What is lung cancer?
The growth and division of normal cells are very orderly. Only after the old cells die, new cells will be generated, or one cell will divide into two and then into several when the function of the body requires it, and when it is not required, the division is in a static state, which ensures the normal function of the body and ensures that the cells will not grow excessively. Unlike cancer, cancer cells are genetically altered due to external or internal factors, and their growth and division are in a disorderly state. If the cancer cells enter the blood or lymphatic fluid and enter other organs or tissues with the blood or lymph, the cancer cells will take root in these places and form new cancer tumors, which is then called tumor metastasis. The so-called lung cancer is this malignant cancer cells originated from the tissue cells of the lung, and it is the genetic change of the lung cells after being influenced by the outside world (such as long-term smoking).
How does lung cancer occur?
Research has demonstrated that most lung cancers are associated with smoking, and that about 85% of lung cancer patients are or have been smokers (Cancer Principles and Practice of Oncology. 6th ed. 2001:925-981), although there are certainly some lung cancer patients who do not smoke themselves who develop lung cancer, the cause of which may be related to inhaling “Another reason is that there are other carcinogenic factors in the environment, such as radioactive exposure, asbestos in the working environment, radon in mining or interior decoration materials, and automobile exhaust. etc.
The best way to prevent lung cancer is: quit smoking or never start smoking!
Are you or your family members ignoring these symptoms?
Since the lung is relatively large and deep inside the chest cavity, lung cancer rarely causes obvious symptoms or discomfort in the early stage due to the small lesions, and only when the tumor is larger and invades more of the surrounding tissues will there be more obvious symptoms, therefore, most lung cancers are often in the late stage of lung cancer when diagnosed. However, the earlier lung cancer is diagnosed and the more timely the treatment is, the better its prognosis will be. Therefore, for high-risk people, they should not ignore some early signs of lung cancer and should not consider it as a common cold or pneumonia when these early signs appear, but should go to the hospital for timely screening so as to detect lung cancer at an early stage, so as to seize the best time for treatment and improve the prognosis.
How to determine whether you or your family members are at high risk?
Do you smoke?
Do people around you smoke?
Do you work in an environment where someone smokes?
Are you over the age of 40?
Do you have an immediate family member with lung cancer?
Do you work in an environment with radioactive contamination or carcinogenic substances such as asbestos?
Common early signs of lung cancer include
Chronic cough that persists for a long time
Persistent chest pain
Cough with blood in the sputum
Shortness of breath, asthma, wheezing
hoarseness of voice
Recurrent episodes of bronchitis or pneumonia
Facial or neck edema
Unexplained loss of appetite or weight loss
Unexplained fever
Metastatic site symptoms such as bone pain
Of course, these symptoms can be caused by other things, but if you are also at high risk, it is recommended that you seek medical attention to detect or rule out lung cancer early.
What tests should I have?
For patients with possible signs of lung cancer, the doctor will perform targeted instrumental or ancillary tests to determine whether lung cancer is indeed present, taking into account the patient’s medical history and physical examination. For those who suspect lung cancer, sputum cytology, chest X-ray, etc. can be performed. If lung cancer needs to be diagnosed, some lung tissues from the lesioned areas need to be obtained by various means and then pathological examination can be performed. The commonly used lung cancer examination methods are as follows.
Chest X-ray
Chest X-ray is the most common and easiest way to show images of the lungs, heart, trachea, blood vessels in the lungs and lymph nodes. Usually your doctor will take two x-rays, one frontal and one lateral. Due to the resolution of the chest X-ray, it may be difficult to detect some small lesions, and your doctor will often recommend further tests such as CT and MRI.
CT scan, MRI imaging examination
CT and MRI examinations are used to visualize some organs and organs inside the body by X-ray and MRI respectively, forming a series of cross-sectional images of the lungs. These two examinations can see some subtle changes in the internal organs and are clearer than X-ray examinations, but they are often more expensive.
Positron Emission Tomography (PET)
PET is performed by injecting a special glucose carrying radioactive atoms into the body, and then the special photographic equipment of the PET machine can detect this radioactivity. Since cancer cells are more metabolically active and need more energy, they will absorb more glucose, and therefore, the tumor site will be more radioactive, so that the presence of the cancer can be detected.
