Stage 4 Lung Cancer

What Is Stage 4 Lung Cancer?

Stage 4 lung cancer is the stage when cancer in the lungs has spread to other areas of the body, a process known as metastasis. Stage 4 lung cancer is also referred to as metastatic NSCLC. Stage 4 lung cancer is divided into two sub-stages; IVA and IVB. [¹]

Lung cancer in stage 4 affects both lungs and also spreads to the fluid surrounding the heart and lungs. Lung cancer spreads to distant organs of the body via the bloodstream. Stage 4 is the final stage of lung cancer, as once the cancerous cells enter the bloodstream, they can spread to any part of the body.

Non-small cell lung cancer is likely to spread to the liver, bones, brain, and adrenal glands. It is quite difficult to remove lung cancer from surgery when it reaches stage 4 since cancer has spread to the lymph nodes and vital organs of the body, like large blood vessels and the heart.

In this stage of cancer, doctors consider if other treatment options are possible, but if a patient is eligible for surgery and has a good response, surgery along with radiation therapy is performed to eliminate remaining cancer sites. [²]

What Are the Subtypes of Stage 4 Lung Cancer?

Stage 4 lung non-small cell lung cancer is divided into two sub-stages;

Stage IVA: This sub-stage can include;

Cancer in both lungs.
Cancer in the lung covering, called pleura, or the heart covering, called the pericardium.
Cancer has spread to the fluid which surrounds the lungs and heart.

Stage IVB: This sub-stage means that lung cancer has affected several areas of more than one organ.

The sub-stages define how big the cancer is and what is the extent of metastasis. Properly diagnosing the sub-stage of advanced lung cancer helps doctors determine the appropriate treatment for a patient. Stage 4 lung cancer is difficult to treat as the cancer has progressed into metastatic or advanced lung cancer. Currently, there is no cure for lung cancer, but certain treatment options help doctors control the disease and reduce the symptoms, to improve the quality of life of the patient. [³]

Stage 4 Lung Cancer Staging and Diagnosis

Stage 4 Lung Cancer Staging

In general, the TNM system is used to describe and classify cancers, including lung cancer, where:

T (tumor) describes the size and location of the tumor
N (nodes) indicates whether or not it has spread to nearby lymph nodes
M (metastasis) describes if and how far cancer has spread from its origin

How Common Is Stage 4 Lung Cancer?

The general trends in the appearance of lung cancer are affected by gender differences. Men are more likely to be diagnosed with lung cancer.

Lung cancer is the second most prevalent cancer in women, and the five-year survival rate is higher in women than in men.

How Is Stage 4 Lung Cancer Diagnosed?

Several tests and procedures are used to scan for stage 4 lung cancer. It is an advanced stage, which is diagnosed using the following procedures. [⁵]

MRI

Magnetic resonance imaging tests are used to create detailed images of areas inside the body to determine whether cancer has spread to a vital organ like the brain or spinal cord.

PET Scans

Positron emission tomography scans show the location of cancer cells in a body. A radioactive sugar injected into the patient’s body is taken up by cancerous cells, which gives away their location.

CT Scans

Computed tomography scans also show images of the inside of the body, just like an MRI. CT scans are used to monitor whether the lung cancer has affected lymph nodes and distant organs like the liver, brain, and adrenal glands.

Biopsy

Biopsies are used to confirm the diagnosis of lung cancer. In a biopsy, a sample of tissues is removed from the body and then sent to a laboratory for microscopic examination.

Stage 4 Lung Cancer Symptoms

The symptoms of advanced-stage lung cancer are;

A persistent cough that worsens with time
Coughing up blood
The appearance of blood in spit
Chest pain that worsens with laughing or breathing deeply
Wheezing
Weight loss
Fatigue
Frequent pneumonia and bronchitis.

