Marian Grosser studied human medicine in Munich. In addition, the doctor, who has a wide range of interests, has ventured on a number of exciting detours: studying philosophy and art history, working in radio and finally also for Netdoktor.
Martina Feichter studied biology with pharmacy as an optional subject in Innsbruck, where she also delved into the world of medicinal plants. From there, it was not far to other medical topics that still captivate her today. She trained as a journalist at the Axel Springer Academy in Hamburg and has been working for NetDoktor since 2007 – first as an editor and since 2012 as a freelance writer.
Lung cancer (bronchial carcinoma) is one of the most common cancers in Europe. The most important risk factor is smoking. Passive smoking can also lead to lung cancer. The malignant tumor can be treated in various ways, such as chemotherapy and surgery. Still, lung cancer is rarely curable. Learn more about how to recognize and treat lung cancer, what causes, forms and stages there are, and what the prognosis is.
Lung cancer: Brief overview
- SymptomsOften no symptoms or only non-specific symptoms at first (such as persistent cough, chest pain, fatigue). Later z.B. Shortness of breath, mild fever, severe weight loss, bloody sputum.
- Main forms of lung cancer: The most common is non-small cell bronchial carcinoma (with subgroups). Rarer, but more aggressive is the small cell bronchial carcinoma.
- causes: Smoking in particular. Other risk factors are z.B. Asbestos, arsenic compounds, radon, a high level of pollutants in the air and a diet low in vitamins.
- InvestigationsX-rays, computed tomography (CT), magnetic resonance imaging (MRI), examination of tissue samples (biopsies), positron emission tomography (usually in combination with CT), blood tests, examination of sputum, collection and examination of "lung water" (pleural puncture)
- Therapy: surgery, radiation therapy, chemotherapy, possibly. other methods.
- PrognosisLung cancer is usually diagnosed late and is therefore rarely curable.
Lung cancer: signs (symptoms)
Lung cancer (lung carcinoma) causes often no or only non-specific symptoms at first. These include fatigue, coughing or chest pain. But such complaints can also have many other causes, for example a cold or bronchitis. This is why lung cancer is often not detected in its early stages. This then complicates the therapy.
More pronounced signs calls Lung cancer in advanced stages hervor. Then, for example, rapid weight loss, bloody sputum and shortness of breath may occur.
If the lung cancer has already metastasized to other parts of the body, there are usually additional symptoms. For example, metastases in the brain can damage the nerves. Possible consequences include headaches, nausea, impaired vision and balance, or even paralysis. If the cancer cells have affected the bones, arthritis-like pain may occur.
Read more about the different signs of lung cancer in the article Lung cancer: symptoms.
Lung cancer: stages
Lung cancer, like any other cancer, develops when cells degenerate. In this case it is cells of the lung tissue. The degenerated cells multiply uncontrollably and displace healthy tissue in their vicinity. Later, individual cancer cells can spread throughout the body via the blood and lymph vessels. Often they then form a metastasis somewhere else.
A lung cancer disease can thus be advanced to different degrees. For example, we talk about early stage or – in the worst case – end stage lung cancer. But these are not precisely defined terms. Physicians therefore usually use the so-called TNM classification: it allows the individual lung cancer stages to be described precisely. This is important because the treatment and life expectancy of a patient depends on the stage of the lung cancer in question.
Lung cancer: TNM classification
The TNM scheme is an international system to describe the spread of a tumor. Where:
- "T" for the size of the Tumors
- "N" for the involvement of lymph nodes (Nodi lymphatici)
- "M" for the presence of Metastases
For each of these three categories assign a numerical value. It indicates how advanced a patient’s cancer is.
The exact TNM classification for lung cancer is complex. The following table is intended to give a rough overview:
Tumor character at diagnosis
Carcinoma in situ ("tumor in situ")
Early cancer form: the tumor is still confined to its origin, i.e., has not yet grown into surrounding tissue.
Tumor is max. 3 cm in largest diameter, surrounded by lung tissue or lung pleura, and the main bronchus is not affected.
The first branches of the trachea in the lungs are called the main bronchi.
