Lindsay Curtis is a health writer with over 20 years of experience in writing health, science & wellness-focused articles.
Lung cancer is the most common type of cancer in men and women around the world, with an estimated 228,820 new cases diagnosed in the U.S. each year. About 85% of lung cancer cases are caused by smoking. Smoking cannabis, air pollution, exposure to toxins (e.g., asbestos, radon) and second-hand smoke can also lead to lung cancer.
Symptoms of lung cancer may include cough, chest pain, fatigue, hoarse voice, trouble breathing, weight loss, and wheezing. Many individuals with lung cancer do not show any symptoms until the cancer has spread (metastasized) into other parts of the body.
Tumors located in the lungs can be detected through the use of imaging scans (e.g., chest X-rays, CT scan) and a diagnosis can be confirmed through a biopsy. Treatment options vary depending on the type and stage of the disease and may include chemotherapy, radiation, surgery, or a combination.
This article discusses the stages of cancer, the ways in which cancer progresses, where in the body it can spread, and what to expect throughout the process.
Visoot Uthairam / Getty Images
There are two main types of lung cancer: non-small cell lung cancer and small cell lung cancer. Once the type of lung cancer has been identified, healthcare providers will use imaging tests and biopsy results to determine how advanced the cancer is and if it has spread. This is known as staging.
Staging helps healthcare providers identify the most effective treatment options and your likely prognosis (outcome). The two most common types of cancer are staged and treated differently.
Small cell lung cancer (SCLC), also known as “oat cell cancer,” occurs in approximately 15% of cases. SCLC occurs most often in smokers. It is highly aggressive and spreads rapidly. Approximately 84% of people diagnosed with SCLC have metastatic disease when they are diagnosed. This means cancer has spread to other parts of the body.
SCLC is classified into two stages:
Non-small cell lung cancer (NSCLC) is the most common type of lung cancer.
The TNM system is used to stage non-small cell lung cancer, based on the following considerations:
There are five stages of NSCLC:
Lung cancer can spread when cancer cells break away from the original tumor and travel through the bloodstream or lymphatic system and form new tumors in other parts of the body. Lung cancer can spread to any part of the body, but the most common areas include the brain, bones, adrenal glands, liver, and lymph nodes.
If lung cancer spreads elsewhere, it is still referred to as lung cancer. For example, if it spread to the bones, it would be called lung cancer with bone metastases.
Lung cancer that has spread to the bone can cause severe pain and fractures. Approximately 30-40% of people with advanced lung cancer will develop lung cancer metastases to bones. Bones most commonly affected by metastases include the hands and feet, upper arm bone, thigh bone, pelvis, and spine.
Brain metastases—also called “brain mets”—occur when cancer cells in the lung break away, enter the bloodstream, and travel to the brain. This is very common in people with lung cancer. About 25% will have a brain met at the time of diagnosis, and up to 50% have a lifetime risk of developing the complication.
The liver is another common organ lung cancer cells affect. Up to 20% of people with small-cell lung cancer and 4% of patients with NSCLC will experience lung cancer metastatic to the liver. Lung cancer metastatic to the liver may cause abdominal pain and swelling, loss of appetite, and nausea. If the tumor blocks your bile ducts, you may develop jaundice.
The adrenal glands are small, triangle-shaped glands located on the top of each kidney. They are responsible for secreting hormones, including “stress hormones” (e.g., cortisol, adrenaline). Adrenal metastases occur in up to 40% of people with lung cancer, though it is present in less than 10% of patients at the time of diagnosis.
Lymph nodes are often the first area of the body where lung cancer cells are found if/when it spreads. Lymph nodes help filter out body waste and toxins. When lung cancer cells break away from the primary tumor location and travel through the lymphatic system, the cells are carried to lymph nodes.
If the spread of the cells is limited to lymph nodes close to the primary tumor, it is called “locally advanced.” If cancer cells have spread to lymph nodes further away from the primary tumor, it is considered metastatic.
If you’ve been diagnosed with lung cancer, chances are you are wondering about your prognosis. A prognosis is an estimate of how lung cancer will affect you and how the type/stage you have will respond to treatment.
Your healthcare provider may use the Lung Cancer Prognostic Index (LCPI) to determine your prognosis. This tool weighs several factors—including the stage and type of lung cancer, your medical history, smoking history, sex, and age—to make an estimated prognosis.
Lung cancer is most responsive to treatment when detected and treated early. It’s important to remember that survival rates and a prognosis are just your healthcare provider’s “best guess.” Nobody can tell you what will happen in your individual case, and your prognosis depends on many factors.
Lung cancer progression varies from person to person. There is no standard timeline for the progression of lung cancer, but knowing what to expect before, during, and after treatment can help you prepare for what lies ahead. Your healthcare team can help you make any lifestyle changes that will support your recovery and guide you in making treatment and health-related decisions.
