Generality
Lung adenocarcinoma, or lung adenocarcinoma, is the most common lung malignancy in humans, whether they are smokers or nonsmokers.
The most important risk factors for lung adenocarcinoma are cigarette smoking, passive smoking and prolonged exposure to radon gas.
Typical symptoms consist of: intense cough, cough with blood, chest pain, dyspnoea, presence of blood in the sputum, fever, asthenia and chest pain.
The possible treatments of lung adenocarcinoma include: surgery, radiotherapy and chemotherapy.
So it's an adenocarcinoma
An adenocarcinoma is a type of carcinoma - therefore a malignant tumor - that originates from the epithelial cells of the exocrine glandular organs or from the epithelial cells of the tissues with secretory properties.
Examples of exocrine glandular organs are the breasts, pancreas or prostate; examples of tissues with secretory properties, on the other hand, are the layers of mucosa that line the inner wall of the airways, esophagus, stomach, colon or rectum.
What is lung adenocarcinoma
Lung adenocarcinoma, or lung adenocarcinoma, is a malignant tumor of the lung, which originates from the epithelial cells of the mucosal layers present in the lung.
Among the primary forms of lung cancer, lung adenocarcinoma has the sad distinction of being the most common.
PRECISE LOCATION OF ORIGIN
The precise site of origin of pulmonary adenocarcinomas is in the peripheral epithelial tissues of the lung; these tissues include mucus-secreting bronchial tree (terminal tract) cells and pulmonary acini cells.
What are the bronchial tree and pulmonary acini?
The bronchial tree is a fundamental tract of the lower airways and includes the respiratory structures known as bronchi and bronchioles. Above, it follows the trachea and, with its terminal portion, reenters the structure of the lungs.
A pulmonary acinus is a set of pulmonary alveoli, ie those small pockets of the lungs within which gaseous exchanges between the blood and the inhaled atmospheric air take place.
The pulmonary acini reside at the ends of the pulmonary bronchioles.
CLASSIFICATION OF PULMONARY ADENOCARCINOMA
The extreme histological heterogeneity, which characterizes lung adenocarcinoma, has led doctors and pathologists to distinguish the aforementioned malignant tumor into at least two types and different subtypes.
The two types of lung adenocarcinoma are:
- Non-invasive or minimally invasive adenocarcinoma, the subtypes of which are:
- L "adenocarcinoma in situ lung (or bronchioalveolar carcinoma)
- Minimally invasive lung adenocarcinoma
- Invasive adenocarcinoma, the subtypes of which are:
- Acinar predominant adenocarcinoma
- Papillary predominant adenocarcinoma
- The predominantly micropapillary adenocarcinoma
- Solid predominant adenocarcinoma
- Mucinous invasive adenocarcinoma
Causes
Like any tumor, lung adenocarcinoma also arises due to genetic DNA mutations, mutations that in this specific case affect - as mentioned - the cells of the epithelial tissues of the lungs.
At the biological-molecular level, the aforementioned mutational processes have, as a consequence, the impairment of the cellular processes of growth, division and death: cancer cells, in fact, grow and divide in an anomalous way, with a higher than normal rate, so much so that for these reasons, experts tend to define them with the terminology of "crazy cells".
WHAT FAVORS THE APPEARANCE OF MUTATIONS?
According to various scientific investigations, the main factor favoring the mutations that give rise to lung adenocarcinoma is cigarette smoking.
For smokers, in fact, the risk of developing lung cancer is 13 times higher than for a non-smoker.
Other contributing factors, important and worthy of mention, are:
- Exposure to radon. Radon is a radioactive, colorless and odorless gas that forms in the soil.
Exposure to radon is the second factor favoring all the various types of lung malignancy, including lung adenocarcinoma.
For obvious reasons, its combination with cigarette smoking further increases risk rates. - Passive smoking. The combustion of tobacco produces fumes containing toxic and carcinogenic substances, which can predispose to various malignant tumors, primarily lung cancer.
- Exposure to asbestos (or asbestos). Asbestos is a set of minerals (inosilicates and phyllosilicates), arranged in elongated bodies (the so-called "asbestos fibers") and capable of easily dispersing in the air (this involves their inhalation).
