lung tumor



OVERVIEW

Definition

The lung is an important organ of the respiratory system. Anatomically, the lung consists of bronchi, fine bronchioles, respiratory fine bronchioles, alveolar ducts and alveoli.

Lung tumors refer to tumors that occur in human lung tissue and are mainly classified into benign and malignant lung tumors.

Typing

Classification according to the nature of the tumor

Benign lung tumors commonly include misshapen tumors, chondromas, fibromas, smooth muscle tumors, hemangiomas, lipomas, bronchiolar cystadenomas and papillomas.

Mostly referred to as lung cancer, it is a malignant tumor originating from the bronchial mucosa or glands. In addition to lung cancer, it also includes other malignant tumors, such as lung sarcoma, lung lymphoma, lung carcinoid, lung metastasis, etc.

Classification according to tumor origin

It refers to tumors that originate from lung tissue.

Metastatic lung tumors refer to tumors from malignant tumors of any site that metastasize to the lungs through various metastatic modes, and also include simultaneous and heterochronous metastasis of ipsilateral/contralateral lung tumors.

The incidence of tumors from different sites metastasizing to the lungs varies, with thyroid, breast, kidney, choriocarcinoma, and osteosarcoma having the highest incidence, followed by hepatocellular carcinoma, gastric cancer, colorectal cancer, and prostate cancer.

Incidence

According to the national cancer report released by the National Cancer Center 2022, the incidence of lung cancer in China in 2016 was as follows [1]:

Lung cancer is still the most common malignant tumor in China, and about 657,000 people lost their lives in 2016 due to lung cancer.

The number of new cases of lung cancer reached 828,000 in 2016, an increase of 41,000 compared with that of 2015.

The incidence of lung cancer is estimated to be 49.78/100,000 in the male population and 23.70/100,000 in females.

In urban areas, the incidence of lung cancer is 36.7/100,000 and in rural areas it is 35.2/100,000.

Etiology

The causes of different types of lung tumors vary, and only the key causes are described below.

For more information on the causes of lung tumors, please refer to the disease-specific articles.

Causes

Different types of lung tumors have different causes, which are listed below:

Benign lung tumors

Lung misshapen tumors are not really tumors, but are caused by abnormal bronchial embryonic development.

Pulmonary hemangioma is a rare congenital disorder that may be associated with overdevelopment or defects in normal blood vessels.

Pulmonary chondrosarcoma may occur in association with abnormal embryonic development.

Pulmonary lipoma may be associated with genetic factors, poor lifestyle habits, inflammatory stimuli, and abnormal lipid metabolism.

Lung smooth muscle tumor may be related to chronic inflammatory stimulation, abnormal hormone secretion, gene mutation, and genetic factors.

Malignant lung tumor

Lung cancer is associated with smoking, history of chronic obstructive pulmonary disease (COPD), occupational exposure, ionizing radiation, heredity, and other factors.

Lung metastases are the result of primary tumor metastasis to the lungs through blood, lymph, and direct infiltration.

Lung lymphoma is mostly spread by direct infiltration of mediastinal malignant lymphoma or hematogenous metastasis from distant lesions to the lungs.

Primary pulmonary sarcoma is rare, and most of them are deterioration of benign tumors, including smooth muscle sarcoma, fibrosarcoma, neurofibrosarcoma, hemangioendothelioma, chondrosarcoma, and liposarcoma, etc., with fibrosarcoma as the mainstay.

Lung carcinoid tumor is a kind of neuroendocrine tumor, the etiology of which is currently unknown and may be related to genetic factors.

Symptoms

There are mostly no special clinical symptoms in the early stage of lung tumors, and the symptoms of different types of lung tumors are different. For more information on symptoms, please refer to the section on symptoms of the corresponding disease.

Major Symptoms

Benign lung tumors

Most of the benign lung tumors are asymptomatic, with atypical clinical signs. Cough, shortness of breath, chest pain, hemoptysis and so on will appear when the tumor continues to grow and oppress the surrounding organs or tissues.

When the tumor continues to enlarge and obstruct the bronchial tubes, it may cause obstructive pneumonia, with persistent cough, mucopurulent sputum, dyspnea, high fever, chills and so on.

Malignant lung tumor

Cough is the most common symptom of lung tumor patients when they visit the doctor, and most patients have cough symptoms when they visit the doctor.

It is mostly irritating dry cough with no sputum or a little white mucus sputum.

When secondary lung infection, or mucinous adenocarcinoma, mucopurulent sputum may appear.

