(I) Preface
Primary lung cancer (hereinafter referred to as lung cancer) is one of the most common malignant tumors in China. According to the data released by the National Tumor Registry in 2014, in 2010, there were 605,900 new cases of lung cancer in China (416,300 men and 189,600 women), ranking first in malignant tumors (first in men and second in women) and accounting for 19.59% of new cases of malignant tumors (23.03% in men and 14.75% in women).
The incidence rate of lung cancer is 35.23/100,000 (49.27/100,000 for men and 21.66/100,000 for women). During the same period, the number of lung cancer deaths in China was 486,600 (336,800 for men and 166,200 for women), accounting for 24.87% (26.85% for men and 21.32% for women) of the causes of death from malignant tumors. The mortality rate of lung cancer was 27. 93/100,000 (39. 79/100,000 for men and 16. 62/100,000 for women).
Lung cancer screening in high-risk groups is beneficial for early detection of early lung cancer and improves the cure rate. Low-dose computed tomography (LDCT) is 4-10 times more sensitive than conventional chest radiography in detecting early stage lung cancer, and can detect early peripheral lung cancer early. According to the International Early Lung Cancer Action Plan, annual LDCT screening detects 85% of stage I peripheral lung cancers, with an expected survival rate of 92% at 10 years after surgery.
The U.S. National Lung Cancer Screening Trial demonstrated that LDCT screening reduced lung cancer mortality by 20%, making it the most effective lung cancer screening tool available. In China, LDCT is currently recommended for lung cancer screening in high-risk groups in a few regional pilot technical guidelines for cancer screening and early diagnosis and treatment.
The risk assessment factors for lung cancer screening proposed in the National Comprehensive Cancer Network (NCCN) guidelines include smoking history (current and past), radon exposure history, occupational history, cancer history, family history of lung cancer, disease history (chronic obstructive pulmonary disease or tuberculosis), and smoke exposure history (passive smoking exposure).
Risk status was divided into 3 groups.
(1) High-risk group: age 55-74 years, history of smoking ≥30 pack-years, history of quitting <15 years (category 1); or age ≥50 years, history of smoking ≥20 pack-years, with additional risk factors other than passive smoking (category 2B).
(2) Intermediate risk group: age ≥50 years, history of smoking or passive smoking exposure ≥20 pack years, no other risk factors.
(The NCCN guidelines recommend lung cancer screening for the high-risk group, but not for the low- and intermediate-risk groups.
In order to further standardize the diagnosis and treatment behavior of lung cancer in China, improve the level of lung cancer diagnosis and treatment in medical institutions, improve the prognosis of lung cancer patients, and ensure medical quality and medical safety, the Medical Administration of the National Health and Family Planning Commission commissioned the Professional Committee of Clinical Chemotherapy for Oncology of the Chinese Anti-Cancer Association to update and develop this standard on the basis of the original “Standard for the Treatment of Primary Lung Cancer (2010 Edition)” of the Ministry of Health.
(II) Clinical manifestations
When the disease develops to a certain degree, the following symptoms often appear: (1) irritating dry cough. (2) Blood in sputum or bloody sputum. (3) Chest pain. (4) Fever. (5) Shortness of breath. When the respiratory symptoms cannot be relieved by symptomatic treatment for more than 2 weeks, especially blood in sputum, irritating dry cough, or aggravation of the existing respiratory symptoms, the possibility of lung cancer should be highly alerted.
2.When lung cancer invades surrounding tissues or metastases, the following symptoms may appear.
(1) Hoarseness when the tumor invades the laryngeal nerve.
(2) Tumor invading superior vena cava, showing superior vena cava obstruction syndrome such as facial and neck edema.
(3) Tumor invades the pleura and causes pleural effusion, which is often bloody; large amount of effusion can cause shortness of breath.
(4) Tumor invading pleura and chest wall can cause continuous severe chest pain.
