How should small cell lung cancer be diagnosed

With the aging of the population and the increasing air and environmental pollution, the number of people suffering from lung cancer is increasing every year. Small cell lung cancer is a type of lung cancer. Many patients do not know how to diagnose small cell lung cancer. Let us answer this question for you.

The earliest symptoms of small cell lung cancer are the same as those of other lung cancers, including cough, sputum, blood in sputum, fever, chest pain, back pain, and dyspnea. Progressive small cell lung cancer may cause weight loss, cervical lymphadenopathy (swelling), and upper body edema (swelling, superior vena cava occlusive syndrome) due to occlusion of the superior vena cava.

At present, the commonly used lung cancer tumor markers in clinical practice include: CEA (carcinoembryonic antigen), CYFRA21-1 (soluble fragment of cytokeratin 19), SCC (squamous cell carcinoma antigen), NSE (neuron-specific enolase) and ProGRP (progastrin-releasing peptide). Among them, CEA is mainly used for adenocarcinoma and large cell carcinoma, CYERA21-1 is mainly used for adenocarcinoma and squamous cell carcinoma, SCC is mainly used for squamous cell carcinoma, and NSE and ProGRP are both specific markers for SCLC.

As one of the important tumor markers for SCLC, NSE has many limitations: low sensitivity to early localized SCLC; abnormally elevated NSE values ​​may also occur in patients with other malignant tumors; plasma cannot be used for testing because red blood cells and platelets contain NSE, and hemolyzed samples are prone to false positives.

Gastrin-releasing peptide (GRP) is a gastrointestinal hormone that mainly stimulates the secretion of gastrin by gastric G cells, participates in the contraction of smooth muscle cells, and promotes cell-to-cell interactions. SCLC patients often have high levels of GRP expression and secretion, but the half-life of GRP is only 2 minutes, with poor stability and difficult to detect. As a precursor of GRP, pro-gastrin-releasing peptide (ProGRP) has a longer half-life and is more stable. It can be detected through serum or plasma samples to reflect the level of GRP. ProGRP is not expressed or expressed very low in normal epithelium, and is expressed at low levels in benign lung diseases and epithelial tumors. Studies have shown that if the judgment cutoff of ProGRP is set at 30pg/ml, ProGRP is detected in various solid tumors such as lung cancer, breast cancer, cervical cancer, colorectal cancer, liver cancer, pancreatic cancer, renal cell carcinoma and neuroendocrine tumors. ProGRP is significantly increased to 66% in SCLC, which is much higher than the expression in other tumors, proving that it has good specificity for SCLC.

The above is an explanation of how small cell lung cancer should be diagnosed. I hope the above content can help everyone better understand this disease.