It is one of the early first symptoms in patients with malignant lung tumor.

It usually manifests as sputum with blood in it, and hemoptysis can occur when the tumor erodes large blood vessels.

Hemoptysis is an important symptom suggestive of malignant lung tumor.

Some patients with malignant lung tumor have dyspnea as the first symptom.

It mostly manifests as chest tightness, shortness of breath, and some patients may have chest pain.

Partial obstruction of bronchial tubes can cause localized rales, while tumors located in the large airways, especially in the main bronchus, can cause limited wheezing symptoms.

It can be caused by necrosis of tumor tissue or by secondary pneumonia (e.g., obstructive pneumonia).

Fever is characterized by prolonged and recurrent, sometimes good and sometimes bad, and difficult to cure.

Intermittent moderate or low fever is common, and high fever may be present when combined with infection.

The tumor may cause consumption, loss of appetite, etc., resulting in the patient experiencing malaise with weight loss.

Other symptoms

Invasive symptoms

Extrinsic symptoms are symptoms caused by the primary tumor invading neighboring organs and structures, mainly seen in malignant tumors.

Symptoms usually include a feeling of fullness in the head and difficulty in breathing. Cough, pain and dysphagia are rare. Physical examination mainly shows edema of the head and neck and even both upper limbs, varicose veins in the neck and upper chest (veins are in the form of cords and are clearly visible), capillary dilatation, etc. The tumor is usually found in the eyeball on the side where the tumor occurs.

The side where the tumor occurs has sunken eyes, drooping upper eyelids, small eye fissures, narrow pupils, as well as the absence of facial sweating.

Also known as Pancoast syndrome, it is usually significantly more common in males than in females, more common on the right side than on the left, and can occur at any age.

It manifests as persistent pain in the shoulder, forehead, neck, upper arm and even hand on the diseased side, which is progressively aggravated, and some of them even have upper limb dysfunction, and Horner’s syndrome on the diseased side can also be found.

Involvement of recurrent laryngeal nerve causes hoarseness.

Some lung cancer patients consult the doctor with this as the first symptom.

It is mostly caused by direct invasion of tumor or lymph node metastasis compressing esophagus.

Invasion of pleura can cause pleural effusion (hydrothorax), which is often a large amount of bloody effusion.

At first, the patient gradually feels chest tightness and may have chest pain. As the amount of fluid increases, chest pain decreases or disappears, but dyspnea increases.

Distant metastatic symptoms

Metastatic symptoms refer to the symptoms caused by distant metastasis of the tumor, and the most common sites of distant metastasis are brain, bone, liver and so on.

The most common sites of distant metastasis are brain, bone, liver, etc. Early stage may be asymptomatic.

Symptoms of central nervous system often appear:

Commonly found in ribs, spine, pelvis and long bones.

May be asymptomatic in the early stages, with localized pain and pressure in the later stages.

If the spinal metastasis compresses or invades the spinal cord, it can lead to urinary and fecal incontinence or paraplegia.

Hepatomegaly and pain in the liver area may occur.

It may be accompanied by loss of appetite, nausea, emaciation, and elevated aminotransferases such as aspartate aminotransferase (AST) or bilirubin.

It tends to metastasize first to the hilar lymph nodes along the lymphatic return pathway and then to the mediastinal and supraclavicular lymph nodes.

The enlarged superficial lymph nodes are hard and may be fused into clusters, and are not accompanied by pressure pain.

Complications

Complications of benign lung tumors are rare, and patients with malignant lung tumors can develop a series of complications, mainly:

Endocrine abnormalities

Lung tumor cells will secrete some biologically active hormones, such as pro-adrenal hormone, parathyroid hormone, etc. Therefore, symptoms such as abnormal secretion of antidiuretic hormone, ectopic ACTH secretion, ectopic parathyroid hormone, and hypercalcemia will occur.

Neuromyopathies

Most of them are of unclear etiology and can appear before or after the onset of lung cancer, and can present with myasthenia gravis syndrome, polymyositis, and carcinomatous neuromyopathy.

Hematologic abnormalities

Cancer cells may affect the coagulation function, and clinical symptoms such as wandering thrombophlebitis, disseminated intravascular coagulation with hemorrhage and anemia may appear.

Consultation

Department of Medicine

Respiratory medicine

When patients develop symptoms such as cough, sputum, hemoptysis, dyspnea, fever, etc., it is recommended to seek medical treatment promptly.

Thoracic Surgery

If a lung tumor is diagnosed and requires diagnostic operation or surgical treatment, it is recommended to seek timely medical treatment.

