Lung Cancer

Risk Factors

• Smoking: The principal risk factor. The risk increases with the duration and intensity of smoking; cessation significantly reduces risk.

• Occupational exposures: Asbestos, silica, diesel exhaust, and other inhaled carcinogens.

• Environmental exposures: Radon gas (less common in Australia compared to some other regions), passive smoking.

• Genetic predisposition: Family history of lung cancer may slightly increase risk.

• Other factors: Chronic lung disease (e.g. COPD) and poor general health.

Screening for Lung Cancer

Rationale for Screening

• Early detection can significantly improve survival, as curative treatments (surgery or combined chemoradiotherapy) are more effective in early‐stage disease.

• Low‐dose CT (LDCT) scanning has been shown internationally to reduce lung cancer mortality among high‐risk groups.

Current Australian Recommendations

• At present, targeted screening is recommended for individuals at high risk, typically defined as:

  • A significant smoking history (e.g. ≥30 pack‐years) and

  • Age range generally 50–70 years (exact upper age thresholds can vary by guideline)

  • A consideration of comorbidities and the ability to undergo potentially curative treatment.

• National lung cancer screening programme:

  • As of the publication dates mentioned, Australia is working towards/has recommended a staged rollout of a national screening program using LDCT in high‐risk individuals.

  • Specific details regarding frequency (usually annual LDCT) and precise eligibility criteria may evolve over time, so GPs should consult the most recent RACGP and government guidance.

Role of the GP in Screening

• Risk stratification: Identify patients at high risk based on smoking history and other factors.

• Offer smoking cessation support.

• Discuss benefits and harms of LDCT screening (e.g. false positives leading to unnecessary investigations or interventions).

• Ensure adequate follow‐up for abnormal screening results.

Clinical Presentation and Investigation

Signs and Symptoms

Common presenting features include:

• Persistent cough (often new or changed in a smoker/ex‐smoker)

• Haemoptysis

• Dyspnoea

• Chest pain (can be pleuritic or dull)

• Recurrent chest infections or pneumonia

• Unintentional weight loss, fatigue

• Hoarseness (recurrent laryngeal nerve involvement)

• Features of metastatic disease (e.g. bone pain, neurological symptoms)

Red Flag: Any smoker or ex‐smoker aged >40 years with a new, persistent or altered cough should be investigated further.

Initial Investigations in General Practice

• Chest X‐ray (CXR): First‐line imaging if lung cancer is suspected.

• CT chest: If CXR is abnormal or high suspicion remains despite a normal CXR, a contrast‐enhanced CT chest is warranted.

• Sputum cytology: Now less commonly used as a diagnostic tool, but might occasionally be done.

• Other relevant tests: Full blood count, renal function (especially prior to CT with contrast), liver function tests.

Referral for Specialist Assessment

• Urgent referral to a respiratory physician or specialist multidisciplinary team if imaging suggests lung cancer.

• If a suspicious mass is identified, further investigations to confirm pathology often involve bronchoscopy, endobronchial ultrasound‐guided biopsy (EBUS), or CT‐guided biopsy.

Staging and Pathology

Histological Types

• Non–small cell lung cancer (NSCLC)

  • Adenocarcinoma (most common histological subtype in Australia, especially in non‐smokers)

  • Squamous cell carcinoma

  • Large cell carcinoma

• Small cell lung cancer (SCLC)

Staging

• NSCLC uses the TNM (Tumour, Node, Metastasis) staging system, which guides treatment decisions.

• SCLC is often categorised as either limited (confined to one hemithorax, potentially treatable within a tolerable radiation field) or extensive (disease spread beyond one hemithorax).

Molecular Markers

• Testing for molecular alterations (e.g. EGFR mutation, ALK rearrangement, ROS1, PD‐L1 expression) is standard in NSCLC, guiding targeted therapies and immunotherapy decisions.

Management

Management of lung cancer should be delivered via a multidisciplinary team (MDT) approach involving respiratory physicians, oncologists, thoracic surgeons, radiologists, palliative care specialists, and GPs.

Non–Small Cell Lung Cancer

1. Surgical resection

   • Main curative option for early‐stage disease (stage I or II, and selected stage III).

   • Types: lobectomy, segmentectomy, pneumonectomy (depending on location, size, and patient fitness).

2. Radiotherapy

   • Curative radiotherapy (often combined with chemotherapy) for those with locally advanced disease who are not surgical candidates.

   • Stereotactic ablative radiotherapy (SABR) may be used for small, peripheral tumours in patients unfit for surgery.

3. Systemic therapies

   • Chemotherapy: Platinum‐based combinations are standard in many cases.

   • Targeted therapies: EGFR inhibitors (e.g. gefitinib, erlotinib), ALK inhibitors (e.g. crizotinib), etc.

   • Immunotherapy: Anti–PD‐L1 therapies (e.g. pembrolizumab, nivolumab) for advanced or metastatic disease depending on PD‐L1 expression and other factors.

4. Adjuvant therapy

   • Postoperative chemotherapy or chemo‐radiotherapy in resected stage II or III disease to improve survival.

5.2 Small Cell Lung Cancer

• Tends to be more aggressive but often more responsive to chemotherapy.

• Limited‐stage disease: combined chemotherapy and radiotherapy.

• Extensive‐stage disease: chemotherapy (with or without immunotherapy), palliative radiotherapy for symptom control.

Supportive and Palliative Care

Role of the GP

• Continuity of care: Ongoing review of symptoms, psychosocial support, care coordination.

• Management of comorbidities: Especially COPD, cardiovascular disease, diabetes, etc.

• Smoking cessation support: Even after diagnosis, quitting smoking can slow disease progression and improve outcomes.

• Nutritional support: Address weight loss, cachexia, nutritional deficits.

• Palliative care referral: Early introduction can improve quality of life, symptom control, and possibly outcomes.

Symptom Management

• Dyspnoea: Consider bronchodilators if coexisting COPD, opioids for severe breathlessness, oxygen therapy if indicated by hypoxaemia.

• Pain: WHO pain ladder approach, adjuvant therapies, radiotherapy for bone metastases.

• Psychological support: Referral to counselling services, psychology, or mental health services if required.

Prevention and Health Promotion

1. Smoking cessation

   • The single most effective intervention to reduce lung cancer risk.

   • Offer evidence‐based cessation support: nicotine replacement therapy (NRT), varenicline, bupropion, and counselling.

   • Reinforce prevention strategies in the community and among family members.

2. Occupational health measures

   • Advise on minimising exposure to carcinogenic substances (e.g. asbestos, silica).

   • Encourage use of protective equipment and regular workplace screening if relevant.

3. Air quality and other lung health measures

   • Awareness of environmental pollutants.

   • Appropriate vaccinations (e.g. influenza, pneumococcal in at‐risk groups) to maintain respiratory health.