OVERVIEW

What is central lung cancer?

Lung cancer is a malignant tumor that occurs in the bronchi, bronchioles, and alveoli. Central lung cancer is a subtype of lung cancer that develops in the segmental bronchi and above^[1]. Early symptoms of this disease are not obvious, with typical symptoms including cough, hemoptysis, and shortness of breath.

The cause of this disease is unclear but may be related to smoking, diet, genetics, and certain lung diseases such as pulmonary inflammation and chronic obstructive pulmonary disease.

Treatment methods include surgery, radiotherapy, chemotherapy, targeted therapy, and immunotherapy. Early-stage central lung cancer patients have a better prognosis with timely treatment, while late-stage patients have a relatively poorer prognosis^[1]. If left untreated, the cancer may metastasize to the lungs, lymph nodes, liver, bones, brain, and other areas^[1].

Is central lung cancer common?

Yes. In 2020, there were approximately 2.2 million new cases of lung cancer worldwide^[2], with central lung cancer accounting for 60% to 70% of all lung cancer cases^[3]. This means roughly 1.32 to 1.54 million new cases of central lung cancer occurred globally in 2020.

SYMPTOMS

What are the manifestations of central lung cancer?

Symptoms of central lung cancer are not obvious in the early stages and are often detected in the middle or advanced stages^[4]. Typical symptoms include^[1]:

• Cough: This is the earliest symptom, usually presenting as an irritating dry cough with little or no phlegm.
• Hemoptysis or bloody sputum: Occasionally, blood streaks may appear in the coughed-up phlegm, or there may be persistent blood in the sputum. Severe cases can lead to massive hemoptysis.
• Shortness of breath or wheezing: Tumors growing inward may block the airways, or metastasis may compress lymph nodes, leading to symptoms such as difficulty breathing and gasping.
• Chest pain: Patients may experience dull pain in the chest.
• Fever: Intermittent low to moderate fever (37.3–39°C) is common, and high fever (39.1–41°C) may occur if infection is present.
• Weight loss: The tumor can cause loss of appetite, leading to significant weight loss.

What harm can central lung cancer cause?

Central lung cancer may lead to superior vena cava syndrome, difficulty swallowing, distant metastasis, etc.^[1].

1. Superior vena cava syndrome: Tumor invasion of the mediastinum may obstruct venous return, primarily manifesting as swelling of the face, neck, and upper limbs, as well as blurred vision, dizziness, and headaches.
2. Difficulty swallowing: Tumor invasion of the esophagus may cause patients to experience difficulty swallowing or a choking sensation while eating.
3. Distant metastasis:
   • Bone metastasis may cause bone pain and tenderness.
   • Liver metastasis may lead to pain in the liver area.
   • Brain metastasis may result in dizziness, headaches, nausea, vomiting, unsteady gait, speech disorders, and other symptoms.

CAUSES

What are the common causes of central lung cancer?

The exact etiology of central lung cancer remains unclear, but possible causes include^[1]:

• Smoking: The most common cause. Longer smoking duration and higher daily cigarette consumption significantly increase the risk. Passive smoking (e.g., secondhand smoke) is also a contributing factor.
• Occupational exposure: Contact with radon (released from soil, rocks, or building materials) or asbestos (a heat-resistant mineral fiber) in homes or workplaces may lead to this disease.
• Ionizing radiation: Prolonged exposure to radiation (e.g., X-rays, α-rays) elevates the risk of central lung cancer.
• Air pollution: Carcinogens from vehicle exhaust, industrial emissions, or incomplete combustion of fuels (e.g., coal releasing carbon monoxide) can trigger the disease.
• Genetics: Central lung cancer has genetic links. Mutations in oncogenes like Myc or Sox are associated with higher susceptibility.
• Lung diseases: Conditions such as chronic obstructive pulmonary disease (COPD) may increase the likelihood of developing this cancer.

Who is more likely to develop central lung cancer?

• Smokers: Most patients have a smoking history; long-term smokers face higher risks than non-smokers.
• Individuals with a family history: Genetic predisposition may play a role.
• Those exposed to ionizing radiation: Occupational or prolonged exposure raises the risk.
• Residents of heavily polluted industrial areas: Industrial carcinogens in the air increase susceptibility.
• People with lung diseases: COPD patients, for example, may have an elevated risk.

DIAGNOSIS

What tests are needed to diagnose central lung cancer?

1. Imaging examinations:

   • X-ray: Can indicate the location of the tumor and the approximate extent of the lesion, as well as provide information on the narrowing of surrounding lumens and growth patterns^[5].
   • CT: Offers higher resolution and can detect small lung lesions^[1].
   • MRI: Can clarify the relationship between the tumor and the aorta, and determine whether the tumor has metastasized to the brain (including meningeal metastasis) or bones^[1].

