type [2]. The main treatment is chemotherapy: in limited stage together with radiotherapy to the chest followed by the immunotherapy drug durvalumab, and in extensive stage together with the immunotherapy drug atezolizumab or durvalumab [1, 3, 4, 5]. This cancer usually responds well to treatment at first but often comes back, so a cure is hard to achieve and is possible mainly in limited stage [1, 2].
Key points
- Small cell lung cancer grows fast and spreads early; smoking is its main risk factor [1].
- It has two main stages: limited (on one side of the chest) and extensive (spread). At diagnosis, only about 1 in 3 people have limited-stage disease [1, 2].
- It responds to chemotherapy and radiotherapy better than other types of lung cancer, but it often comes back [2].
- In limited stage, chemotherapy and radiotherapy given together followed by the immunotherapy drug durvalumab helped people live longer: half of the patients lived more than four and a half years [3].
- In extensive stage, adding immunotherapy to chemotherapy roughly tripled the number of people alive 3 years later [6].
- Stopping smoking after diagnosis improves the chance of survival [10].
What is small cell lung cancer and why does it grow so fast?
There are two main types of lung cancer: non-small cell, which is more common, and small cell [1]. The name "small cell" comes from how the cancer cells look under a microscope. These cells divide quickly and often reach other parts of the body early in the disease [1]; so at diagnosis, in about 2 in 3 people the cancer has already spread outside the chest [2].
The main risk factor is smoking cigarettes, pipes or cigars; the earlier someone started, and the more and the longer they smoked, the higher the risk. Second-hand smoke, radon gas, asbestos and air pollution also raise the risk [1].
Its symptoms are like those of other lung cancers: a cough that does not go away or gets worse, shortness of breath, wheezing, chest pain, coughing up blood-stained mucus, a hoarse voice, difficulty swallowing, loss of appetite, weight loss without a reason, severe tiredness and swelling of the face and the veins in the neck [1]. Read more: symptoms of lung cancer.
Limited vs extensive stage: what do they mean?
| Stage | What it means | Main treatment |
|---|---|---|
| Limited | The cancer is in the lung where it started and may have spread to the area between the lungs or to the lymph nodes above the collarbone; all of it can be covered by radiotherapy to one area [1, 2] | Chemotherapy and radiotherapy to the chest together, then the immunotherapy drug durvalumab [1] |
| Extensive | The cancer has reached other parts of the body (such as the liver, bones or brain) or the fluid around the lung, or is too widespread to be covered by radiotherapy to one area [1, 2] | Chemotherapy with immunotherapy (atezolizumab or durvalumab) [1] |
Doctors today also use TNM staging (stages 1 to 4); limited stage roughly matches stages 1 to 3 and extensive stage matches stage 4 [2].
To find the stage, people usually have a CT scan of the chest and upper abdomen, a bone scan and an MRI scan of the brain (or a CT scan of the brain); a PET scan can sometimes show the stage more accurately [2]. Read more: What is a PET scan? and cancer stages.
Treating limited-stage disease
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Durvalumab immunotherapy
If the disease has not grown after chemotherapy and radiotherapy, durvalumab is given every 4 weeks for up to 2 years [1, 3]. In a large study this treatment helped people live longer, and half of the patients lived more than four and a half years; serious side effects were about the same in both groups [3].
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Preventive brain radiotherapy
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Surgery, only in certain cases
In some people with limited-stage disease, surgery is done, followed by chemotherapy or chemoradiotherapy [1].
Treating extensive-stage disease
The first treatment is chemotherapy with immunotherapy: carboplatin (or cisplatin) and etoposide with atezolizumab or durvalumab, usually 4 cycles every 3 weeks, followed by immunotherapy on its own [1, 4, 5]. In two large studies, adding immunotherapy helped people live longer [4, 5]; the number of people alive 3 years later roughly tripled [6].
Radiotherapy is also used: to the chest if the cancer has responded to chemotherapy, and to the brain, bones or other places to ease pain and other symptoms [1]. In extensive stage, instead of preventive brain radiotherapy, the brain can be watched with regular MRI scans; in one study the two approaches gave similar survival [9]. Read tips for the first treatment in your first chemotherapy session and about immunotherapy side effects in side effects of immunotherapy.
