Lung cancer
It is a malignant tumor occurring in lung tissue and is divided into two types: non-small cell lung cancer and small cell lung cancer. Non-small cell lung cancer accounts for 85% to 90% of all lung cancers. Under the microscope, it is further divided into: squamous cell carcinoma, adenocarcinoma, large cell carcinoma, etc. according to the cellular characteristics, which have different growth and spreading patterns.
Smoking
Smoking is the most important factor causing lung cancer, and more than 80% of lung cancers are caused by smoking. Passive smoking also increases the risk of developing the disease, and the spouse of a smoker has a 30% increased risk of developing lung cancer. Other factors include: asbestos dust, radon gas, soot, chronic inflammation of the lung, chest radiation exposure and atmospheric pollution.
Clinical manifestations
Clinical manifestations vary according to the location and size of tumor growth. Early stage is often asymptomatic. As the tumor grows and invades, long-term cough, chest pain, hoarseness, weight loss and loss of appetite, coughing up rust-colored sputum or blood in sputum, chest tightness, unexplained fever, recurrent lung infections, wheezing and enlarged lymph nodes in the neck will appear. Brain metastases can cause headache, vision and speech changes, and epilepsy, and bone metastases can cause bone pain. Symptoms of metastasis can often precede respiratory symptoms.
Investigation methods
-CT of the chest and upper abdomen: CT can clearly show the location, size and shape of the tumor and can detect metastatic lymph nodes in the mediastinum. CT of the upper abdomen can reveal the presence of metastases in the liver and adrenal glands.
-Magnetic resonance imaging (MRI): It is advantageous to check whether there are metastases in the brain, spinal cord and vertebrae.
-Radionuclide bone scan (ECT): a sensitive method to screen for bone metastases, but confirmed by CT and MRI.
-Positron emission computed tomography (PET) and PET-CT: to understand the extent of tumor invasion and metastasis and to distinguish the nature of the mass.
-Bronchoscopy: A slim and flexible bronchoscope can be used to detect the mass and remove a small amount of tissue to check whether there are cancer cells.
Mass aspiration biopsy: under the guidance of CT, a fine needle is used to aspirate tissue and cells from the lung mass for pathological examination.
Treatment of lung cancer
Lung cancer treatment is very complex and rapidly evolving, requiring multidisciplinary professional doctors to provide high-quality standardized and individualized comprehensive treatment through good collaboration. Based on the most accurate staging as possible, a scientific treatment plan should be drawn up, and surgery, chemotherapy, radiotherapy and molecular targeted therapy should be arranged in a reasonable manner to fully utilize the advantages of various therapies. Weighing the pros and cons, patients will benefit to the maximum extent in terms of striving for a cure, prolonging survival, improving quality of life and relieving symptoms.
Surgical treatment
Commonly used surgical methods include wedge resection, lobectomy, and total resection of one lung.
Chemotherapy
Abbreviated as chemotherapy, it is the use of chemical drugs to kill cancer cells. After administered through blood vessels or orally, the drug enters the blood system and reaches all parts of the body. Chemotherapy is given once every 21-28 days for one cycle, usually for 4-6 cycles. Weak people are not suitable for active chemotherapy. Chemotherapy is often used in combination with surgery and radiotherapy.
Adjuvant chemotherapy: In order to reduce the recurrence rate of tumors, completing 4 cycles of a two-drug regimen of chemotherapy containing cisplatin after surgery can significantly prolong the survival of patients. This has been confirmed by numerous clinical studies.
Chemotherapy for patients with advanced disease: cisplatin or carboplatin in combination with one of the following agents: paclitaxel, docetaxel, gemcitabine, vincristine, irinotecan, etoposide, and vincristine. If the combination chemotherapy is not tolerated, chemotherapy is administered alone. Chemotherapy can increase the one-year survival rate of patients with advanced disease by more than a factor of one.
Second-line therapy: Docetaxel, gefitinib or erlotinib, and pemetrexed are available after initial chemotherapy has failed.
Radiation therapy
Abbreviated as radiotherapy, it is used for lung cancer that cannot tolerate surgery or cannot be removed by surgery due to adhesion of cancer tissue to surrounding tissues and organs. Radiotherapy is also used for those who have cancer residue after surgery. Palliative radiotherapy can relieve pain, bleeding and airway obstruction, and is also commonly used for the treatment of brain and bone metastases. External irradiation is usually given 5 days a week for a total of 4 to 7 weeks to complete the treatment volume. Radioactive particle implantation is brachytherapy, which is often used as supplemental dosing or palliative treatment for residual foci after external irradiation because of uneven distribution of radiation dose that leads to excessive tissue damage or insufficient tumor exposure.
Molecular targeted therapy
Epidermal growth factor receptor (EGFR) is closely related to the development of lung cancer and colorectal cancer, etc. Drugs such as gefitinib (ERSA) and erlotinib (Troche) can exert anti-tumor effects by controlling the activity of EGFR tyrosine kinase, and can control the development of some non-small cell lung cancers after oral administration. It is currently used mostly in patients who have failed previous chemotherapy. It has relatively high efficiency in non-smoking, adenocarcinoma, Asian, and female patients. Bevacizumab increases the effect of chemotherapy by interfering with tumor angiogenesis. Recent studies have found that the combination of antibodies against EGFR, such as cetuximab (Epiduo), with chemotherapy is more effective than chemotherapy alone in the treatment of non-small cell lung cancer.