Asbestos is the main cause of another very aggressive type of malignant tumor: mesothelioma. - Exposure to other carcinogens, such as uranium, arsenic, vinyl chloride, nickel chromate, coal combustion products, methyl chloride ether, etc.
Some details about cigarette smoking and lung cancer:
- The more you smoke, the more likely you are to develop lung cancer.
In this regard, it is important to point out that the modest long-term smoker is in greater danger than the heavy smoker who has recently started smoking.
- Starting to smoke at a young age favors the onset of lung cancer, more than it favors starting in adulthood.
- Stopping smoking reduces the risk of developing lung cancer. The sooner you stop, the greater the health benefits.
EPIDEMIOLOGY
Furthermore, it is the most common form of lung cancer in women and, in general, in the entire population under the age of 45.
Symptoms and Complications
Lung adenocarcinoma is a rather subtle condition, as, very often, the clinical manifestations that characterize its presence appear only at an advanced stage of the disease.
The list of possible symptoms and signs of lung adenocarcinoma includes:
- Intense and persistent cough, with the production of a rather consistent sputum;
- Coughing up blood (hemoptysis);
- Presence of blood in the sputum (haemophtoe);
- Dyspnea (or shortness of breath) and other breathing difficulties. These disorders also arise due to not particularly intense efforts (eg: walking briskly, climbing stairs, etc.);
- Chest pain
- Fever;
- Asthenia;
- Loss of body weight;
- Pain in the shoulder or upper limb, located on the same side of the body as the diseased lung;
- Pneumonia of various kinds;
- Dysphagia;
- Dysphonia.
CAN IT BE ASYMPTOMATIC?
In a small percentage of cases, lung adenocarcinoma can be an asymptomatic condition, that is, without obvious symptoms and signs.
Experts have calculated that about 6% of people with lung cancer do not experience any noteworthy ailments, except when their health is already severely compromised.
COMPLICATIONS
At an advanced stage, lung adenocarcinoma tends to spread its cancer cells to other organs and tissues of the body, which are thus contaminated.
The aforementioned process is called metastasis; the cancer cells that become protagonists are called metastases.
In the specific case of lung adenocarcinoma, the spread of metastases generally affects the bones, although in some cases it also affects the brain.
From the point of view of symptoms, the involvement of the bones by metastases causes bone pain.
WHEN TO SEE THE DOCTOR?
The presence of persistent and / or bloody cough, dyspnoea, chest pain and asthenia should prompt immediate medical attention.
Diagnosis
In general, the diagnostic investigations that allow the detection of a lung adenocarcinoma begin with a careful physical examination and a careful medical history (or clinical history).
Then, they continue with some imaging tests, including: chest x-ray, chest CT, chest nuclear magnetic resonance (chest MRI), and chest PET scan.
Finally, they end with a lung biopsy.
In some particular circumstances, doctors may arrange for the execution of additional diagnostic tests, such as: sputum analysis, thoracentesis, a brain CT scan to see if there are brain metastases and a bone scan to understand if there are bone metastases. .
IMPORTANCE OF THE HISTORY
The anamnesis is important because it provides the first indications on the possible factors that have triggered the symptoms in progress.
For example, the fact that the patient is a heavy smoker or the fact that the patient has come into contact with asbestos are very significant information from a diagnostic point of view.
CHEST X-RAY, CHEST CATCH AND MRI OF THE CHEST
Chest x-ray, chest CT scan and chest nuclear magnetic resonance are three instrumental tests, each with its own specific functioning, which provide fairly accurate images of the lungs and other neighboring organs.
They are useful because they show a "possible mass of abnormal cells" with some degree of clarity.
While chest MRI is completely non-invasive, chest x-ray and chest CT scan involve exposing the patient to a certain dose of harmful ionizing radiation, so they are considered to be minimally invasive.
PET OF THE CHEST
The PET scan of the chest or any other anatomical region of the body provides information on the functionality of the body part examined.