T1 can be specified even more precisely and is therefore subdivided into:
- T1a(mi): minimally invasive adenocarcinoma
- T1a: largest diameter< 1 cm
- T1b: largest diameter> 1 cm and< 2 cm
- T1c: largest diameter> 2 cm and max. 3 cm
The largest diameter of the tumor is more than 3 and max. 5 cm OR the main bronchus is affected OR the pleura is affected OR the tumor has partially collapsed the lung (atelectasis) or inflamed it in part or in its entirety
Further classification in:
- T2a: largest tumor diameter> 3 cm and max. 4 cm
- T2b: largest diameter> 4 cm and max. 5 cm
The largest diameter of the tumor is at least. 5 cm and max. 7 cm OR the inner chest wall (incl. Lung pleura), the phrenic nerve or the pericardium is affected OR there is an additional tumor node in the same lobe of the lung as the primary tumor
The largest diameter of the tumor is> 7 cm OR other organs are affected (z.B. diaphragm, heart, blood vessels, trachea, esophagus, vertebral body) OR there is an additional tumor node in another lung lobe
Involvement of lymph nodes on the same (body) side as the tumor (ipsilateral), of lymph nodes around the bronchi (peribronchial) and/or of lymph nodes at the lung root of the same side
Lung root = site of entry of pulmonary vessels and main bronchi into the lung
Involvement of lymph nodes in the mediastinum and/or at the outlet of both main bronchi of the same side
Mediastinum = space between the two lungs
Involvement of lymph nodes in the mediastinum or at the junction of the two main bronchi on the opposite side (contralateral), involvement of lymph nodes on the neck or above the clavicle on the same side or the opposite side
Depending on the degree of metastasis, further classification into 3 (non-small cell lung cancer) or 2 (small cell lung cancer) categories: M1a, M1b, (M1c)
T and N can be followed by an "X" instead of a number stand (TX, NX). This means that the respective aspect (T = tumor size, N = lymph node involvement) cannot be assessed.
The different stages of lung cancer
The TNM classification, as mentioned above, determines the stage of lung cancer. The following stages are distinguished, whereby the higher the stage, the more advanced the disease:
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Lung cancer stage 0
This stage corresponds to the classification Tis N0 Mo. This means: There is an early form of cancer that is still confined to its tissue of origin (carcinoma in situ). Lymph nodes are not affected, and there are no distant metastases yet.
Lung cancer stage I
This stage is divided into A and B:
Stage IA corresponds to a classification of T1 N0 M0. This means that the malignant lung tumor has a maximum diameter of three centimeters, is surrounded by lung tissue or lung pleura, and the main bronchus is not affected. There are also no lymph node involvement and no distant metastases present.
Depending on the more precise classification of tumor size – such as T1a(mi) or T1c – stage IA is further subdivided into IA1, IA2 and IA3.
At Stage IB the tumor has a classification of T2a N0 M0: it is more than three to a maximum of four centimeters in diameter, has neither affected lymph nodes nor spread to other organs or tissues.
Stage I lung cancer has the best prognosis and is often still curable.
Lung cancer stage II
Here, too, a distinction is made between A and B:
Stage IIA Includes lung tumors classified as T2b N0 M0: The tumor is more than four and not more than five centimeters in diameter. No lymph nodes are affected and no distant metastases are detectable.
To Stage IIB include tumors of size classification T1 (a to c) with lymph node involvement of type N1 but no distant metastases (M0).
Tumors of the size classification T2 (a or b) with lymph node involvement of the type N1 and without distant metastases (M0) are also assigned to this tumor stage.
The same applies to larger tumors classified as T3, when no lymph nodes are yet involved (N0) and no distant metastases have formed (M0).
Even in stage II, lung cancer can still be cured in some cases. However, treatment is already somewhat more complex, and the statistical life expectancy of patients is already lower than in stage I.