Medical Oncology

If a patient is diagnosed with a middle or late-stage malignant lung tumor, he/she can choose medical oncology to receive medical drug treatment.

Preparation for medical treatment

Consultation: Registration, Preparation of Documents, Frequently Asked Questions

Tips for Medical Consultation

Patients may need to have a chest X-ray or CT scan. Avoid wearing metal clothing such as shirts with buttons, blouses with sequins, and dresses with zipper openings.

Record the symptoms, duration and other relevant information to give your doctor more information.

Checklist for preparing for medical treatment

Pay particular attention to the time of onset of symptoms, special manifestations, etc.

Has there been coughing and sputum, and for how long?

Is there blood in the sputum?

Is there any chest tightness and shortness of breath, and how long has it been?

Is there any unexplained weight loss?

Is there fever and what is the highest temperature?

Any history of other tumors, such as thyroid cancer, breast cancer, etc.?

Are you a smoker, for how long and how many cigarettes per day?

What is your occupation?

Is there any family history of malignant tumors such as lung cancer?

Are there any other concomitant diseases, such as chronic obstructive pulmonary disease (COPD)?

Any history of drug or food allergies?

Examination results in the last six months, which can be brought to the doctor’s office

Imaging tests: chest X-ray, CT.

Laboratory tests: routine blood test, routine stool test, routine urine test, biochemical test

Other tests: endoscopy, pathologic examination.

Diagnosis

Diagnosis is based on

Medical history

The patient may have the following medical history.

History of primary tumor, such as thyroid cancer, breast cancer, etc.

History of smoking and passive smoking (secondhand smoke).

History of COPD (chronic obstructive pulmonary disease).

History of occupational exposure to asbestos, radon, beryllium, chromium, cadmium, nickel, silica, soot and coal smoke.

Family history of malignant tumors.

Clinical manifestations

Patients may have cough, sputum, hemoptysis, dyspnea, and fever.

There are usually no abnormal physical signs.

Patients with advanced stage may have pleural friction, decreased breath sounds, and turbidity on percussion.

Superficial lymph nodes such as axillary lymph nodes and supraclavicular lymph nodes may be enlarged.

Laboratory Tests

Before treatment, patients need to undergo blood routine, liver and kidney function, electrolyte, blood coagulation analysis and other necessary general examinations, which can determine the general condition of the patient, and find out whether there is infection, anemia, thrombocytopenia, abnormal liver and kidney function, electrolyte disorders, abnormal coagulation function and other conditions.

Commonly used tumor markers include glycan antigen 15-3 (CA15-3), carcinoembryonic antigen (CEA), neuron-specific enolase (NSE), cytokeratin fragment 19 (CYFRA21-1), gastrin-releasing peptide precursor (ProGRP), and squamous epithelial cell carcinoma antigen (SCC).

Combined testing of the above indicators can provide additional evidence for confirming the diagnosis of malignant lung tumors, and is also used for postoperative recurrence or metastasis monitoring.

Imaging

Ultrasonography is mainly applied to the observation of supraclavicular lymph nodes, liver, kidney and other parts and organs metastasis, providing information for tumor staging.

Ultrasound-guided puncture can be used to perform puncture biopsy of lung tumors, supraclavicular lymph nodes, and metastases in parenchymal organs to obtain specimens for histological examination.

Chest X-ray is the basic examination method for detecting lung tumors and providing preliminary information about the lesion.

It has limited diagnostic value for early lesions, and once malignancy is suspected, chest CT should be performed promptly.

Chest CT is currently the most important and commonly used imaging examination method in the diagnosis, staging, efficacy evaluation and post-treatment follow-up of lung tumors.

It can effectively detect early lung tumors and further evaluate the location of the tumor, the extent of involvement and lymph node metastasis, which can help clinical staging.

CT examination of other parts including brain, liver and kidney can help doctors clarify whether there are distant metastases.

It can help determine the scope and location of tumor invasion, etc. It can also be used for post-treatment efficacy assessment and review examination.

It can also show the relationship between the tumor and the surrounding tissues and organs, lymph node metastasis, etc., which can provide a more reliable basis for the follow-up treatment.

MRI of other parts can determine whether metastasis has occurred or not.

Short for bone scan, it is a routine examination to determine whether bone metastasis has occurred or not.

When bone scanning suggests suspected bone metastasis, MRI, CT or PET-CT should be performed to verify the suspected site.