Isotope Bone Scan
This type of test involves the injection of a radioactive bisphosphonate into the body, although its radioactivity when used for the test is often low and does not last long enough to affect the body. After this isotope is injected into the body, if there is cancer metastasis in the bones, the isotope activity tends to be higher so that a special imaging system can detect the presence of bone metastasis and determine the site of metastasis.
Fiberoptic bronchoscopy and percutaneous fine needle aspiration biopsy
In some cases, when it is difficult to confirm the diagnosis of lung cancer, it may be necessary to obtain some lung tissues directly for pathological examination, and then fiberoptic bronchoscopy or percutaneous needle aspiration biopsy may be used. The accuracy rate is relatively high, the confirmation rate can reach more than 90%, the complication rate is very low, the disadvantage is: invasive examination, the patient has some discomfort. The latter is to directly puncture the suspicious lesions near the chest wall through the skin of the chest and aspirate some tissues for pathological examination, which is only suitable for peripheral lung cancer near the chest wall but not for central lung cancer near the mediastinum, and there is a risk of certain complications.
How does lung cancer occur?
The pathological typing and staging of lung cancer is the basis for deciding the treatment plan of lung cancer. Different pathological types require very different treatment plans and the efficacy of treatment varies greatly. Therefore, the pathological type of lung cancer and its stage must be determined through various examinations and diagnostic tools before treatment is carried out, and only then can treatment be more targeted and effective.
The pathological types of lung cancer are often divided into two categories, one is non-small cell lung cancer (NSCLC) and the other is small cell lung cancer (SCLC). There are significant differences between these two types of lung cancer in terms of microscopic presentation, rate of growth and spread, and response to different treatments.
Non-small cell lung cancer (NSCLC)
NSCLC is the most common type of lung cancer, accounting for approximately 80% of all lung cancers. NSCLC usually grows and spreads more slowly than small cell lung cancer. As long as the diagnosis and treatment are timely, a good survival rate can be achieved, for example, the 5-year survival rate of stage I patients can reach 60-80%. These cells can be divided into three subtypes: squamous carcinoma, adenocarcinoma, and large cell carcinoma.
Small cell lung cancer (SCLC)
Small cell lung cancer is one of the more malignant types of lung cancer. This type of cell accounts for about 20% of all lung cancers, and the 5-year survival rate is often less than 10%. If left untreated, survival is often only 6-17 weeks. These cells are more sensitive to chemotherapy and radiotherapy, but even early stage small cell lung cancer has a very high recurrence rate, and on the contrary, surgical treatment is not very useful.
Staging of lung cancer
Staging is to fully understand the extent of lung cancer spread, which is very important for formulating treatment plan and judging prognosis. For example, a tumor in one stage is suitable for surgical resection treatment, while another stage may require combined chemotherapy or radiotherapy. The staging of non-small cell lung cancer and small cell lung cancer differs due to different tumor characteristics.
Staging of non-small cell lung cancer (NSCLC)
The most common staging method for non-small cell lung cancer is the TNM staging method, which considers three main aspects: the size/scope of the lung cancer, the invasion of lymph nodes associated with the lung cancer, and the presence of distant organ metastases.
Stage I: The tumor is confined to the lung and there is no lymph node metastasis, which is the early stage of lung cancer and the prognosis is often good
Stage II: the tumor is confined to the lung, with lymph node metastasis next to the tumor
Stage III: tumor is in the lung with metastasis in mediastinal lymph nodes or tumor cells in pleural fluid examination, Stage III is further divided into two types.
Tumor spreads only to the ipsilateral lymph nodes to become III-A
If the tumor spreads to the contralateral lymph nodes or supraclavicular lymph nodes, it is called III-B.
Stage IV: This is an advanced stage of the tumor, where the tumor has spread to organs other than the lung, such as the liver or bones.
Staging of small cell lung cancer (SCLC)
Small cell lung cancer (SCLC) is not applicable to TNM staging because of its high malignancy and metastasis can occur at an early stage, therefore, small cell lung cancer (SCLC) is usually classified in another way as
1, confined small cell lung cancer: the lung cancer is confined to one side of the chest and only invades one lung lobe and adjacent lymph nodes
2.Extensive small cell lung cancer: the cancer invades the contralateral lobe or other organs