Lung Cancer: Symptoms, Diagnosis, Types and Treatment Options

What Is Lung Cancer?

Lung cancer develops when abnormal cells in the lungs begin growing uncontrollably.

These cells can form a tumor, invade nearby tissues and, in some cases, spread to other parts of the body.

Smoking is the leading cause of lung cancer, but people who have never smoked can also develop the disease.

Because early lung cancer may not cause noticeable symptoms, some cases are discovered only after the disease has progressed.

What Are the Main Types of Lung Cancer?

Lung cancer is divided into two main groups.

Non-Small Cell Lung Cancer

Non-small cell lung cancer, or NSCLC, is the most common type.

It includes several subtypes, such as:

• Adenocarcinoma
• Squamous cell carcinoma
• Large cell carcinoma

Treatment depends heavily on the stage of the cancer and the molecular characteristics of the tumor.

Small Cell Lung Cancer

Small cell lung cancer, or SCLC, is less common but usually grows and spreads more rapidly.

It is strongly associated with smoking.

Because it often spreads early, treatment commonly involves chemotherapy and radiotherapy rather than surgery.

What Are the Symptoms of Lung Cancer?

Symptoms can vary depending on the location and stage of the tumor.

Possible signs include:

• A cough that does not go away or becomes worse
• Coughing up blood
• Shortness of breath
• Chest pain
• Hoarseness
• Unexplained weight loss
• Loss of appetite
• Persistent tiredness or weakness
• Repeated chest infections such as pneumonia or bronchitis
• New wheezing

Many of these symptoms can also be caused by conditions that are not cancer.

However, a persistent or unexplained change should be evaluated by a doctor.

Can Lung Cancer Be Found Before Symptoms Appear?

Yes.

Low-dose CT screening can detect some lung cancers before symptoms develop in people who are considered at high risk.

Screening is generally aimed at adults with a significant smoking history who meet specific age and health criteria.

It is different from a normal chest X-ray and should be discussed with a healthcare professional to determine whether screening is appropriate.

How Is Lung Cancer Diagnosed?

If lung cancer is suspected, the evaluation may include several tests.

These can include:

• Chest X-ray
• CT scan
• PET scan in selected cases
• Bronchoscopy
• Needle biopsy
• Endobronchial ultrasound
• Laboratory examination of tissue samples

Imaging can identify a suspicious mass and help determine whether cancer may have spread.

However, the diagnosis itself is usually confirmed by examining cancer cells from a biopsy or another tissue sample.

Why Is a Biopsy Important?

A biopsy confirms whether a suspicious lung lesion is cancerous and identifies the exact type.

For many patients with non-small cell lung cancer, the tissue may also be tested for specific genetic or molecular changes.

These tests can help determine whether targeted medicines or certain immunotherapies may be suitable.

This is why obtaining enough tissue for detailed analysis can be an important part of modern lung cancer diagnosis.

How Is Lung Cancer Staged?

Staging describes how far the cancer has spread.

Doctors evaluate:

• Size and location of the main tumor
• Nearby lymph nodes
• Whether cancer has spread to the other lung
• Whether distant organs are involved

CT, PET, MRI and biopsies of lymph nodes or other areas may be used during staging.

The stage has a major influence on treatment decisions.

Surgery

Surgery may be an option for some patients with early-stage non-small cell lung cancer when the tumor can be completely removed and the patient is healthy enough for an operation.

Depending on the location and size of the tumor, surgery may involve removing:

• A small portion of lung
• One lobe of the lung
• An entire lung in selected cases

Nearby lymph nodes are often examined as well.

Surgery is used much less frequently for small cell lung cancer because the disease often spreads before diagnosis.

Radiotherapy

Radiotherapy uses high-energy radiation to destroy cancer cells.

It may be used:

• As a main treatment when surgery is not suitable
• After surgery in selected patients
• Together with chemotherapy
• To treat cancer that has spread
• To relieve symptoms such as pain or bleeding

Modern radiotherapy techniques aim to target the tumor while reducing exposure to healthy lung tissue and nearby organs.

Chemotherapy

Chemotherapy uses medicines that travel through the bloodstream and attack rapidly dividing cancer cells.

It may be given before or after surgery for certain cases of NSCLC.

Chemotherapy is also an important part of treatment for advanced non-small cell lung cancer and is commonly used for small cell lung cancer.

Targeted Therapy

Some non-small cell lung cancers contain genetic changes that encourage cancer cells to grow.

Targeted medicines can block specific abnormal proteins or pathways associated with these changes.

For this reason, molecular testing may be performed for changes involving genes such as EGFR, ALK, ROS1 and others.

The results can significantly influence treatment selection.

Immunotherapy

Immunotherapy helps the immune system recognize and attack cancer cells.

It has become an important treatment option for many patients with advanced lung cancer.

Doctors may test the tumor for markers such as PD-L1 and consider this together with other clinical and molecular information.

Immunotherapy may be given alone or combined with chemotherapy depending on the individual case.

Treatment for Small Cell Lung Cancer

Small cell lung cancer is generally treated differently from NSCLC.

Because it tends to grow and spread rapidly, chemotherapy is commonly the main treatment.

Radiotherapy may be added, particularly when the disease is limited to the chest.

Immunotherapy may also be incorporated into treatment for certain patients.

What Happens After Treatment?

Patients require regular follow-up after treatment.

This may include:

• Physical examinations
• CT scans
• Blood tests
• Monitoring of treatment side effects
• Evaluation for signs that the cancer has returned
• Support for breathing, nutrition and physical recovery

Stopping smoking is strongly recommended even after a lung cancer diagnosis because it may improve overall health and reduce the risk of treatment complications and additional cancers.

Living With Lung Cancer

Lung cancer is not one single disease.

A small early-stage tumor may be treated very differently from advanced cancer, and two patients with the same stage may receive different medicines because of differences in tumor genetics.

Modern lung cancer care therefore depends on accurate diagnosis, staging and molecular testing.

Patients are often best managed by a multidisciplinary team that may include thoracic surgeons, medical oncologists, radiation oncologists, pulmonologists, radiologists and pathologists.

The goal is to build an individualized treatment plan based on the exact type of lung cancer, its stage, the tumor's molecular characteristics and the patient's overall health.