Original
2022-04-24
·
Hu Yang
Recently received a lung cancer patient on the network platform, this male patient in his 50s found lung cancer bone metastasis three years ago, there was no chance of surgery, fortunately, genetic testing suggested EGFR 19 exon mutation, so he began oral targeted drug Kemena, while combining pemetrexed chemotherapy in the local hospital for six cycles. After 18 months, the chest CT was reviewed to find a new lesion of the pleura, considering the progression of the disease, the patient was reluctant to puncture the secondary genetic test, so he directly orally took the third generation of oscitinib. Three months ago, the patient began to have lower limb weakness, the development was relatively slow, did two head magnetic resonance and full vertebral body magnetic resonance, neither of which was found to be vertebral metastases and brain metastases, and the patient did not take it seriously. In the past month, however, lower extremity weakness has gradually worsened, accompanied by severe headaches, nausea and vomiting, and from the symptoms, it looks like symptoms of increased intracranial pressure. After adequate communication, a lumbar puncture was done, and dysplasmic cells were found in the cerebrospinal fluid. At this point, the patient was finally diagnosed with lung cancer meningeal metastases.
Cancer cells can be said to be pervasive, everyone knows that lung cancer is prone to brain metastasis, 30% of all types of lung cancer patients will develop brain metastasis, and small cell lung cancer has a higher incidence. Lung cancer is prone to brain metastasis because the lung is an extremely vascularly rich organ, and there are anastomotic branches between the pulmonary blood vessels and the vertebral veins, and the fallen lung cancer cells can enter the brain directly without being filtered by the capillaries of the lungs. Once lung cancer occurs brain metastases, the prognosis is relatively poor, the survival period is very short, and the life expectancy is less than one year. However, you may not know that a more lethal and frightening site of metastasis than brain metastases is meningeal metastases.
About 4%-5% of lung cancer patients will eventually have meningeal metastases, and research data show that lung cancers with EGFR and other driver gene mutations have a higher probability of meningeal metastasis, close to 10%. When cancer cells metastasize directly to the meninges, they can enter the cerebrospinal fluid after detachment, flow to the meninges everywhere and cover the meninges on the outside of the spinal cord.
Why is meningeal metastase so terrible?
Symptoms are severe
Meningeal metastasis of lung cancer and brain metastasis of lung cancer are two different metastatic lesions. Because the meninges are very thin, it is easy to have severe headaches, dizziness, and increased blood pressure due to the stimulation of metastatic lesions, which can also cause reflex nausea, jet vomiting and other symptoms of cranial hypertension. In addition, other symptoms such as invasion of internal and external nerves are often combined, such as weakness of the limbs, blindness, seizures, etc., and the symptoms develop rapidly.
2. Difficulty in diagnosing the diagnosis
Patients with meningeal metastases lack specificity and are sometimes mistaken for other neurological problems, and in general, enhanced MRI is the imaging test of choice for finding lesions of brain parenchymal metastases. However, meningeal metastases are sometimes not found in enhanced magnetic resonance, and the diagnosis requires lumbar puncture, cerebrospinal fluid extraction, and malignant tumor cells found in cerebrospinal fluid to confirm the diagnosis.
3. Poor prognosis
Lung cancer meningeal metastases are one of the most serious complications of lung cancer, with a very poor prognosis and a median survival of only 4 to 6 weeks in untreated patients.
4. Poor treatment effect
The treatment effect of lung cancer meningeal metastases is poor, there are fewer chemotherapy drugs that can pass through the blood-brain barrier, and the effect of direct intrathecal injection of chemotherapy drugs is not satisfactory, and the compliance of patients with repeated lumbar puncture is also relatively poor. Oral targeted drugs in patients with sensitive gene mutations are relatively effective for meningeal metastasis, but if all the previous targeted drugs are resistant, they will face a situation where no drugs are available. Overall, despite aggressive treatment, meningeal metastases have a relatively low survival period of more than half a year.