Though no two people’s lung cancer journeys will be exactly alike, there are certain things you can expect:
Non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC) are the two main types of lung cancer. The staging and progression of these two types are different. Once the type of lung cancer has been identified, healthcare providers will use imaging tests and biopsy results to determine how advanced the cancer is and if it has spread (staging).
NSCLC progresses in five different stages (stages 0-5), and SCLC has two stages: limited and extensive. The stages depend on the size and location of the primary tumor, whether it has spread (metastasized), and what part(s) of the body it has spread to. Staging helps healthcare providers identify the most effective treatment options to improve your outcome.
Getting a diagnosis at an early stage before cancer has metastasized to other areas of the body can have a positive impact on your prognosis.
Living with lung cancer can be physically and emotionally draining, and may leave you with a lot of questions about how your cancer may progress and what the future holds. Knowing the type and stage of cancer you have can help you make an informed decision about the best treatment options for you. Advancements in lung cancer detection and treatment in recent years have led to significant improvements in lung cancer survival rates.
If lung cancer is progressing and/or spreading to other areas of the body, you may notice physical changes, depending on the area of the body where the cancer cells have metastasized. You may feel more fatigued, have a persistent cough, feel shortness of breath, feel nauseous, or experience pain in other parts of the body (e.g., abdomen).
Physical changes in end-stage lung cancer include fluid build-up around the lungs, shortness of breath, consistent cough, obstruction and/or bleeding of the airways, fatigue, weight loss and pain.
Lung cancer often progresses quickly, depending on the type of lung cancer diagnosed. Small cell lung cancer spreads more rapidly than non-small cell lung cancer. On average, lung cancers double in size in approximately four to five months.
Treatments such as chemotherapy, radiation, and surgery may stop the progression of lung cancer. Targeted therapies used to prevent tumors from growing can slow the progression of lung cancer. Thanks to advancements in diagnostic tools and treatments, survival rates for lung cancer have increased significantly in recent years.
Limiting processed foods and red meats can help ward off cancer risk. These recipes focus on antioxidant-rich foods to better protect you and your loved ones. Sign up and get your guide!
Thank you, {{form.email}}, for signing up.
There was an error. Please try again.
Merck Manual Professional Version. Lung carcinoma.
CancerConnect. Overview of lung cancer.
American Lung Association. Types of lung cancer.
American Lung Association. Key statistics for lung cancer.
American Lung Association. Lung cancer staging.
American Cancer Association. Non-small cell lung cancer stages.
National Cancer Institute. Non-small cell lung cancer treatment (PDQ®)- patient version.
Milovanovic IS, Stjepanovic M, Mitrovic D. Distribution patterns of the metastases of the lung carcinoma in relation to histological type of the primary tumor: an autopsy study. Ann Thorac Med. 2017;12(3):191–198. doi:10.4103/atm.ATM_276_16
Roato I. Bone metastases: when and how lung cancer interacts with bone. World J Clin Oncol. 2014;5(2):149-155. doi:10.5306/wjco.v5.i2.149
American Lung Association. Brain metastasis from lung cancer.
Ren Y, Dai C, Zheng H, et al. Prognostic effect of liver metastasis in lung cancer patients with distant metastasis. Oncotarget. 2016;7(33):53245-53253. doi:10.18632/oncotarget.10644
Ng TG, Damiris K, Trivedi U, George JC. Obstructive jaundice, a rare presentation of lung cancer: A case report. Respiratory Medicine Case Reports. 2021;33:101425.
MedlinePlus. Adrenal gland disorders.
Singh N, Madan K, Aggarwal AN, Das A. Symptomatic large bilateral adrenal metastases at presentation in small-cell lung cancer: a case report and review of the literature. J Thorac Dis. 2013;5(3):E83-E86. doi:10.3978/j.issn.2072-1439.2011.09.05
Cancer Research UK. Lung cancer.
Xia Y, Zhang B, Zhang H, Li W, Wang KP, Shen H. Evaluation of lymph node metastasis in lung cancer: who is the chief justice? J Thorac Dis. 2015;7(Suppl 4):S231-S237. doi:10.3978/j.issn.2072-1439.2015.11.63
Alexander M, Wolfe R, Ball D, et al. Lung cancer prognostic index: a risk score to predict overall survival after the diagnosis of non-small-cell lung cancer. Br J Cancer. 2017;117(5):744-751. doi:10.1038/bjc.2017.232
Canadian Cancer Society. Prognosis and survival for lung cancer.
American Lung Association. What to expect from your lung cancer journey.
Jones GS, Baldwin DR. Recent advances in the management of lung cancer. Clin Med (Lond). 2018;18(Suppl 2):s41-s46. doi:10.7861/clinmedicine.18-2-s41
Thank you, {{form.email}}, for signing up.
There was an error. Please try again.
Verywell Health uses cookies to enhance user experience and to analyze performance and traffic on our website. We also share information about your use of our site with our social media, advertising and analytics partners.