Immunotherapy has become an important part of lung cancer treatment, but it is not used in every patient or at every stage. Whether immunotherapy is appropriate depends on the type of lung cancer, its stage, molecular characteristics, PD-L1 status, whether surgery is possible, and the treatments already given.
In recent years, immunotherapy has been incorporated into treatment plans for both non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC). If you are exploring the broader role of this treatment, our Cancer Immunotherapy guide explains how immunotherapy works and the different approaches used in cancer care.
The important point is that immunotherapy is not simply a treatment reserved for the final stages of lung cancer. Depending on the situation, it may be considered before or after surgery, after chemoradiation, or as part of treatment for advanced disease.
*AI-generated image - for illustration only. Clinical accuracy is not guaranteed.
When Is Immunotherapy Used for Non-Small Cell Lung Cancer?
NSCLC is the most common type of lung cancer and includes several subtypes, such as adenocarcinoma and squamous cell carcinoma. Immunotherapy may be used at different points in the treatment journey.
1. Before and After Surgery
For some patients with potentially resectable NSCLC, immunotherapy can be combined with chemotherapy before surgery. This is called neoadjuvant or perioperative treatment. The aim is to treat cancer cells throughout the body while also helping reduce or control the primary tumour before surgery.
*AI-generated image - for illustration only. Clinical accuracy is not guaranteed.
In selected patients, immunotherapy may then continue after surgery as part of the postoperative treatment plan. The exact approach depends on factors such as the stage of cancer, whether the tumour can be completely removed, molecular test results, and the specific immunotherapy regimen being considered.
2. Stage III NSCLC That Cannot Be Surgically Removed
Some patients with stage III NSCLC have locally advanced disease that cannot be treated with surgery. When the cancer has not progressed after concurrent platinum-based chemotherapy and radiation therapy, durvalumab may be used as consolidation immunotherapy.
Here, immunotherapy is given after the initial chemoradiation rather than replacing it. The goal is to continue controlling cancer that remains after the first course of treatment.
3. Advanced or Metastatic NSCLC
Immunotherapy has a particularly established role when NSCLC has spread to distant parts of the body or cannot be treated with surgery or curative radiation alone. Depending on the individual situation, immunotherapy may be given:
- On its own
- In combination with chemotherapy
- In combination with another immunotherapy drug and chemotherapy
Why Does PD-L1 Testing Matter?
PD-L1 is a protein that can be present on cancer cells or cells around a tumour. Some lung cancers use the PD-1/PD-L1 pathway to reduce the immune system's ability to attack them.
PD-L1 testing can therefore provide useful information when doctors are deciding whether an immune checkpoint inhibitor should be used, particularly in advanced NSCLC. A higher level of PD-L1 can support the use of certain immunotherapy approaches, although PD-L1 is not the only factor that determines treatment.
*AI-generated image - for illustration only. Clinical accuracy is not guaranteed.
A patient with low or absent PD-L1 expression may still receive an immunotherapy-containing regimen in some situations, particularly when immunotherapy is combined with chemotherapy.
Conversely, a high PD-L1 result does not automatically mean that immunotherapy is the right treatment. The cancer's genetic profile, stage, overall treatment plan, and the patient's health also matter.
This is why PD-L1 testing should be considered alongside, rather than separately from, broader biomarker and molecular testing.
When Is Immunotherapy Used for Small Cell Lung Cancer?
Small cell lung cancer behaves differently from NSCLC, so the role and timing of immunotherapy are also different.
Extensive-Stage Small Cell Lung Cancer
For newly diagnosed extensive-stage SCLC, immunotherapy is commonly combined with platinum-based chemotherapy and etoposide as an initial treatment. Atezolizumab or durvalumab may be used as part of these treatment regimens.
In this setting, chemotherapy attacks rapidly dividing cancer cells while immunotherapy works through the immune system. Immunotherapy may then continue as maintenance treatment after the initial chemotherapy portion, depending on the regimen and the patient's response and tolerance.
Limited-Stage Small Cell Lung Cancer
The role of immunotherapy in limited-stage SCLC has also expanded. For adults whose limited-stage disease has not progressed following concurrent platinum-based chemotherapy and radiation therapy, durvalumab may be used as consolidation treatment.
