Lung cancer

Disease Description (Causes and Symptoms)

• Definition summary: A disease in which abnormal cancer cells in the lungs proliferate uncontrollably to form a mass and, as the disease progresses, can metastasize throughout the body—including the bones, liver, adrenal glands, kidneys, brain, and spinal cord—via the lymph nodes and bloodstream. The main classifications are non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC).
• Causes / pathophysiology: Smoking is the most important risk factor (the risk of developing the disease is greatly increased compared with nonsmokers). Occupational carcinogens (such as asbestos and chromium), air pollution, previous lung disease, and genetic factors are also associated. The key pathophysiology involves abnormal proliferation of cancer cells, invasion of surrounding tissues, and metastasis through blood vessels and lymphatic vessels.
• Main symptoms: Often asymptomatic in the early stages. Cough (worsening chronic cough), hemoptysis (blood-streaked sputum), shortness of breath, chest pain, voice changes (vocal cord paralysis), and systemic symptoms (weight loss and fatigue).

Treatment Methods (Standard Treatment·Medications·Procedures/Surgery·Lifestyle Management and Precautions)

• Principles for selecting treatment: Treatment is determined according to the histologic type of cancer (SCLC vs NSCLC), stage (localized/regional/metastatic), the patient's general condition (physical fitness and lung function), and the results of molecular genetic testing.
• Non-small cell lung cancer (NSCLC)
  • Early stage (mainly I–II, some IIIa): Curative surgery (such as wedge resection·lobectomy·pneumonectomy) is the standard and may result in a cure. Adjuvant chemotherapy (anticancer drugs) may be recommended after surgery depending on the stage and prognosis.
  • Locally advanced (some III): Concurrent chemoradiotherapy or a combination of chemotherapy/radiotherapy before and after surgery.
  • Metastatic (IV) or inoperable: Molecular targeted therapy (for example, the corresponding targeted therapy when mutations in EGFR, ALK, ROS1, BRAF, MET, RET, etc. are positive), immune checkpoint inhibitors (PD‑1/PD‑L1 inhibitors) alone or in combination with chemotherapy, systemic chemotherapy (standard anticancer drugs), etc.
• Small cell lung cancer (SCLC)
  • Limited stage: Chemotherapy (the main treatment) combined with radiation therapy. Prophylactic cranial irradiation (PCI) may be considered when the treatment response is good.
  • Extensive stage: Systemic chemotherapy is the standard. The goal is symptom relief and prolongation of survival rather than cure.
• Radiation therapy: Used for local control (tumor reduction), pain relief, and as an adjunct to systemic treatment. It may be used with curative intent in some patients.
• Latest standard enhancements: Targeted therapy and immunotherapy are prioritized according to the results of molecular genetic testing (gene mutations and PD‑L1).
• Supportive care and lifestyle management: Smoking cessation (the most important preventive and treatment-supportive measure), preservation of lung function (pulmonary rehabilitation), nutritional management, infection prevention (consider vaccination), and management of pain and shortness of breath, along with psychosocial support.
• Precautions and complications: Acute and chronic treatment-related adverse effects (bone marrow suppression·infection, nausea·vomiting, fatigue, radiation pneumonitis, etc.), respiratory failure·bleeding·infection after surgery, and complications caused by the tumor itself (obstructive bronchitis, pneumothorax, and pain and neurological symptoms caused by metastasis). Lung function (spirometry and DLCO) should be assessed before and after treatment.

Checklist Before an Outpatient Visit (Items to Prepare and Example Questions)

• Items to bring (recommended)
  • A list of currently used medications (including prescriptions·OTC medications·health supplements)
  • A summary of allergies and previous surgeries and medical conditions
  • Smoking history (current status, years started·stopped, amount smoked per day → calculate pack‑years), alcohol use, and occupational history (exposure to hazardous substances)
  • Original or copied results and images from previous tests (chest X‑ray, CT, PET, MRI, biopsy·pathology reports, etc.) (if possible, imaging CDs)
  • A record of recent symptom changes (cough, hemoptysis, weight changes, etc.) and when weight loss·shortness of breath worsened
  • Whether oxygen is used and information about portable oxygen equipment (if used)
• Examples of questions to prepare for the outpatient visit (simple sentences that can be asked directly to the doctor)
  • “What is the first treatment recommended for my current stage?”
  • “Based on my test results (imaging/biopsy), is targeted therapy or immunotherapy possible?”

Examples of General Questions to Ask the Doctor

• What is the stage of this cancer and what does it mean (treatment goal: cure vs prolongation of survival/symptom relief)?
• What treatment options do you recommend for me, and what are the advantages, disadvantages, and expected adverse effects of each option?
• Is surgery possible, and what can I expect regarding functional recovery (breathing) after surgery?
• Have targeted gene tests (PCR/NGS) and PD‑L1 testing been performed, and what are the results?
• How will adverse effects such as pain·shortness of breath·vomiting be managed during treatment?
• Is participation in a clinical trial (new medication) possible, and are there any trials you would recommend?
• When might I be able to return to work during or after treatment, and what restrictions on daily activities should I expect?

Examples of Disease-Specific Questions (1–2)

• Were molecular marker tests such as EGFR/ALK/ROS1/PD‑L1 performed on the biopsy specimen? (The availability of targeted therapy·immunotherapy depends on the results.)
• Are my pulmonary function test results (FEV1, DLCO) at a level that would allow me to tolerate surgery? If surgery is not possible, what alternative treatment options are recommended?