(5) Upper lobe apical lung cancer may invade and compress the organ tissues located at the entrance of the thorax, such as the first rib, subclavian artery and vein, brachial plexus nerve and cervical sympathetic nerve, producing severe chest pain, upper limb venous anger, edema, arm pain and upper limb movement disorder, ipsilateral upper eye and face drooping, pupil narrowing, eye inversion, facial sweating and other cervical sympathetic nerve syndrome manifestations.
(6) Recent neurological symptoms and signs such as headache, nausea, vertigo or blurred vision should be considered as possible brain metastases.
(7) Bone metastasis should be considered for persistent bone pain at fixed sites and elevated plasma alkaline phosphatase or blood calcium.
(8) Right upper abdominal pain, hepatomegaly, elevated alkaline phosphatase, aspartate aminotransferase, lactate dehydrogenase or bilirubin should be considered as possible liver metastases.
(9) Nodules may be palpated under the skin in case of subcutaneous metastasis.
(10) Hematogenous metastasis to other organs may show corresponding symptoms of metastatic organs.
(3) Physical examination
1. Most patients with early-stage lung cancer have no obvious positive signs.
2. Patients show extra-pulmonary signs of unknown cause and long duration, such as pestle and mortar fingers (toes), non-wandering joint pain, male breast enlargement, dark skin or dermatomyositis, ataxia and phlebitis, etc.
3.Patients with clinical manifestations highly suspicious of lung cancer, physical examination reveals vocal cord paralysis, superior vena cava obstruction syndrome, Horner’s sign, Pancoast’s syndrome, etc. suggesting the possibility of local invasion and metastasis.
4.Patients with highly suspicious lung cancer clinical manifestations and hepatomegaly with nodules, subcutaneous nodules and enlarged lymph nodes in the supraclavicular fossa on physical examination suggest the possibility of distant metastasis.
(IV) Imaging examination
Imaging methods for lung cancer mainly include X-ray chest radiography, CT, magnetic resonance imaging (MRI), ultrasound, nuclear imaging, positronemission tomography/computed tomography (PET-CT) and so on. They are mainly used for lung cancer diagnosis, staging, re-staging, efficacy monitoring and prognosis assessment. In the diagnosis and treatment of lung cancer, one or more imaging methods should be selected reasonably and effectively according to different examination purposes.
Chest X-ray: Chest X-ray is the basic imaging examination method before and after lung cancer treatment, which usually includes chest frontal and lateral radiographs. When there are doubts about the basic image of chest X-ray, or when there is a need to understand the details of the image displayed on the chest X-ray, or when there is a need to find other information that is helpful to the diagnosis, further imaging examination methods should be selected in a targeted manner.
2. Chest CT examination: Chest CT can display many image information that is difficult to be found on X-ray chest film, which can effectively detect early peripheral lung cancer, further verify the location and extent of lesion involvement, and also identify its benignity and malignancy, and is the most important and commonly used imaging means for lung cancer diagnosis, staging, efficacy evaluation and post-treatment follow-up.
For patients with initial diagnosis of lung cancer, the scope of chest CT scan should include both adrenal glands. For lesions in the chest that are difficult to diagnose qualitatively, CT-guided percutaneous lung aspiration biopsy can be used to obtain cytological or histological diagnosis. Thoracic LDCT scans are recommended for lung cancer screening in high-risk groups.
CT and thin-section reconstruction are the primary screening and diagnostic methods for pulmonary nodules. For isolated nodules ≤2 cm in the lung, thin-layer reconstruction and multiplanar reconstruction should be routinely performed; for nodules that cannot be clearly diagnosed at the initial diagnosis, CT follow-up intervals should be given depending on the size and density of the nodules; the changes in nodule size and density should be paid attention to during the follow-up, especially the increase of solid components in some solid nodules and the emergence of real components in non-solid nodules.
