OVERVIEW

What is peripheral lung cancer?

Peripheral lung cancer refers to lung cancer that occurs below the segmental bronchi and is a subtype of lung cancer. Since the primary lesion is located far from the hilum and is relatively localized, there are often no obvious symptoms in the early stages, and it is usually diagnosed at an advanced stage^[1-4].

Current treatment mainly involves comprehensive approaches such as surgery, chemotherapy, radiotherapy, targeted therapy, and immunotherapy.

Early-stage treatment is more effective and may lead to a cure; if treatment is delayed, distant metastasis may occur, which can be life-threatening^[1-4].

Which department should patients with peripheral lung cancer visit?

Oncology, Respiratory Medicine, Thoracic Surgery.

What are the common causes of peripheral lung cancer?

The pathogenesis of this disease is not yet clear, but it may be related to the following factors:

• Smoking: The most common cause of this disease. Harmful substances in tobacco can affect normal lung tissue cells, and the longer the duration of smoking, the higher the risk. Secondhand smoke also increases the likelihood of developing this disease.
• Occupational carcinogens: Long-term exposure to substances such as asbestos due to work conditions. These substances, when inhaled into the lungs, can disrupt normal cell growth, leading to lung cancer.
• Air pollution: Exhaust fumes from vehicles and industrial emissions may contain carcinogens. Inhaling these can interfere with normal cell growth, increasing the risk of this disease.
• Ionizing radiation: Long-term exposure to ionizing radiation can cause mutations in normal cells, increasing the likelihood of this disease.
• Genetic factors: Lung cancer patients show some familial clustering, suggesting that family members may share certain predisposing genes, increasing the risk.
• Diet: An unbalanced diet lacking vegetables and fruits can impair normal bodily functions and may also increase the risk of this disease^[1-4].

Is peripheral lung cancer common?

Yes. In 2020, there were approximately 2.2 million new cases of lung cancer worldwide, with about 1.8 million deaths. Peripheral lung cancer is a common type, accounting for about 30% of all lung cancer cases (approximately 3 out of 10 lung cancer patients have peripheral lung cancer)^[5,6].

What are the possible symptoms of peripheral lung cancer?

Early stages often show no symptoms, and most cases are discovered during chest X-rays or CT scans.
As the tumor progresses, symptoms such as coughing, bloody sputum, chest pain, fever, shortness of breath, and weight loss may appear.
In advanced stages, the tumor may compress or invade nearby organs, leading to symptoms like difficulty swallowing and hoarseness^[1-4].

What tests are needed for peripheral lung cancer?

Sputum cytology: Cancer cells shed from the tumor may be coughed up in sputum. Finding cancer cells in sputum can confirm the diagnosis.

• Chest X-ray: Shows tumors originating below the segmental bronchi. Early stages may appear as small localized shadows, nodules, spherical shadows, or mesh-like shadows. The mass may have spicules, notches, or lobulation. However, X-rays have limitations in detection, and further tests are needed.
• CT scan: Offers higher resolution than X-rays. Contrast-enhanced CT can also aid in clinical staging.
• MRI: Can clarify the relationship between the tumor and major blood vessels and is important for detecting distant metastases in the brain or spinal cord.
• Bronchoscopy: Improves the diagnostic rate of peripheral lung cancer and helps in planning surgical approaches^[1-4].
• Pathological examination: CT or ultrasound-guided percutaneous biopsy is the gold standard for diagnosis. Some patients may be diagnosed via lymph node biopsy or pleural effusion cytology.

How is peripheral lung cancer treated?

Depending on the condition, a combination of treatments may be required. Common methods include^[1-4]:

• Surgery: The best treatment for early-stage patients. The extent of resection depends on the lesion's location, size, the patient's overall health, and comorbidities.
• Chemotherapy: Common drugs include albumin-bound paclitaxel, docetaxel, cisplatin, and carboplatin. Side effects may include kidney toxicity, nausea, vomiting, tinnitus, and leukopenia.
• Targeted therapy: Common drugs include gefitinib, icotinib, crizotinib, and osimertinib. For patients with sensitive mutations, these drugs can inhibit tumor growth. Side effects may include constipation, edema, rash, and liver damage.
• Radiotherapy: Often combined with chemotherapy or used to treat residual lesions post-surgery. Side effects may include leukopenia and radiation pneumonitis. It is contraindicated for patients with poor overall health or severe heart, lung, or kidney dysfunction.

What lifestyle precautions should peripheral lung cancer patients take?

Ensure adequate nutrition, as cancer can deplete the body's energy. It is recommended to consume high-quality protein foods such as chicken, fish, and soy products.

Take medications as prescribed and do not adjust or stop them without medical advice. Follow the doctor's schedule for regular check-ups.

Family members should provide companionship to help patients avoid anxiety and depression.

How can peripheral lung cancer be prevented?

The exact cause of peripheral lung cancer is unclear, so there are no specific preventive measures. However, the following methods may reduce the risk:

• Smokers should quit, and avoid secondhand smoke.
• Wear masks in polluted environments or use protective masks when necessary.
• Wear radiation-protective clothing when exposed to radiation.
• Engage in regular exercise to boost immunity and reduce disease risk.
• Maintain a balanced diet with fresh vegetables and fruits.
• Schedule annual check-ups to detect and treat issues early.