Understanding How Immunotherapy Works
- Only some lung cancer patients benefit, especially those with PD-L1 protein on their cells, as it responds well to immunotherapy.
- Clinical trials are exploring new targets beyond PD-L1, potentially expanding immunotherapy’s reach.
- Immunotherapy enables white blood cells to recognize and attack cancer cells, which often evade the immune system.
- PD-L1 testing is essential for determining the suitability of immunotherapy, especially in NSCLC cases.
- Not all patients respond to immunotherapy; initially used in advanced stages, it’s now being considered earlier in treatment.
At the moment, only a certain segment of lung cancer patients benefit from immunotherapy.
For instance, people with a protein called PD-L1 on their cancer cells respond well to immunotherapy drugs that block the protein, thus unleashing the immune system to recognize and attack cancer cells. PD-L1 is just one of dozens of different molecules that play a role in how cancer interacts with and evades the immune system.
Read MoreUnderstanding immunotherapy
The immune system uses its white blood cells to attack cells in the body that are abnormal or foreign. Cancerous cells have the ability to prevent the immune system from doing its job. The cancer produces certain proteins to protect the tumor from white blood cells. As a result, the body does not recognize the tumor as abnormal.Immunotherapy drugs stop this from happening and ensure the white blood cells recognize the cancer cell properly and attack it. The cancer cells themselves are not necessarily difficult to fight. However, they continue to divide rapidly. So, immunotherapy drugs help a patient’s immune system control their cancer on its own before it can spread.
Unfortunately, immunotherapy does not work for every patient. It was initially only used for very advanced stages (Stage IV).
However, it is becoming more commonly used as a treatment option in earlier disease progression (Stage III). Immunotherapy treatments are being used in non-small cell lung cancer (NSCLC) stages three and four, as well as in extensive stage small cell lung cancer (SCLC).
When first approved, immunotherapy was only used in patients who had failed other treatment options, but now it can be part of one’s initial treatment as long as the disease is at an advanced stage (stages III or IV). The type of cancer and the specific way the cancer interacts with the immune system determines whether immunotherapy is a viable option.
Keytruda
Keytruda (pembrolizumab) is an immunotherapy drug used to treat certain types of lung cancer by helping the immune system detect and combat cancer cells. Currently, it is offered to patients with a type of lung cancer called non-small cell lung cancer (NSCLC) and can be used with some chemotherapies as a first treatment when:
- The lung cancer has spread
- It is a specific type called non-squamous, and doesn’t have an abnormal EGFR (epidermal growth factor receptor) or ALK (anaplastic lymphoma kinase) gene.
- Some chemotherapies for advanced disease with a type of lung cancer called squamous.
The full list of approvals can be found here.
RELATED: Immunotherapy Drug Keytruda Gets Expanded Approval for Common Lung Cancer
Opdivo Yervoy Combo
The Opdivo (nivolumab) and Yervoy (ipilimumab) combination is an immunotherapy treatment typically recommended for patients with advanced non-small cell lung cancer, particularly those with specific genetic markers or characteristics. It is often as alternative to traditional treatments like chemotherapy and can be used for first-line treatment for patients with:
- Metastatic non-small cell lung cancer (NSCLC) whose tumors express PD-L1, with no EGFR or ALK genomic tumor aberrations.
- Patients with metastatic or recurrent NSCLC without certain tumor markers who have had 2 cycles of chemotherapy.
The full list of approvals can be found here.
Why PDL 1 testing is important in lung cancer
Let’s back up a bit and explain exactly what PDL-1, short for Programmed Death-Ligand 1, is and why its an important factor in deciding on immunotherapy for lung cancer treatment.
PDL-1 is a protein that some lung cancer cells produce to evade the immune system. Blocking PDL-1 helps the immune system recognize and attack these cancer cells more effectively.
If you were recently diagnosed with lung cancer, your oncologist and/or multidisciplinary healthcare team should discuss PD-L1 testing with you and what it may entail. This is important for a lot of reasons:
- If you have NSCLC, your doctor will recommend PD-L1 testing to understand if you can be treated with a type of cancer drug called immune checkpoint inhibitors.
- About a third of patients with late-stage NSCLC have high levels of PD-L1 and can potentially benefit from a treatment option called immunotherapy.
- If your cancer has certain genetic mutations, immune therapy may still work, but your doctor will recommend targeted therapy first and foremost.
- As your own best advocate during treatment, be sure to discuss PD-L1 testing as well as genetic mutation testing with your oncologist and/or healthcare team.
PD-L1 Testing Guidelines
Here are the key points about PD-L1 testing guidelines:
- PD-L1 Testing in Cancer: This test identifies if specific therapies targeting the PD-L1 interaction are suitable, mainly in lung cancer and other types like melanoma and bladder cancer.
- Biopsy for PD-L1 Levels: A biopsy, which can be fine needle, surgical, or core needle, obtains tumor samples to test PD-L1 levels, depending on factors like tumor type and patient age.
- Biopsy Risks: Common risks include tenderness, bleeding, and bruising at the procedure site, with a possible risk of infection.
- Procedure Preparation: Preparation varies; local anesthetic may require no fasting, while general anesthesia does. Anti-anxiety medication might be offered for nervous patients.
Understanding your test results
This test will provide you with the level of PD-L1 in your cancerous tumor cells usually as a percentage. The results will help guide your treatment choices.
- High PD-L1 and Immunotherapy: High PD-L1 levels, especially over 50%, often indicate effectiveness of specific immunotherapy drugs, potentially avoiding chemotherapy.
- Low PD-L1 and Treatment Options: Low PD-L1 may limit options for PD-1/PD-L1 pathway-targeted treatments, but other therapies are available.
- Over 50% PD-L1: For PD-L1 levels over 50%, immunotherapy alone is often viable, with several drug options available.
- Below 50% PD-L1: If PD-L1 is under 50%, treatment usually combines chemotherapy with specific immunotherapy drugs, tailored to cancer type.
_____________________________________________________________________________________________
Dr. Ronald Natale is director of the Lung Cancer Clinical Research Program at the Samuel Oschin Comprehensive Cancer Institute, Cedars-Sinai Medical Center in Los Angeles. Read More
Learn more about SurvivorNet's rigorous medical review process.