If the cancer comes back
Repeating the same chemotherapy
If the cancer has come back at least 3 months after the first treatment ended, repeating carboplatin and etoposide controlled the disease for longer than the drug topotecan in one study [11].
Other chemotherapy
Topotecan and other chemotherapy drugs are common options after the cancer comes back [2].
Tarlatamab, a new immunotherapy
Tarlatamab is a drug that links the body's immune cells to the cancer cells [2]. In a large study of people whose cancer had grown after their first chemotherapy, those given tarlatamab lived longer than those given chemotherapy and had fewer serious side effects [7]. Its most common side effect is a reaction called "cytokine release syndrome", which happened mostly after the first 1 or 2 doses and was controlled with supportive treatment [2].
Is small cell lung cancer curable? What is the life expectancy?
Without treatment this cancer progresses very quickly, so treatment should start early [2]. It responds well to chemotherapy and radiotherapy, but for most people current treatments do not cure it and it often comes back [1, 2].
- Limited stage: with chemotherapy and radiotherapy together followed by durvalumab, half of the patients lived more than four and a half years [3].
- Extensive stage: with chemotherapy plus immunotherapy, half of the patients lived about a year or longer [4, 5], and nearly 2 in 10 were alive 3 years later [6].
These numbers are averages from many patients and cannot say exactly what will happen to one person. For a comparison with non-small cell lung cancer, read Is lung cancer curable?
When should I contact a doctor?
See a doctor if you have a cough that does not go away or gets worse, blood-stained mucus, shortness of breath, weight loss without a reason or a hoarse voice, especially if you smoke or used to smoke [1].
Get help straight away or call your local emergency number if you have:
- swelling of the face with swollen veins in the neck [1, 2]
- a change in behaviour or personality, or weakness or numbness in an arm or leg; this may mean the cancer has reached the brain [2]
- severe shortness of breath or a lot of blood in your mucus [1]
If you are having chemotherapy, take a fever seriously and tell your team at once: low blood counts and preventing infection.
Frequently asked questions
How does small cell lung cancer differ from non-small cell lung cancer?
Small cell lung cancer is less common, grows faster and spreads earlier [1]. It responds better to chemotherapy and radiotherapy but comes back more often [2]. So its treatment is mostly chemotherapy, radiotherapy and immunotherapy, and surgery is used only in some people with limited-stage disease [1].
Can small cell lung cancer be cured?
A cure is hard to achieve because this cancer has usually spread by the time it is diagnosed [2]. The best chance is in limited stage, with chemotherapy and radiotherapy together followed by immunotherapy [1, 3]. In extensive stage, treatment also helps people live longer, and some people live for years [6].
Do I need preventive brain radiotherapy?
In people whose cancer has disappeared completely with treatment, this radiotherapy lowers the risk of cancer reaching the brain and has helped people live a little longer [8]. In extensive stage, one study showed that if the brain is checked with regular MRI scans, preventive radiotherapy does not help people live longer [9]. Make the decision with your doctor.
Is stopping smoking still worthwhile after diagnosis?
Yes. In people with limited-stage disease, continuing to smoke was linked to a higher risk of death, of the cancer coming back and of a new cancer; the chance of living 5 years was estimated to be about twice as high in those who stopped as in those who carried on [10]. Stopping before chemotherapy and radiotherapy start is recommended [2]. Read: stopping smoking.
Do I need genetic testing of the tumour?
The first treatment for this cancer is chemotherapy, alone or with immunotherapy, not a targeted tablet [1]. Your doctor may suggest tests on the tumour sample (biomarker tests) to help predict the response to some immunotherapy drugs [1]. Non-small cell lung cancer is different: tumour genetic testing and targeted therapy.
