Qualitative diagnostic method for lung cancer

In order to have a correct diagnosis of lung cancer, some clinical examination methods are indispensable. Generally speaking, a lung cancer patient needs to undergo the following types of examinations to be confirmed: tumor marker examination, blood biochemical examination, and imaging examination. Let's learn about them together.

1. Blood biochemical examination

There is no specific blood biochemical test for primary lung cancer. If alkaline phosphatase or blood calcium in lung cancer patients is elevated, bone metastasis may be considered, and if alkaline phosphatase, aspartate aminotransferase, lactate dehydrogenase or bilirubin is elevated, liver metastasis may be considered.

2. Tumor marker examination

(1) CEA: Thirty to seventy percent of lung cancer patients have abnormally high levels of CEA in their serum, but this is mainly seen in patients with advanced lung cancer. Currently, the examination of serum CEA is mainly used to estimate the prognosis of lung cancer and monitor the treatment process.

(2) NSE: It is the preferred marker for small cell lung cancer and is used for the diagnosis and monitoring of treatment response of small cell lung cancer. The reference value varies depending on the detection method and reagents used.

(3) CYFRA21-1: It is the preferred marker for non-small cell lung cancer. Its sensitivity for diagnosing squamous cell lung cancer can reach 60%. The reference value varies depending on the detection method and reagents used.

Three: Imaging examination

(1) Chest X-ray examination: This should include chest anteroposterior and lateral views. In primary care hospitals, chest anteroposterior and lateral views are still the most basic and preferred imaging diagnostic methods for initial diagnosis of lung cancer. Once lung cancer is diagnosed or suspected, a chest CT scan is performed.

(2) CT examination: Chest CT is the most commonly used and important examination method for lung cancer. It is used for the diagnosis and differential diagnosis, staging and follow-up after treatment of lung cancer. Hospitals with conditions should include the adrenal glands when performing chest CT scans on lung cancer patients. Enhanced scanning should be used as much as possible, especially for patients with central lung lesions. In addition, CT is a basic examination method for showing brain metastases. Patients with clinical symptoms or advanced patients should undergo brain CT scans, and enhanced scanning should be used as much as possible.

(3) Ultrasound examination: It is mainly used to detect metastasis of important abdominal organs and abdominal and retroperitoneal lymph nodes, and is also used to examine cervical lymph nodes. For pulmonary lesions or chest wall lesions adjacent to the chest wall, it can be used to identify the cystic and solid nature of the lesions and perform ultrasound-guided puncture biopsy; ultrasound is also often used to locate the extraction of pleural effusion.

(4) Bone scan: It has a high sensitivity in detecting lung cancer bone metastasis, but has a certain false positive rate. It can be used in the following situations: preoperative examination of lung cancer; patients with local symptoms.

(5) Further examination (transfer to another hospital for examination may be considered): ① Difficult cases; ② Patients request more comprehensive imaging examinations; ③ When further imaging examinations are clinically needed: for example, to determine whether the chest wall or mediastinum is invaded; to show the extent of the superior pulmonary sulcus tumor; to identify tumor recurrence and fibrosis after radiotherapy; to exclude intracranial metastasis, etc. MRI is required. PET-CT examinations are required for staging and follow-up after treatment of lung cancer.