This means immunotherapy is given after the initial chemoradiation rather than as a replacement for it. The approach is intended to help maintain control of the cancer after it has responded to initial treatment.
Can Immunotherapy Be Used If Lung Cancer Comes Back?
Recurrent lung cancer does not automatically mean that immunotherapy will be used. The decision depends on the type of lung cancer, where it has returned, previous treatments, how long the cancer remained controlled, biomarker results, and the patient's overall condition.
For recurrent or previously treated disease, immunotherapy may be an option in selected circumstances. Other possibilities can include chemotherapy, targeted therapy when an actionable molecular alteration is present, radiation, local treatments, or a clinical trial.
Previous exposure to immunotherapy is also important. A treatment that may be appropriate when cancer is first diagnosed is not necessarily appropriate after the cancer has progressed following the same type of treatment.
What Determines Whether Immunotherapy Is Appropriate?
There is no single test that answers this question for every patient. Doctors generally consider several pieces of information together:
- Type of lung cancer: NSCLC and SCLC have different treatment pathways.
- Stage: Immunotherapy can have a role in selected early, locally advanced, and metastatic cancers.
- Surgical eligibility: Some patients receive immunotherapy before or after surgery, while others are treated without surgery.
- PD-L1 expression: This can help guide the choice of certain immunotherapy approaches.
- Molecular alterations: Tests for changes such as EGFR and ALK can influence whether targeted therapy should be considered instead of, or before, an immunotherapy-based strategy.
- Previous treatment: Chemotherapy, radiation, surgery, targeted therapy, and previous immunotherapy all affect subsequent choices.
- Overall health: Existing medical conditions and the ability to tolerate treatment are also considered.
Is Immunotherapy Always Given With Chemotherapy?
No. Immunotherapy can be given alone in selected situations, but it is also frequently combined with chemotherapy or another immunotherapy drug.
For example, some patients with advanced NSCLC may receive an immune checkpoint inhibitor alone when their tumour has characteristics that make this approach appropriate. Other patients may receive immunotherapy together with chemotherapy because the combination provides a broader treatment strategy.
In SCLC, immunotherapy is commonly incorporated into combination treatment with chemotherapy in extensive-stage disease. The appropriate combination depends on the cancer type, stage, treatment history, and approved treatment options.
What Side Effects Can Occur?
Immunotherapy side effects are different from many of the effects typically associated with chemotherapy because they can result from the immune system becoming overactive and affecting healthy tissues.
Common problems can include fatigue, skin changes, itching, diarrhoea, nausea, reduced appetite, or changes in thyroid function. Less commonly, inflammation can affect organs such as the lungs, liver, intestines, kidneys, heart, or other parts of the body.
Because immune-related side effects can sometimes become serious, new or unusual symptoms during treatment should be reported promptly. Treatment may involve temporarily stopping immunotherapy and, when appropriate, using medicines to control the immune reaction.
*AI-generated image - for illustration only. Clinical accuracy is not guaranteed.
Does Everyone With Lung Cancer Need Immunotherapy?
No. Immunotherapy is one part of a much broader range of lung cancer treatments. Some patients may benefit more from surgery, radiation therapy, chemotherapy, targeted therapy, or a combination of treatments.
For others, immunotherapy may become an important component of treatment. In some cases, a clinical trial may also provide access to an emerging treatment strategy. The decision is therefore based on the individual cancer rather than simply on the diagnosis of “lung cancer.”
The Bottom Line
Immunotherapy for lung cancer is no longer limited to one stage or one type of disease. It may be used before or after surgery in selected NSCLC patients, after chemoradiation for certain locally advanced cancers, or as part of treatment for advanced NSCLC and extensive-stage SCLC. Its role has also expanded to selected patients with limited-stage SCLC following chemoradiation.
The right time to use immunotherapy depends on the complete picture: cancer type and stage, PD-L1 expression, molecular test results, treatment history, surgical options, and overall health. Understanding these factors helps explain why two people with lung cancer may receive very different treatment plans.
