Cancer Lung Cancer Non-Small Cell What Is Stage 0 Non-Small Cell Lung Cancer? By Lynne Eldridge, MD Lynne Eldridge, MD Facebook Lynne Eldrige, MD, is a lung cancer physician, patient advocate, and award-winning author of "Avoiding Cancer One Day at a Time." Learn about our editorial process Updated on June 22, 2021 Medically reviewed Verywell Health articles are reviewed by board-certified physicians and healthcare professionals. These medical reviewers confirm the content is thorough and accurate, reflecting the latest evidence-based research. Content is reviewed before publication and upon substantial updates. Learn more. by Doru Paul, MD Medically reviewed by Doru Paul, MD Doru Paul, MD, is triple board-certified in medical oncology, hematology, and internal medicine. He is an associate professor of clinical medicine at Weill Cornell Medical College and attending physician in the Department of Hematology and Oncology at the New York Presbyterian Weill Cornell Medical Center. Learn about our Medical Expert Board Print Table of Contents View All Table of Contents Staging Symptoms Diagnosis Treatment Prognosis Coping Stage 0 non-small cell lung cancer (NSCLC), also known as carcinoma in situ, is the earliest stage at which lung cancer can be detected. It is limited to a single, small, non-invasive growth in the lung. In most cases, stage 0 lung cancer should be curable, typically with surgical removal or laser therapy. That said, even NSCLC in this early stage is a risk factor for developing a second primary cancer. 2:57 An Overview of Staging For Non-Small Cell Lung Cancer Staging Lung cancer is classified by stages that indicate its severity. Stage 0 NSCLC is defined as a tumor that's present in only a few layers of cells and has not grown beyond the basement membrane, which is the inner lining of the lung tissue. In contrast, stages 1 to 4 lung cancers have extended beyond this lining and are considered invasive. The TNM system is used to further define the stages of lung cancer, with T representing tumor size, N indicating the number of lymph nodes infiltrated by cancer, and M describing the extent of metastasis (spread of the cancer to other parts of the lungs or distant regions in the body). According to the TNM system, stage 0 lung cancer is defined as Tis, N0, M0. This means the tumor is in situ—that is, it has not spread to any lymph nodes or distant regions of the body. There are three main types of NSCLC, and they differ based on their cell structure: Adenocarcinoma, the most common type of NSCLC Squamous cell carcinoma Large cell carcinoma Any of these can be detected at stage 0. How Non-Small Cell Lung Cancer Is Diagnosed Morsa Images / Getty Images Stage 0 Lung Cancer Symptoms Although stage 0 NSCLC is detectable, it is rarely found because it is so small and usually doesn't cause symptoms that prompt an evaluation. If you have any respiratory symptoms, such as a persistent cough, shortness of breath, or chest pain, stage 0 NSCLC is not likely the cause. You could have another condition, like pneumonia or asthma, that your healthcare providers will try to identify. Diagnosis If NSCLC is caught in stage 0, it may be an incidental finding noted on diagnostic testing that's done for some other reason. Often, lung cancer is confirmed with a biopsy procedure in which a sample of the tissue is removed and examined under a microscope. Very small tumors like stage 0 NSCLC are typically assessed and completely removed in one procedure. An Overview of Lung Cancer Stages Screening Lung cancer has a better prognosis when it's detected and treated at an early stage. The U.S. Preventive Services Task Force (USPSTF) recommends a yearly computerized tomography (CT) scan of the chest to screen for lung cancer in people who: Are between 50 and 80 Have a 20 pack-year (or more) smoking history Currently smoke or have quit within the last 15 years Are healthy enough overall to withstand and benefit from treatment should lung cancer be diagnosed This applies whether or not symptoms are present. The USPSTF also advises that yearly screening can be stopped for most people after they've been smoke-free for 15 years or more. Treatment Regardless of the type of lung cancer, the treatment of choice for a stage 0 case is surgery. The goal is complete removal of the tumor. Radiation and chemotherapy are not usually part of the treatment, though stereotactic body radiotherapy (SBRT) may be considered if surgery isn't an option due to, say, the location of the