Staging and key treatment evidence (for doctors)
For physicians
Epidemiology and staging. SCLC accounts for about 15% of bronchogenic carcinomas; at diagnosis about 30% have limited-stage disease (LD: hemithorax of origin, mediastinum or supraclavicular nodes, encompassable within a tolerable radiotherapy port) and about two thirds have clinical evidence of metastases. The 9th edition of the AJCC recommends TNM staging; LD corresponds to any T (except T3–4 due to multiple lung nodules that do not fit in a tolerable radiation field), any N and M0, i.e. stages I to IIIB; extensive-stage disease (ED) is stage IV with M1, including malignant pleural effusion. Staging: CT of the chest and upper abdomen, bone scan, brain MRI (or CT) and, in selected patients, bone marrow aspiration; PET may change the stage and the radiation field. Untreated, median survival is 2 to 4 months; overall 5-year survival across all patients is 5% to 10%; in LD, median survival is 16 to 24 months and 5-year survival 14% [2].
Limited-stage disease. Concurrent chemoradiotherapy with platinum–etoposide; in one trial, 45 Gy twice daily over 3 weeks versus 45 Gy once daily over 5 weeks gave 5-year survival of 26% vs 16% (P=0.04), with more oesophagitis [2]. ADRIATIC: durvalumab 1500 mg every 4 weeks for up to 24 months after chemoradiotherapy without progression; median overall survival 55.9 vs 33.4 months (HR 0.73; 98.321% CI 0.54 to 0.98) and PFS 16.6 vs 9.2 months (HR 0.76); grade 3–4 adverse events 24.4% vs 24.2%; grade 3–4 pneumonitis 3.1% vs 2.6% [3]. PCI in complete response (meta-analysis of 7 trials, 987 patients): RR of death 0.84, 3-year survival 20.7% vs 15.3% and RR of brain metastases 0.46 [8]; the standard dose is 25 Gy in 10 fractions (RTOG 0212) [2].
Extensive-stage disease. IMpower133: atezolizumab with carboplatin–etoposide (4 cycles of 21 days, then maintenance); median overall survival 12.3 vs 10.3 months (HR 0.70; 95% CI 0.54 to 0.91) [4]. CASPIAN: durvalumab 1500 mg with etoposide 80 to 100 mg/m² on days 1 to 3 and carboplatin AUC 5 to 6 or cisplatin 75 to 80 mg/m², every 3 weeks for up to 4 cycles, then durvalumab 1500 mg every 4 weeks; median overall survival 13.0 vs 10.3 months (HR 0.73) [5], and at a median follow-up of 39.4 months, 3-year survival 17.6% vs 5.8% (HR 0.71) [6]. In ED with any response to chemotherapy and a negative brain MRI, PCI did not improve survival compared with MRI surveillance (median 11.6 vs 13.7 months; HR 1.27; 0.96 to 1.68; stopped early for futility) [9]. Regimens and doses: carboplatin–etoposide with atezolizumab or durvalumab.
Relapse. In sensitive relapse (≥90 days after the end of first-line treatment), carboplatin AUC 5 on day 1 and etoposide 100 mg/m² on days 1 to 3 (6 cycles) versus oral topotecan 2.3 mg/m² on days 1 to 5: median PFS 4.7 vs 2.7 months (HR 0.57) [11]. DeLLphi-304: tarlatamab versus chemotherapy (topotecan, lurbinectedin or amrubicin) after platinum; median overall survival 13.6 vs 8.3 months (HR 0.60; 95% CI 0.47 to 0.77) and grade ≥3 adverse events 54% vs 80% [7]. Continued smoking in LD-SCLC was associated with an HR for death of 1.86 (1.33 to 2.59) and an HR for a second primary tumour of 4.31; modelled 5-year survival was 63% in quitters versus 29% [10].
Scientific evidence
Scientific evidence
4 itemsFirst-Line Atezolizumab plus Chemotherapy in Extensive-Stage Small-Cell Lung Cancer
Durvalumab after Chemoradiotherapy in Limited-Stage Small-Cell Lung Cancer
Durvalumab plus platinum–etoposide versus platinum–etoposide in first-line treatment of extensive-stage small-cell lung cancer (CASPIAN): a randomised, controlled, open-label, phase 3 trial
Tarlatamab in Small-Cell Lung Cancer after Platinum-Based Chemotherapy
Related cancer types
Related questions
References
11 referencesShow all references, 4 with a study cardClose the reference list
Numbers in the text, such as [1], refer to these sources. Sources with a “Study card” button are summarised in the site’s evidence library.
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- 7Tarlatamab in Small-Cell Lung Cancer after Platinum-Based Chemotherapy
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