Lung Adenocarcinoma Stage IV

Stage IV lung adenocarcinoma represents the most advanced form of this disease, where cancer has spread beyond the lungs to distant parts of the body. While this diagnosis brings significant challenges, advances in treatment options including targeted therapies and immunotherapy continue to improve outcomes for patients.

Table of contents

• What is Stage IV Lung Adenocarcinoma?
• Disease Identification
• Related Lung Cancers
• How Stage IV is Diagnosed
• Treatment Options
• Living with Stage IV Lung Adenocarcinoma

What is Stage IV Lung Adenocarcinoma?

Lung adenocarcinoma is the most common type of lung cancer in the United States, accounting for about 40% of all lung cancers^[5]. It is classified as a type of non-small cell lung cancer (NSCLC), which represents over 80% of all lung cancer cases^[1]. This cancer typically develops from the cells that produce mucus in the lungs and most often occurs in the outer regions of the lungs^[5].

Stage IV, also called stage 4, is the most advanced stage of lung adenocarcinoma. At this stage, the cancer has spread beyond both lungs to other parts of the body^[1]. Stage IV lung cancer is also referred to as metastatic or advanced lung cancer, meaning the cancer has moved from its original location to distant areas^[4].

Stage IV lung adenocarcinoma is divided into two substages. Stage 4A means the cancer may have spread to the other lung, the layers covering the lung or heart, fluid around the lung or heart, or a single distant area outside the chest such as the liver, bones, or brain^[4]. Stage 4B indicates the cancer has spread to multiple areas outside the chest, such as several distant organs or lymph nodes^[4].

Common sites where stage IV lung adenocarcinoma may spread include the adrenal glands, bones, both lungs, brain, and liver^[14]. Cancer cells can travel to these distant locations through the blood or lymph nodes^[14].

Disease Identification

metastatic lung adenocarcinoma, advanced lung adenocarcinoma

Related Lung Cancers

Lung adenocarcinoma is one of several types of non-small cell lung cancer. Related types include squamous cell carcinoma, which develops from flat cells lining the airways and is typically found in the central parts of the lungs, and large cell carcinoma, which can develop in any part of the lung and tends to grow and spread quickly^[1].

How Stage IV is Diagnosed

Diagnosis of stage IV lung adenocarcinoma typically involves several types of tests. Imaging tests create pictures of the body to show the location and size of the cancer^[9]. These may include X-rays, CT scans, MRI scans, and positron emission tomography (PET) scans^[9].

A biopsy, which involves removing a sample of tissue for testing in a laboratory, is necessary to confirm the diagnosis^[9]. Laboratory tests examine the removed tissue to determine if cancer cells are present and what type they are.

For patients diagnosed with stage IV disease, additional testing is performed to look for specific genetic changes or mutations in the cancer cells^[7]. These tests help doctors determine if targeted therapies might be effective treatment options. Common mutations tested include changes in the EGFR gene (epidermal growth factor receptor) and ALK gene^[7].

Treatment Options

The goal of treatment for stage IV lung adenocarcinoma is to control the cancer for as long as possible and help reduce symptoms^[4]. Treatment depends on what genetic changes are found in the cancer cells, where the cancer has spread, and the patient’s overall health^[4].

Targeted Therapy

Targeted therapy uses drugs that attack specific characteristics of cancer cells. If testing shows certain genetic mutations, targeted therapy may be offered instead of chemotherapy^[7]. For patients whose cancer cells have EGFR mutations, drugs called EGFR inhibitors such as erlotinib, gefitinib, or osimertinib may be used^[7]. These medications work by blocking signals that tell cancer cells to grow and divide.

For a specific type of EGFR mutation called exon 20 insertion mutation, the drug amivantamab may be offered if the cancer does not respond to or stops responding to chemotherapy^[7].

Chemotherapy

Chemotherapy uses powerful drugs to kill cancer cells. It may be offered for stage IV lung adenocarcinoma if no treatable genetic mutations are found^[7]. Common chemotherapy drug combinations include cisplatin or carboplatin with gemcitabine, or cisplatin and pemetrexed for non-squamous types of non-small cell lung cancer^[7].

Single chemotherapy drugs may be used if a patient is in poor health and cannot tolerate combination treatments^[7]. After completing chemotherapy, some patients may receive maintenance therapy with a drug called pemetrexed to help slow the return of cancer^[7].

Immunotherapy

Immunotherapy is a type of treatment that helps the patient’s own immune system fight cancer^[10]. These treatments work by blocking proteins that prevent the immune system from attacking cancer cells. Several immunotherapy drugs have been approved for treating stage IV lung adenocarcinoma, including atezolizumab, cemiplimab, and dostarlimab^[10].

Immunotherapy may be used alone or in combination with chemotherapy as a first-line treatment for advanced lung cancer^[10].

Radiation Therapy

Radiation therapy uses high-energy beams to kill cancer cells. For stage IV lung adenocarcinoma, radiation may be used to control symptoms and improve quality of life^[4]. Special types of radiation therapy, such as stereotactic radiosurgery (SRS), may be used to treat cancer that has spread to the brain^[6].

Palliative Care

Palliative therapies focus on providing comfort and improving quality of life for patients with stage IV lung cancer^[12]. These treatments can help relieve chest pain, address shortness of breath, remove blockages from airways, reduce fluid buildup in the lungs, and treat fluid accumulation around the heart^[12].

Living with Stage IV Lung Adenocarcinoma

Living with stage IV lung adenocarcinoma affects daily life in different ways depending on the stage and treatment being received^[17]. Many patients experience symptoms such as breathlessness, which is common in people with lung cancer^[17].

Managing Breathlessness

Breathlessness can often be improved with simple measures. These include breathing in slowly through the nose and out through the mouth, making daily activities easier by using helpful tools like a shopping trolley, using a fan to direct cool air toward the face, and eating smaller, more frequent meals^[17]. If these measures are not sufficient, medications or home oxygen therapy may help^[17].

Emotional Support

A cancer diagnosis can lead to a range of emotions including shock, anxiety, sadness, and depression^[17]. Being open and honest about feelings with family and friends can help^[17]. Many patients find it helpful to talk with a trained counselor, psychologist, or someone at a specialist phone helpline^[17].

Talking with others who have experienced lung cancer through local support groups can also be beneficial^[17]. Healthcare teams typically include a lung cancer specialist nurse who can provide support and information about other resources^[17].

Working with Your Healthcare Team

Open communication with doctors is increasingly important in managing stage IV lung adenocarcinoma. This approach, called shared decision-making, encourages two-way communication between patients and their healthcare teams^[12]. Acknowledging difficult emotions and addressing them can improve quality of life^[12].

Patients should discuss all treatment options with their doctors, including potential side effects, and ask about clinical trials, which are research studies testing new medications^[12].