LUNG BIOPSY
Lung biopsy is a minimally invasive diagnostic test, which consists in the collection of a sample of lung cells and its subsequent analysis in the laboratory.
The collection of the lung cell sample can take place in at least 3 different ways: by bronchoscopy (bronchoscopic biopsy), by fine needle aspiration (pulmonary needle biopsy) and by "open" surgery ("open" lung biopsy).
Lung biopsy is used to accurately delineate the type of lung cancer present and its stage.
What is the stage or staging of a malignant tumor?
The stage, or staging, of a malignant tumor includes all that information, collected during the biopsy, concerning the size of the neoplasm, its infiltrating power and its metastasizing capacity.
Treatment
Treatment of lung adenocarcinoma depends on the stage of the cancer and the patient's general health condition.
Generally:
- If the lung adenocarcinoma is localized (ie it has not yet metastasized), the therapy consists only in the surgical removal of the tumor mass.
- If lung adenocarcinoma has disseminated some of its cells in other organs and tissues of the body, treatments include not only surgery, but also chemotherapy and / or radiotherapy.
DETAILS ABOUT SURGICAL REMOVAL
There are 3 different ways a surgeon can perform the surgical removal of lung adenocarcinoma:
- By means of the so-called "wedge resection". It is the surgery to remove a small portion of the lung. Usually, surgeons use it when the tumor mass is small.
- By lobectomy. It is the surgery to remove one of the lobes that make up the lungs. Usually, surgeons use it when the tumor is of medium size.
Remember that the right lung has three lobes, while the left lung has two. - By pneumonectomy. It is the surgery for the total removal of a lung.
Typically, surgeons use it when the tumor is very large and has dramatically compromised normal lung anatomy.
CHEMOTHERAPY
Chemotherapy is the administration of drugs capable of killing all rapidly growing cells, including cancer cells.
Depending on some characteristics of lung adenocarcinoma, the treating physician can decide whether to opt for pre-surgical chemotherapy (also called neoadjuvant chemotherapy) or for post-surgical chemotherapy (also known as adjuvant chemotherapy).
According to what emerges from numerous clinical investigations, the chemotherapy adopted in case of lung adenocarcinoma with metastases would have the effect of prolonging the life of patients.
RADIOTHERAPY
Radiotherapy involves exposing the tumor mass to a certain dose of high-energy ionizing radiation (X-rays), in order to destroy the neoplastic cells.
When radiotherapy treatment takes place before surgery, we speak of neoadjuvant radiotherapy; when, on the other hand, radiotherapy treatment takes place after surgery, we speak of adjuvant radiotherapy.
In the case of lung adenocarcinoma, the therapeutic goal of radiotherapy is to reduce the symptoms associated with the presence of bone and / or brain metastases.
WHEN IT IS IMPOSSIBLE TO SEEK SURGERY
When the patient's general health condition is precarious and a surgical operation could be fatal, removal of the tumor by one of the above procedures is contraindicated.
If surgery is contraindicated, the only treatments available to patients remain chemotherapy and radiotherapy.
Often, in these situations, the treating doctors opt to combine radiotherapy treatments with chemotherapy ones, in order to obtain better results.
POST-THERAPEUTIC PHASE
At the end of the treatment, a series of periodic checks are planned, aimed at establishing the eradication or not of the pulmonary adenocarcinoma.
Post-therapeutic monitoring is important because it allows the attending physician to identify, with a certain timeliness, any tumor recurrences.
Prognosis
The prognosis of lung adenocarcinoma depends on several factors, including:
- The stage of the tumor
- The patient's general health condition
- The position more or less accessible to the surgeon of the tumor mass
In general, also due to the fact that the detection of the tumor mass is often late, lung adenocarcinoma tends to have a negative prognosis.
According to some statistical surveys, less than a fifth of patients with lung adenocarcinoma survive 5 years or more after tumor removal and / or radio / chemo-therapeutic treatment.
Prevention
Not smoking, avoiding exposure to secondhand smoke, avoiding exposure to radon and avoiding exposure to asbestos are the main preventive measures that doctors recommend to reduce the risk of lung adenocarcinoma.
