Understanding ALK-Positive Lung Cancer: A Beginner's Guide

Medically reviewed by Jerome Albert Ecker | MD, Assistant Professor of Medicine, Duke University - Durham, NC on August 13th, 2023.

Key Takeaways

This genetic subtype occurs when the ALK gene fuses with another gene (most commonly EML4), creating abnormal proteins that drive uncontrolled cell growth in about 3-7% of all lung cancers.
Patients are typically younger (median age 50-52) with little to no smoking history, and tumors often present as adenocarcinoma with signet-ring cell features under microscopy.
Targeted ALK inhibitors like alectinib show 5-year survival rates of 62.5% compared to 45.5% with crizotinib, with newer drugs overcoming resistance mutations that develop over time.
Molecular testing through next-generation sequencing or fluorescence in-situ hybridization (FISH) is essential since standard imaging cannot distinguish this subtype from other lung cancers.
Brain metastases occur in 20-30% of patients at diagnosis, but newer ALK inhibitors like brigatinib and lorlatinib effectively cross the blood-brain barrier for treatment.

If you or a loved one has been diagnosed with ALK-positive lung cancer, you may have many questions. This guide will help you understand what ALK-positive lung cancer is, its symptoms, how it's diagnosed, and the available treatment options. We'll also discuss support resources to help you navigate this challenging time.

What Is ALK-Positive Lung Cancer?

ALK-positive lung cancer is a small subgroup of non-small-cell lung cancer (NSCLC) caused by a mutation in the ALK (anaplastic lymphoma kinase) gene. This mutation causes the gene to produce a faulty protein that promotes the growth and spread of cancer cells. ALK-positive lung cancer is usually adenocarcinoma, which starts in the mucous glands of the lungs.

Who Is at Risk for ALK-Positive Lung Cancer?

About 5% of people with NSCLC have an ALK rearrangement. Unlike other lung cancers, ALK-positive cancer tends to affect younger people, with about half of the cases diagnosed in people 50 or younger. It's also more common in people who have never smoked and isn't linked to other lung cancer risk factors like asbestos or air pollution. ALK-positive lung cancer is slightly more common in females or those assigned as females at birth.

Symptoms of ALK-Positive Lung Cancer

Lung cancer symptoms may not appear until the disease has spread to other parts of the body. Some common symptoms include:

Persistent cough
Chest pain that worsens with deep breathing, coughing, or laughing
Hoarseness
Unexplained weight loss and loss of appetite
Coughing up blood
Shortness of breath
Fatigue
Wheezing

When the cancer reaches stage IV, it may cause additional symptoms such as bone pain, neurological problems, and yellowing of the eyes or skin.

Diagnosing ALK-Positive Lung Cancer

If you have NSCLC, your doctor should test for the ALK genetic mutation to determine the best treatment plan. This involves taking a small sample of the tumor (biopsy) and sending it to a lab for analysis. Your doctor will also run imaging tests to see how far the cancer has spread.

Understanding ALK-Positive Lung Cancer: A Beginner's Guide

Treatment Options for ALK-Positive Lung Cancer

The main treatment for ALK-positive lung cancer is targeted therapy using ALK inhibitors (also called tyrosine kinase inhibitors or TKIs). These drugs block the abnormal ALK protein, preventing cancer cells from growing. Standard ALK inhibitors include alectinib (Alecensa) and brigatinib (Alunbrig). Other options are crizotinib (Xalkori), ceritinib (Zykadia), and lorlatinib (Lorbrena). Targeted therapy is often highly effective and has improved both survival and life quality.

ALK inhibitors are sometimes combined with chemotherapy, radiation, or surgery. If the cancer develops resistance to an ALK inhibitor, your doctor may prescribe a different one, increase the dose, or consider other treatments.

Potential Side Effects of ALK Inhibitors

Common side effects of ALK inhibitors include:

Diarrhea
Fatigue
Nausea
Vomiting
Blurry vision

In rare cases, some people may develop pneumonitis (lung inflammation) or heart problems.

Support and Palliative Care for ALK-Positive Lung Cancer

Dealing with a lung cancer diagnosis can be emotionally challenging. Support groups like the ALK Positive Group and the American Lung Association's online support community can help you connect with others who understand what you're going through. Your doctor can also refer you to individual or group therapy.

Palliative care is an essential part of cancer treatment, focusing on managing symptoms and side effects to improve your quality of life. This may include medications for pain and nausea, extra oxygen, or counseling. You can start palliative care at any point during your treatment. Talk to your healthcare team about incorporating palliative care into your plan.

Remember, you are the most important member of your healthcare team. Don't hesitate to ask questions, express concerns, or seek support when you need it. For more information on ALK-positive lung cancer, visit the American Cancer Society website.

The Bottom Line

Early genetic testing is crucial since targeted ALK inhibitors can provide years of disease control with fewer side effects than chemotherapy. The key is obtaining tissue or liquid biopsy samples for molecular analysis as soon as lung cancer is suspected. If you're experiencing persistent respiratory symptoms or have concerns about lung cancer risk, Doctronic can help connect you with appropriate screening and specialist care.