Lung Cancers

Lung Cancers

Lung cancer is one of the leading causes of cancer-related deaths worldwide. It arises from abnormal growth of cells in the lungs and can spread early to lymph nodes, brain, bones, liver, and other organs. While smoking is the most common cause, lung cancer can also occur in non-smokers. Advances in molecular testing, targeted therapy, and immunotherapy have significantly improved outcomes.

Overview

Lung cancer develops when lung cells grow uncontrollably and form a tumor.

It is broadly divided into Non-Small Cell Lung Cancer (NSCLC) and Small Cell Lung Cancer (SCLC).

NSCLC accounts for nearly 80–85% of cases.

SCLC is less common but grows and spreads rapidly.

Treatment depends on cancer type, stage, molecular profile, and patient health.

Risk Factors

Non Modifiable

Increasing age, usually over 50 years

Male sex (though incidence in women is increasing)

Family history of lung cancer

Genetic susceptibility

Modifiable

Cigarette smoking

Second-hand smoke exposure

Occupational exposure to asbestos, silica, nickel, chromium

Radon gas exposure

Air pollution

Chronic lung diseases such as COPD or pulmonary fibrosis

Prevention Tips

Quit smoking and avoid second-hand smoke

Use protective equipment in high-risk occupations

Reduce exposure to indoor and outdoor air pollution

Maintain lung health with regular exercise

Low-dose CT screening for high-risk individuals

Symptoms

Early

Often no symptoms in early stages

Common

Persistent cough

Coughing up blood

Chest pain

Shortness of breath

Hoarseness of voice

Recurrent respiratory infections

Advanced

Unintentional weight loss

Fatigue

Bone pain

Headache or seizures due to brain spread

Swelling of face or neck

Diagnosis

Approach

Clinical Evaluation

Detailed medical and smoking history

Physical and respiratory examination

Tests

Blood tests for baseline assessment

Imaging

Chest X-ray

CT scan of chest and upper abdomen

PET-CT for staging

MRI brain in selected cases

Biopsy

Bronchoscopy-guided biopsy

CT-guided lung biopsy

Endobronchial ultrasound (EBUS) biopsy

Pleural fluid analysis if effusion present

Molecular Tests

EGFR mutation testing

ALK rearrangement testing

ROS1, BRAF, KRAS, MET, RET, NTRK mutations

PD-L1 expression testing

Staging

TNM staging system

Assessment of lymph node and distant organ involvement

Treatment

Principle

Surgery

Lobectomy or segmentectomy for early-stage disease

Pneumonectomy in selected cases

Lymph node dissection

Radiation Therapy

Adjuvant radiotherapy after surgery

Definitive radiotherapy when surgery is not possible

Stereotactic Body Radiation Therapy (SBRT)

Palliative radiotherapy

Systemic Therapy

Chemotherapy

Targeted therapy for mutation-positive cancers

Immunotherapy using checkpoint inhibitors

Chemo-immunotherapy combinations

Supportive Care

Management of breathlessness and cough

Pain control

Nutritional support

Pulmonary rehabilitation

Psychological and palliative care

Do's and Don'ts

Dos

Quit smoking immediately

Seek early medical evaluation for persistent respiratory symptoms

Follow treatment and follow-up schedules

Maintain nutrition and physical activity as tolerated

Report treatment side effects promptly

Donts

Do not ignore coughing up blood

Do not rely on alternative or unproven treatments

Avoid smoking and exposure to pollutants

Do not stop prescribed treatment without consulting doctors