PET-CT is the best method for diagnosis, staging and re-staging, efficacy evaluation and prognosis assessment.

It can also be used for radiotherapy localization and target area outlining.

Bronchoscopy

It is a better means to diagnose lung tumors occurring in the central part.

It can directly observe the morphology, size, distribution and invasion of neighboring organs, and directly biopsy the tumor.

Pathologic examination

Pathological diagnosis of lung biopsy specimens is mainly to clarify the presence or absence of tumor and the histological type of the tumor, which is the “gold standard” for the final diagnosis of lung tumor.

For advanced inoperable patients, pathological diagnosis should be subtyped as far as possible, and for cases with atypical morphology, immunohistochemical staining should be combined to further clarify the diagnosis.

Differential diagnosis

Lung tumors are mainly benign and malignant, but also need to be differentiated from tuberculosis, pneumonia and other diseases.

Tuberculosis

Similarity: Tuberculosis patients may also have the symptoms of coughing, coughing up sputum or blood in sputum, or even hemoptysis, and the tuberculosis ball formed by tuberculosis is more difficult to be distinguished from peripheral lung cancer in the imaging examination.

Differences: Tuberculosis is prevalent in young people, with special symptoms such as low afternoon fever and night sweats, which can be reduced or disappeared after anti-tuberculosis treatment. It can be determined by pathological examination, in which Mycobacterium tuberculosis is visible in tuberculosis and cancer cells are visible in lung cancer.

Pneumonia

Similarities: the same symptoms such as fever, cough and sputum. Chronic inflammation in the lungs acts for a long time, forming lumpy inflammatory pseudotumor, which is also easy to be confused with lung cancer.

Differences: Antibiotic treatment for pneumonia is effective. When pneumonia occurs repeatedly in the same area, the possibility of lung cancer should be considered, and biopsy samples can be taken from the lesion area for pathologic differential diagnosis.

Treatment

Purpose of treatment

Treatment principle

Surgical treatment

Surgical treatment is the first choice and the most important treatment for lung tumors.

Benign lung tumors

When benign lung tumors are small, without obvious clinical symptoms, and have no effect on the surrounding tissues or organs, they can be followed up for observation and regular review of chest CT.

When benign lung tumors gradually increase in size, have obvious clinical symptoms, or have the tendency of malignant transformation, they should be operated as soon as possible, and generally do not need drug treatment.

Malignant lung tumor

Surgery should be preferred according to the specific conditions of the patients, and complete resection of the tumor should be strived for in order to reduce recurrence and metastasis of the tumor.

According to the surgical area of resected lung tissue, it is divided into wedge resection, segmental resection, lobectomy, total pneumonectomy and extended resection.

According to the size of incision and trauma, it can be further divided into conventional open thoracotomy, small incision open thoracotomy and thoracoscopic minimally invasive surgery.

Chemotherapy

Chemotherapy is mainly for malignant lung tumors, through oral or intravenous injection of chemical drugs to achieve the purpose of killing tumor cells or toe tumor cells continue to grow.

Commonly used chemotherapeutic drugs include paclitaxel, carboplatin, cisplatin, gemcitabine, pemetrexed, docetaxel and so on.

The need to combine with other treatment modalities such as surgery, radiotherapy, targeting, immunotherapy, etc. can be considered according to the patient’s specific situation.

Radiation therapy

Radiotherapy is a local treatment method using radiation to treat tumors and is an important means of treating malignant lung tumors.

It includes radical radiotherapy, palliative radiotherapy and comprehensive radiotherapy.

Other treatments

Targeted therapy

Targeted therapy is to take the tumor cells as the target point, the drugs are similar to guided missiles, the drugs enter the body will specifically select the cancer-causing sites to bind and have an effect, inhibit the growth of tumor cells or even remove the tumor cells, without or less affecting the normal tissue cells around the tumor.

Commonly used drugs include Ossitinib, Crizotinib, Entrectinib, Lapatinib, Gefitinib, Loratinib, Entrectinib, Dabrafenib and so on.

Immunotherapy

Immunotherapy is to activate the body’s immune system through immune drugs, relying on its own immune function to kill cancer cells and tumor tissues.

Commonly used drugs include Pabolizumab, Navulizumab, Sindilizumab, Duvarizumab, Atelizumab, Tirilizumab, Sugilizumab and so on.

Interventional therapy

Tumor interventional therapy is a therapeutic method to kill tumors by using physical energy (radiofrequency, microwave, ultrasound, etc.) or chemical substances to gather at the tumor site with the help of imaging technology guidance (angiography, ultrasound, CT, magnetic resonance, luminal microscopy, etc.).

