On December 5, the sad news of Beijing men’s basketball player Ji Zhe’s death from lung cancer shook the whole Chinese sports circle.
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When the news came out of nowhere, many fans expressed surprise. The news came out of nowhere, and many fans were surprised to hear that Ji Zhe was born on October 14, 1986, just after his 33rd birthday.
While we all feel sorry for him, the lung cancer that took his life has also drawn attention.
What is metastasis of lung cancer?
What is metastasis?
In clinical practice, lung cancer from stage IA to some stage IIIA may be treated with surgery.
However, not all patients who undergo surgery are cured, and some will develop recurrence or metastasis, which can significantly affect survival.
Clinically, the 5-year survival rate for patients with stage N0 (no lymph node metastasis) is 60%-70%, while the 5-year survival rate for patients with stage M1 (distant metastasis has occurred) is less than 10%.
Why do recurrences and metastases occur even though the surgeon has cleaned the lesion? How to determine? How to treat?
Lung cancer cells are aggressive and can spread their “claws” to surrounding normal tissues, forming local infiltrates and/or regional lymph node metastases; they can also spread to the lungs through the airways and metastasize to other parts of the body through the blood and lymphatic systems.
What is the difference between metastasis and recurrence of lung cancer?
In clinical practice, lung cancer from stage IA to some stage IIIA may be treated with surgery.
However, not all patients who undergo surgery are cured, and some will develop recurrence or metastasis, which can significantly affect survival.
Clinically, the 5-year survival rate for patients with stage N0 (no lymph node metastasis) is 60%-70%, while the 5-year survival rate for patients with stage M1 (distant metastasis has occurred) is less than 10%.
Why do recurrences and metastases occur even though the surgeon has cleaned the lesion? How to determine? How to treat?
Lung cancer cells are aggressive and can spread their “claws” to surrounding normal tissues, forming local infiltrates and/or regional lymph node metastases; they can also spread to the lungs through the airways and metastasize to other parts of the body through the blood and lymphatic systems.
What is the difference between metastasis and recurrence of lung cancer?
Lung cancer recurrence is when the tumor fades away after treatment and is undetectable, and then the tumor is rediscovered in the body after a period of time.
The cancer can recur at the original site or may appear elsewhere in the body. The pathologic features of recurrent lung cancer are consistent with the initial presentation.
A study by the National Cancer Institute (NCI) found that metastases occurred more often than recurrences, regardless of the stage, grade, and type of lung cancer.
However, the type of cancer cell pathology was consistent with the primary lung cancer regardless of recurrence or metastasis.
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How does lung cancer metastasis occur?
The root of the problem behind lung cancer recurrence and metastasis may be “micrometastasis.
Micro-metastases, also known as invisible metastases, are tumor cells that have spread outside of the primary lesion and are not detected by conventional imaging techniques.
The lesion is less than 2 mm in diameter and can only be detected under the microscope. It metastasizes to other parts of the body, expands and grows through blood vessels or lymphatic.
Micrometastases significantly affect the prognosis of patients. It was found that for post-surgical stage I and II lung cancers, patients with micrometastases in the mediastinal lymph nodes had a significantly lower 5-year survival rate (18.8% with micrometastases compared to 64.1% and 44.4% for stage I and II patients without micrometastases, respectively).
In addition to the harm itself, undetected micrometastases can affect doctors’ judgment of tumor staging and lead to inadequate treatment.
Lung cancer micrometastases are currently detected mainly by immunological and molecular biology techniques, including immunohistochemistry (IHC), reverse transcription-polymerase chain reaction (PCR), and flow cytometry (FCM).
For micrometastases that occur in the blood circulation, certain biomarkers can be targeted for detection.
The presence of genetic mutations in lung cancer itself, such as the epidermal growth factor receptor (EGFR) gene, has improved detection rates in recent years through liquid biopsy techniques that detect circulating tumor cells (CTCs) and circulating tumor DNA (ctDNA).
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What are the most common sites of metastasis for lung cancer?