tumor. Surgery Usually, a minimally invasive procedure or a wedge resection (removing a small wedge-shaped area of the lung) can be successful for stage 0 NSCLC. This saves the patient from having to undergo a major procedure. A pathologist examines a frozen section of the cancer tissue under a microscope as the surgery is in progress. They are looking for a margin of healthy lung tissue surrounding the cancerous area—an assurance that all of the cancer cells have been removed. If this is not present, additional tissue will be removed. Your Lung Cancer Pathology Report Prognosis If it is completely removed, stage 0 NSCLC is curable and should not recur. Generally, the TNM staging system is considered the most reliable way of determining the prognosis of lung cancer. Other indicators include certain antibodies, enzymes, and genes identified in biopsy samples. These immunohistochemical markers correlate with the TNM prognosis but are not as well established. Subsequent Cancer Risk Having had stage 0 NSCLC is a risk factor for developing another primary cancer. This means that even after recovering, you could be at risk of developing a new, unrelated cancer in your lung or any part of your body. The increased risk is believed to be due to some of the same risk factors that caused your stage 0 NSCLC to develop in the first place—usually, smoking. The prognosis of any subsequent primary cancer depends on its type and stage. If you've been treated for stage 0 lung cancer, your healthcare provider may continue to monitor your health for signs of a new primary cancer. This may include periodic X-rays or CT scans of your lungs, especially if you continue to smoke. Coping After being treated for stage 0 NSCLC, you shouldn't have any physical limitations once you recover. Nevertheless, it is vital that you look at your lifestyle to see if you can make any changes to reduce your risk of developing cancer again. Cancer prevention tips focused on preventing lung cancer include: Quitting smoking Reviewing and protecting yourself from any environmental exposures that might increase your risk of lung cancer (including those at work) Testing your home for radon and correcting a problem if it's detected Eating a healthy diet Getting regular exercise You might also consider joining a support group so you can receive and provide tips, strategies, and news about NCSLC. A Word From Verywell Stage 0 non-small cell lung cancer is the earliest stage of the disease. Though the cells are clearly defined as cancer cells, they can't spread if they are removed while the tumor is still in situ. Prompt treatment is important, and follow-up surveillance is a necessary part of your long-term health maintenance. 11 Sources Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. American Society of Clinical Oncology. Cancer - non-small cell: stages. National Cancer Institute. Non-small cell lung cancer treatment (PDQ®)–health professional version. American Cancer Society. Signs and symptoms of lung cancer. U.S. Preventive Services Task Force. Screening for lung cancer: US Preventive Services Task Force recommendation statement. JAMA. 2021;325(10):962–970. doi:10.1001/jama.2021.1117 Beaty BT, Weiner AA. Alternatives to surgery for early-stage non-small cell lung cancer: Stereotactic radiotherapy. Clin Chest Med. 2020;41(2):185-195. doi:10.1016/j.ccm.2020.02.001 American Cancer Society. Treatment choices for non-small cell lung cancer, by stage. Takahashi Y, Kuroda H, Oya Y, et al. Challenges for real-time intraoperative diagnosis of high risk histology in lung adenocarcinoma: A necessity for sublobar resection. Thorac Cancer. 2019;10(8):1663-1668. doi:10.1111/1759-7714.13133 American Cancer Society. Treatment choices for non-small cell lung cancer, by stage. Puderecki M, Szumiło J, Marzec-Kotarska B. Novel prognostic molecular markers in lung cancer. Oncol Lett. 2020;20(1):9-18.doi:10.3892/ol.2020.11541 Zhou H, Shen J, Zhang Y, et al. Risk of second primary malignancy after non-small cell lung cancer: a competing risk nomogram based on the SEER database. Ann Transl Med. 2019;7(18):439.doi:10.21037/atm.2019.09.01 American Cancer Society. Can lung cancer be prevented? By Lynne Eldridge, MD Lynne Eldrige, MD, is a lung cancer physician, patient advocate, and award-winning author of "Avoiding Cancer One Day at a Time." See Our Editorial Process Meet Our Medical Expert Board Share Feedback Was this page helpful? Thanks for your feedback! What is your feedback? Other Helpful Report an Error Submit