For patients who cannot be operated or whose systemic chemotherapy is ineffective, interventional therapy can be used to block the tumor blood vessels and cut off the blood supply to the tumor, so as to achieve the therapeutic purpose.

Prognosis

Cure

Benign lung tumors and early malignant lung tumors can be cured by surgical resection.

Advanced malignant lung tumors usually do not have the chance of surgery, and the progression of the disease can be slowed down by chemotherapy, radiotherapy and targeted therapy, but most of them have a poor prognosis.

Prognostic factors

Prognostic factors are factors that have an impact on the overall survival and quality of life of patients.

Clinical stage and tumor nature have a greater impact on prognosis: the earlier the stage, the better the prognosis; benign tumors have a better prognosis than malignant tumors.

Daily

Daily Management

Dietary management

Diet should be light, easy to digest and nutritious.

It is recommended to consume more protein-rich food such as beef and mutton, fish, eggs, milk, etc. to replenish sufficient energy for the body.

Consume more foods rich in vitamins and dietary fiber, such as fresh vegetables and fruits.

Avoid cold, greasy, spicy and irritating foods such as fried chicken, cream and animal offal.

Life management

Quit smoking and drinking, avoid strenuous work, have a regular routine, avoid staying up late and get enough sleep.

Maintain a healthy weight, take appropriate activities such as slow walking, tai chi, qigong, breathing exercises, etc., and avoid crowded places.

During radiotherapy, avoid rubbing and scratching the skin, keep it clean and dry, and ban the use of soap and towel for bathing.

Psychological support

A good mood and mindset cannot be replaced by drugs.

After diagnosis the patient may develop a sense of fear and may be afraid of pain, abandonment and death. With the encouragement and help of doctors, family and friends, patients need to get rid of their fears as soon as possible, face up to the disease, actively follow the doctor’s instructions, and have an optimistic attitude towards the prognosis.

Family members should pay attention to listening to the patient’s heart, improve the patient’s psychological tolerance, and relieve anxiety symptoms.

It is recommended that the patient’s family give support so that the patient can face the surgery and other treatments positively with a good mindset.

During and after treatment, family members are advised to encourage the patient to do work and household chores that are within his/her ability, so as to reintegrate into social roles.

Disease monitoring

Monitor the patient’s clinical symptoms, such as cough, sputum, hemoptysis, blood in sputum, chest pain, dyspnea, etc., and pay attention to whether the symptoms reappear or worsen.

Follow-up

Importance of follow-up

Regular follow-up helps to detect recurrence and metastasis of lung tumor in time. The specific time and items for follow-up should be based on the clinician’s instructions.

Follow-up Period

The follow-up period is: within 2 years after treatment, every 3 months; within 2 to 5 years, every 6 months; after 5 years, every year.

If there is any discomfort, consult the doctor at any time.

Review items

Tumor markers, chest CT, abdominal ultrasound and other examinations are required for review, and abdominal CT, cranial and brain enhanced MR, PET-CT and other examinations are feasible when necessary.

Prevention

Cancer prevention is mainly to reduce the risk of developing cancer. It can be broadly divided into daily prevention and regular screening.

Daily prevention: To reduce or avoid the risk factors of lung tumors and increase their protective factors.

Regular screening: It means that the general population should do a good job of regular physical examination, and high-risk groups are recommended to consult a professional doctor and follow the doctor’s instructions for tumor screening.

Daily prevention

Adhere to smoking cessation and alcohol restriction. Stop smoking (including cigarettes, e-cigarettes, etc.) and stay away from passive smoking. If necessary, reduce any form of alcohol intake.

Take occupational precautions. People who are at risk of occupational exposure should take precautions to avoid exposure to carcinogens such as asbestos, chromium and nickel.

Avoid air pollution. Indoor pollution, such as passive smoking, open-flame coal heating, and exposure to grease fumes.

Do personal protection outside. Avoid going out and exercising when the atmosphere is severely polluted; if necessary, wear an anti-haze mask.

Timely and standardized treatment. Patients with respiratory diseases such as chronic obstructive pulmonary disease (COPD) or diffuse pulmonary fibrosis should receive timely and standardized treatment.

Healthy lifestyle. Try to have a regular routine, moderate exercise, weight control and balanced nutrition.

Regular screening

For patients with COPD and other primary diseases, people with a history of primary tumors or a family history of tumors should undergo regular medical checkups or retests.