The most common sites of metastasis from lung cancer include within the lungs, brain, bone, liver, and adrenal glands.
What are the signs and symptoms of metastatic lung cancer?
When lung cancer metastasizes, different symptoms will occur depending on the location, as detailed in the following table.
| Symptoms | |
| Local recurrent metastases in the lung | Chronic cough (mostly irritating dry cough) Shortness of breath (may manifest as shortness of breath after activity) Recurrent infection (manifests as fever, cough, and sputum) Coughing up blood (manifests as blood in sputum or bloody sputum) Chest pain Hoarseness (compression of the recurrent laryngeal nerve) Difficulty swallowing (when compressing the esophagus) Superior vena cava syndrome (manifested by swelling of the face, neck, and arms) |
| Lymph node enlargement | |
| Brain metastases | Headache (may be severe) Vomiting (caused by increased intracranial pressure, mostly jet vomiting) Visual impairment (caused by increased intracranial pressure) Mental abnormalities (present when the prefrontal lobe of the brain is involved) Unilateral limb weakness or sensory abnormalities (present with parietal lobe involvement) Hemiparesis or ataxia (present with cerebellar involvement) Phantom sniffing (seen with temporal lobe involvement) |
| Bone metastases | Thoracic pain (rib involvement) Back pain (spinal cord metastases) Extremity pain (bone involvement of extremities or trunk) Paralysis (spinal vertebrae involvement) Pathological fractures Hypercalcemia |
| Liver metastases | Abdominal distention Loss of appetite epigastric mass Pain in the liver area jaundice, itching of the skin Confusion (occurrence of hepatic encephalopathy) |
| Adrenal metastases | Back pain Cushing’s syndrome (due to increased cortisol in the blood, causing high blood pressure, “full moon face”, “buffalo back” and stretch marks on the body) |
| Unexplained weight loss Fatigue, lethargy |
When one or more of these are present, you need to be seen in the hospital for imaging tests. Your doctor may also recommend a puncture biopsy.
How is lung cancer treated when it metastasizes?
First, once micrometastases are detected, they should be treated immediately. Surgery alone is not enough, but adjuvant chemotherapy is also needed. Treatment of lung cancer micrometastases is usually surgery (anatomic pneumonectomy) + hilar mediastinal lymph node dissection + adjuvant chemotherapy (platinum-containing two-drug regimen), or radiation therapy for patients who are not candidates for surgery.
For lung cancer micrometastases, it is unclear whether adjuvant radiotherapy after surgery can lead to improved survival.
Second, for lung cancer “oligometastases” (generally defined as no more than 5 systemic metastases and a relatively small metastatic tumor load, which is the “transitional stage” before extensive metastasis), physicians may choose systemic therapy (chemotherapy, targeted therapy, and immunotherapy) Combined local treatment (surgery or stereotactic radiotherapy).
Third, brain metastases are unique in that the blood-brain barrier often prevents drugs from reaching the lesions in the brain, or from reaching the concentrations needed for treatment.
Therefore, radiotherapy becomes the most common treatment. In the past, the most standard modality was whole-brain radiotherapy, but whole-brain radiotherapy can affect cognitive function, and its dominance in the treatment of brain metastases has been challenged as better treatments become available.
In recent years, more advanced radiotherapy modalities – stereotactic radiotherapy (SBRT), simultaneous additive intensity modulated radiotherapy (SMART), and radiotherapy that protects the cognitive function of the hippocampus – have entered the clinic.
In addition, for brain metastases from lung cancer with genetic mutations (e.g. EGFR, ALK, etc.), good results have been obtained with targeted drugs. The treatment paradigm of lung cancer brain metastases is beginning to change.
Despite the fact that lung cancer metastasis makes people talk about it, if it is detected early, there are more treatment options available and better treatment results.
Co-reviewed by: Guangdong Provincial People’s Hospital Guangdong Lung Cancer Institute Dr. Xue-Tao Li, Associate Chief Physician Wang Zhen