2. Bone scintigraphy: Helps assess whether the cancer has metastasized to the bones^[1].

3. Positron emission tomography (PET): Can display the metabolic activity of the tumor and provide a comprehensive evaluation of the condition^[1].

4. Fiberoptic bronchoscopy: Can determine the pathological type of lung cancer through biopsy and identify the lesion's location, including the distance from the tumor to the bronchial opening, aiding in surgical planning^[4].

5. Genetic diagnosis: Detects the presence of gene deletions or activations, facilitating the selection of targeted drugs; evaluates PD-L1 (programmed death-ligand 1, which affects immune function) expression to guide immunotherapy choices^[1].

6. Sputum cytology: A non-invasive diagnostic method that directly identifies exfoliated cancer cells in sputum. Suspected cases require three or more consecutive tests^[1].

Which diseases are easily confused with central lung cancer?

Central lung cancer is easily confused with hilar lymph node tuberculosis.

Hilar lymph node tuberculosis: Both conditions present with cough and fever. Hilar lymph node tuberculosis typically occurs in children and shows a positive tuberculin test, whereas central lung cancer patients test negative^[1].

TREATMENT

Which department should I visit for central lung cancer?

Respiratory Medicine, Oncology, Thoracic Surgery.

How should central lung cancer be treated?

Treatment options for central lung cancer include surgery, radiotherapy, chemotherapy, targeted therapy, and immunotherapy. The appropriate treatment method should be selected based on the stage of the disease:

Surgical Treatment:

1. Lobectomy: Suitable for lesions located more than 1.5 cm from the bronchial opening^[4]. For tumors involving the main bronchial opening and pulmonary artery trunk, pneumonectomy or sleeve lobectomy should be chosen. Pneumonectomy results in the loss of one lung function, reduced postoperative quality of life, and significantly higher complications and mortality rates compared to lobectomy.
2. Sleeve Resection: Suitable for central lung cancer invading the opening of the lobar bronchus without involvement of other organs. The procedure involves removing the affected lobe and corresponding bronchus in a sleeve-like fashion, preserving unaffected lung tissue and reducing surgical scope. Complications are significantly lower than with pneumonectomy^[6].

Drug Therapy: Mainly includes chemotherapy and targeted therapy

1. Chemotherapy Drugs: Commonly used drugs include albumin-bound paclitaxel, pemetrexed, paclitaxel, docetaxel, cisplatin, carboplatin, and nedaplatin. The choice depends on the patient's disease stage, pathological type, and physical condition. Chemotherapy may cause adverse effects such as kidney toxicity, nausea, vomiting, and tinnitus^[1].
2. Targeted Drugs: Commonly used drugs include osimertinib, aumolertinib, gefitinib, erlotinib, and icotinib, which can inhibit tumor growth. Specific target populations should be selected based on genetic mutations. Adverse effects may include constipation, edema, rash, liver dysfunction, and diarrhea^[1].

Radiotherapy:
It is usually combined with chemotherapy and selected based on the stage of central lung cancer and the patient's condition. Radiotherapy may cause side effects such as leukopenia and radiation pneumonitis. It is contraindicated for patients with poor general condition or severe heart, lung, or kidney dysfunction. Some patients may achieve complete remission after systemic chemotherapy, but the risk of brain metastasis remains high^[1].

DIET & LIFESTYLE

What should patients with central lung cancer pay attention to in their diet?

Since central lung cancer is a malignant tumor, patients may experience reduced appetite and weight loss in later stages. It is advisable to consume easily digestible and absorbable high-protein foods, such as noodles, dumplings, eggs, and milk.

What should patients with central lung cancer pay attention to in daily life?

Engaging in reasonable and moderate daily physical exercise can help reduce the risk of central lung cancer^[2].

PREVENTION

Can Central Lung Cancer Be Prevented? How to Prevent It?

The exact cause of central lung cancer is unclear, so there are no specific preventive measures. However, certain potential risk factors can be avoided in daily life and work to reduce the likelihood of developing the disease.

• Since smoking and secondhand smoke may contribute to central lung cancer, individuals should avoid smoking, stay away from secondhand smoke, and quit smoking early—these are the most effective ways to prevent the disease. Heavy smokers over 40 are advised to undergo regular check-ups^[1].
• When in environments containing carcinogens like asbestos or radon, wear masks to minimize exposure.
• Since ionizing radiation may trigger the disease, proper protective gear, such as radiation-proof clothing, should be worn when exposed to radiation.
• Since air pollution may contribute to the disease, wearing specialized protective masks outdoors can reduce the inhalation of pollutants.
• Given that central lung cancer may have a genetic component, individuals with a family history should proactively undergo lung screenings for early detection and treatment.
• Existing lung conditions should be actively treated to prevent progression to central lung cancer.