MRI examination: MRI examination can be used selectively in the chest to determine whether the chest wall or mediastinum is invaded; to show the relationship between the supraglottic sulcus tumor and brachial plexus nerve and blood vessels; to distinguish the boundary between hilar mass and pulmonary atelectasis and obstructive pneumonia; for patients who are contraindicated to inject iodine contrast agent, it is the preferred examination method to observe the invasion of mediastinum and hilar vessels and lymph node enlargement; it is also valuable to distinguish fibrosis after radiotherapy from MRI is also valuable in identifying fibrosis and tumor recurrence after radiotherapy.
MRI is particularly suitable for determining whether there is metastasis in brain and spinal cord, and brain-enhanced MRI should be used as routine preoperative staging examination for lung cancer; MRI has high sensitivity and specificity for metastasis in bone marrow cavity, and can be used according to clinical needs.
4.Ultrasound examination: It is mainly used to find out whether there is metastasis in abdominal solid important organs and peritoneal and retroperitoneal lymph nodes, and also used to examine bilateral supraclavicular fossa lymph nodes; for intrapulmonary lesions or lesions in the adjacent chest wall, it can identify their cystic and solid nature and perform ultrasound-guided puncture biopsy; ultrasound is also commonly used to extract and locate pleural effusion and pericardial effusion.
5.Bone scan examination: it is a routine examination for determining bone metastasis of lung cancer. When bone scan examination suggests suspicious metastasis, MRI, CT or PET-CT will be performed to verify the suspicious area.
6. PET-CT examination: recommended for those who have the conditions. It is the best method for lung cancer diagnosis, staging and re-staging, efficacy evaluation and prognosis assessment.
(V) Endoscopic examination
1. Bronchoscopy: Bronchoscopy is the most common method to diagnose lung cancer, including bronchoscopic brush examination, biopsy, needle aspiration and bronchial lavage to obtain cytological and histological diagnosis. The combined application of the above methods can improve the detection rate.
2. transbronchial needle aspiration (TBNA) and endobronchial ultrasound-guided transbronchialneedle aspiration (EBUS-TBNA): they can puncture lymph nodes and masses in the trachea or paratracheal area, and help to diagnose lung cancer and lymph node staging.
EBUS-TBNA can be performed in real time for the puncture of intrathoracic lesions and lymph node metastasis to obtain accurate pathological and cytological diagnosis of lung cancer lesions and lymph node metastasis, and it is safer and more reliable.
Transbronchial lungbiopsy (TBLB): It can be performed under the guidance of X-ray, CT, airway ultrasound probe, virtual bronchoscope, electromagnetic navigation bronchoscope and fine bronchoscope, and is suitable for the diagnosis of peripheralpulmonary lesions (PPL) in the outer and outer 2/3 of the lung.
4.Mediastinoscopy: As an effective method to confirm the diagnosis of lung cancer and assess the lymph node stage, it is currently the gold standard for clinical evaluation of mediastinal lymph node status of lung cancer.
5.Thoracoscopy: It can accurately diagnose and stage lung cancer. For early stage lung cancer that cannot be detected by TBLB and transthoracic needle aspiration (TTNA), especially for small nodular lesions in the lung, thoracoscopic wedge resection of the lesion can achieve clear diagnosis and treatment.
For middle and late stage lung cancer, biopsy of lymph nodes, pleura and pericardium, histological and cytological examination of pleural fluid and pericardial effusion can be performed under thoracoscopy to provide a reliable basis for the formulation of comprehensive treatment plan and individualized treatment plan.
(F) Other examination techniques
1.Sputum cytology examination: It is one of the simple and convenient non-invasive diagnostic methods to diagnose lung cancer.
2.TTNA: Puncture of intrathoracic masses or lymph nodes can be performed under CT or ultrasound guidance.
3.Thoracentesis: Thoracentesis can obtain pleural effusion for cytological examination.
4.Pleural biopsy: For pleural effusion of unknown diagnosis, pleural biopsy can improve the positive detection rate.
5.Superficial lymph node and subcutaneous metastatic node biopsy: For those with superficial lymph node enlargement and subcutaneous metastatic nodes, needle aspiration or biopsy should be routinely performed to obtain pathological diagnosis.