Since cancer in stage 4 may have reached distant organs in the body, other symptoms include;

If cancer spreads to the brain: Headaches, dizziness, and seizures.
If cancer spreads to bones: Pain in the back and hips.
If cancer has reached the liver: Jaundice.

Stage 4 Lung Cancer Treatment

By the time stage 4 lung cancer is diagnosed, it has already progressed. Treatment for stage 4 lung cancer is very difficult, and often surgery and chemotherapy are not possible to treat the patient.

Stage IVA NSCLC has only spread to one distant organ, like the brain, which means that surgery might be possible. The surgery to remove the tumor is followed by chemotherapy or radiation therapy to support the treatment.

Stage IVB lung cancer is widely spread into distant organs, so targeted therapy drugs are sometimes the preferred choice of treatment.

Stage 4 Lung Cancer First-Line Treatment

The treatment for stage 4 lung cancer focuses on relieving the symptoms and stopping the disease progression.

The first line of treatment options include:

Surgery

When cancer has spread to only one distant site, surgery and radiation therapy target cancer, the course begins with focusing on the brain, then the lungs, combined with chemotherapy and radiation.

Cancer at stage 4 is too widespread, which means that other therapies like targeted drug therapy are also chosen as first-line treatment.

Targeted Therapy Drugs

The targeted therapy drugs are focused on gene mutations.

If cancer has a KRAS G12C gene mutation, then a KRAS inhibitor like sotorasib and adagrasib is used.
If the tumor has an ALK gene mutation, then an ALK inhibitor is used.
If cancer has changed in the EGFR gene, then suitable targeted drugs are used. [⁶]

Can Stage 4 Lung Cancer Be Cured?

Stage 4 lung cancer currently has no cure, but there are many treatment options available that can relieve the symptoms of the patient and improve their quality of life. Management of stage 4 lung cancer usually involves palliative chemotherapy and radiation therapy, sometimes along with surgery. [⁷]

Prognosis: Stage 4 Lung Cancer Survival Rate

Stage 4 Lung Cancer Survival Rate

The life expectancy of an individual having cancer is considered using the five-year relative survival rate. This rate includes the patients who are being treated for cancer and those who have successfully received treatment and show no further presence of the disease.

Stage 4 lung cancer, also known as metastatic NSCLC, has spread to distant organs of the body, which lowers the overall survival rate of the affected individuals.

The five-year survival rate of stage 4 non-small cell lung cancer patients is 9%, according to the American Cancer Society. [⁴]

Stage 4 Lung Cancer Recurrence Rate

The chances of recurrence in a stage 4 lung cancer patient are high since cancer has spread to many parts of the body, and even after surgery and chemotherapy, certain parts of the disease may remain behind and make a reappearance. [⁸]

Stage 4 Lung Cancer Growth Rate

Stage 4 lung cancer has a poor prognosis. Lung cancer is a rapidly spreading and aggressive form of cancer, which renders survival rates even lower for stage 4 patients.

Lifestyle Changes for Preventing and Managing Lung Cancer

Lung cancer is not preventable in most cases, but there are certain lifestyle modifications that can lower your chance of developing cancer in the lung in your lifetime.

Avoid consumption of tobacco: Don’t smoke and avoid breathing tobacco from other sources like other people’s smoke.
Eating a healthy diet: The antioxidants and vitamins in fruits and vegetables can reduce the risk of developing cancerous cells.
Limiting exposure to cancer-causing agents: Certain cancer-causing agents like radon in the workplace or home can increase the chances of developing lung cancer.

Conclusion

Takeaway

Stage 4 lung cancer is the most advanced stage of lung cancer. The cancer has spread from the lungs and affects vital organs of the body, which further complicates the symptoms and makes a patient’s health condition worse. Many people tend to ignore the early warning signs of lung cancer, which dramatically increases the number of patients who are diagnosed with stage 4 lung cancer.

It is important to detect any abnormal signs in your body and seek professional medical help as soon as possible to improve your survival rate and disease management.