Lung Cancer

Overview

Lung cancer is a disease in which abnormal cells grow in the lungs and can form a tumor. The lungs are the organs that help the body take in oxygen and remove carbon dioxide. Lung cancer can start in different parts of the lung and may behave differently depending on the type of cells involved.

There are two main groups of lung cancer: non-small cell lung cancer and small cell lung cancer. These categories help doctors understand how the cancer is likely to grow and which treatments may be most appropriate. Some lung cancers are found after symptoms appear, while others are detected during imaging tests done for another reason or through screening in people at higher risk.

A diagnosis of lung cancer can feel overwhelming, but modern cancer care uses many tools to evaluate the disease and plan treatment. Care is often provided by a multidisciplinary team, which may include specialists in oncology, lung diseases, surgery, radiology, pathology, and supportive care.

Symptoms

Lung cancer may not cause symptoms in its early stages. When symptoms do occur, they can vary from person to person and may be similar to symptoms of other lung or heart conditions. Common symptoms can include:

• A cough that does not go away or becomes worse over time
• Coughing up blood or rust-colored phlegm
• Shortness of breath
• Chest pain or discomfort, especially with deep breathing or coughing
• Hoarseness or changes in the voice
• Repeated chest infections
• Unexplained weight loss or loss of appetite
• Unusual tiredness or weakness
• Wheezing
• Pain in the shoulder, back, or bones

These symptoms do not always mean cancer is present. However, persistent or unexplained symptoms should be assessed by a healthcare professional.

Causes and Risk Factors

Lung cancer develops when changes occur in the DNA of lung cells, causing them to grow and divide in an uncontrolled way. In many cases, these changes are linked to exposure to harmful substances over time, but lung cancer can also occur in people with no obvious risk factor.

The most well-known risk factor is tobacco smoke, including cigarette, cigar, and pipe smoke. Exposure to secondhand smoke can also increase risk. Other risk factors may include:

• Long-term exposure to radon gas
• Exposure to asbestos, certain chemicals, or workplace dusts
• Air pollution
• A personal history of lung disease or previous cancer treatment to the chest
• A family history of lung cancer
• Increasing age

Having one or more risk factors does not mean a person will develop lung cancer, and some people diagnosed with lung cancer have never smoked. Risk assessment is best discussed with a doctor, especially for people with a history of smoking or other significant exposures.

Diagnosis

If lung cancer is suspected, doctors use several tests to understand what is happening in the lungs and, if cancer is present, to determine its type and extent. The diagnostic process may begin with a physical examination, a review of medical history, and questions about symptoms and risk factors.

Imaging tests are commonly used to look for abnormal areas in the lungs or chest. These may include chest X-rays, computed tomography scans, and other advanced imaging when needed. Imaging can show the size and location of a suspicious area, but it cannot confirm cancer by itself.

A tissue sample, called a biopsy, is usually needed to confirm the diagnosis. This sample is examined by a pathologist to identify the type of cells. Depending on the location of the abnormal area, the sample may be collected through a breathing tube examination, a needle procedure guided by imaging, or another method.

Additional tests may be performed to determine whether the cancer has spread and to identify specific features of the tumor. This information helps the medical team plan treatment in a more personalized way.

Treatment Options

Treatment for lung cancer depends on several factors, including the type of lung cancer, its stage, the person’s general health, lung function, and the molecular features of the tumor. The goal may be to remove or control the cancer, relieve symptoms, slow progression, or improve quality of life.

Common treatment options include surgery, radiation therapy, systemic treatments, and supportive care. Surgery may be considered when the cancer is localized and the person is well enough for an operation. Radiation therapy uses targeted energy to treat cancer cells in a specific area and may be used alone or with other treatments.

Systemic treatments travel through the body and may be used when cancer has spread or when additional treatment is needed before or after local therapy. These may include chemotherapy, immunotherapy, targeted therapy, or combinations of treatments, depending on the cancer’s characteristics.

Supportive and palliative care are important parts of lung cancer care at any stage. They focus on managing symptoms such as breathlessness, pain, fatigue, anxiety, and nutritional difficulties. Supportive care can be provided alongside cancer-directed treatment.

Because lung cancer treatment can be complex, decisions are usually made after careful evaluation by a specialist team. Patients are encouraged to ask questions, understand the goals and possible side effects of each option, and involve trusted family members or caregivers in discussions if they wish.

When to See a Doctor

A doctor should be consulted if symptoms such as a persistent cough, coughing up blood, unexplained shortness of breath, chest pain, repeated lung infections, or unexplained weight loss occur. Prompt medical evaluation is especially important for people with a history of smoking or exposure to known lung cancer risk factors.

People who are at higher risk may also wish to discuss lung cancer screening with a healthcare professional. Screening is not suitable for everyone, and eligibility depends on individual risk factors and overall health.

Seek urgent medical attention if there is severe breathing difficulty, significant chest pain, sudden confusion, fainting, or coughing up a large amount of blood. Early assessment can help identify the cause of symptoms and guide appropriate care.