Lung cancer stage III
Stage III is further subdivided into A, B, and C:
In stage IIIA is present in tumors of the following classifications:
- T1 a to c N2 M0
- T2 a or b N2 M0
- T3 N1 M0
- T4 N0 M0
- T4 N1 M0
To stage IIIB include the following tumor classifications:
- T1 a to c N3 M0
- T2 a or b N3 M0
- T3 N2 M0
- T4 N2 M0
The Stage IIIC includes tumors of the following classification:
- T3 N3 M0
- T4 N3 M0
In simple terms, stage III lung cancer includes tumors of any size as soon as lymph nodes are affected (to varying degrees), but no distant metastases have yet formed. With regard to lymph node involvement, however, there is an exception: very large tumors are also assigned to this stage without lymph node involvement (T4 N0 M0) – more precisely, to stage IIIA.
In stage III, lung cancer is already so advanced that patients can only be cured in rare cases.
Lung cancer stage IV
Life expectancy and chances of cure are very low at this stage, because the disease is already very advanced: the tumor has already metastasized (M1). Tumor size and lymph node involvement are no longer important – they can vary (any T, any N). Depending on the extent of metastasis (M1 a to c), a distinction is made between the Stages IVA and IVB.
In any case, only palliative therapy is still possible for stage IV lung cancer – i.e., treatment aimed at alleviating symptoms and prolonging survival time.
The staging of lung cancer is based on tumor size, lymph node involvement and metastasis
Small cell lung cancer: alternative classification
Physicians distinguish between two major groups of lung cancer: small cell lung cancer and non-small cell lung cancer (see below). Both can be staged according to the TNM classification mentioned above and treated based on this classification.
However, the TNM system described above was primarily developed for the (much more common) non-small cell lung cancer. For small cell bronchial carcinoma, on the other hand, there are hardly any studies on tumor treatment based on the TNM system.
Instead, most of the available studies investigated treatment strategies based on a different classification of small cell lung cancer:
- "very limited disease": This category corresponds to the TNM classifications T1/2 with N0/1 and M0. Only about five percent of patients have this early stage of disease at the time of diagnosis.
- "limited disease"Corresponds to T3/4 with N0/1 and M0 or T1 to T4 with N2/N3 and M0. About 25 to 35 percent of all cases of small-cell bronchial carcinoma are discovered at this stage.
- "extensive disease"This includes all small cell lung cancers that have already formed distant metastases (M1) – regardless of tumor size (any T) and lymph node involvement (any N). In the vast majority of patients (60 to 70 percent), the tumor is already present at this advanced stage at the time of diagnosis.
Lung cancer: treatment
The therapy of a bronchial carcinoma is very complicated. It is individually adapted to each patient: Above all, it is based on the type and spread of lung cancer. However, the patient’s age and general health also play an important role in treatment planning.
If treatment is aimed at curing the lung cancer, it is referred to as a lung cancer cure curative therapy. Patients for whom a cure is no longer possible receive a palliative therapy. The aim is to prolong the patient’s life as much as possible and alleviate his or her symptoms.
Doctors from different specialties at a hospital consult with each other about the final treatment strategy. This includes, for example, radiologists, surgeons, internists, radiologists and pathologists. In regular meetings ("tumor boards"), they try to find the best lung cancer therapy for a patient.
There are essentially three therapeutic approaches, which are used individually or in combination:
- Surgery, to remove the tumor
- Chemotherapy with special drugs against fast-growing cells (such as cancer cells)
- Radiation of the tumor (radiotherapy)
In addition, there are some new therapeutic approaches, For example, with targeted drugs that directly attack the cancer cells. However, such new procedures are only possible in certain patients.
Lung cancer: surgery
There is usually only a real chance of a cure for lung cancer as long as it can be operated on. The surgeon tries to remove all the lung tissue affected by the cancer. He also cuts out a rim of healthy tissue. This is to ensure that no cancer cells are left behind. Depending on the spread of the bronchial carcinoma, one therefore removes either one or two lobes of the lung (lobectomy, bilobectomy) or even a whole lung (pneumonectomy).
In some cases, it would make sense to remove an entire lung. However, the patient’s poor state of health does not allow this to happen. Then the surgeon removes as much as necessary, but as little as possible.
During the operation, the surrounding lymph nodes (mediastinal lymph node dissection). This is done even if the preliminary examinations have given no indication of cancerous involvement of the lymph nodes. Often these are the first stop for a metastasis, which cannot be detected at the beginning.
Unfortunately, for many patients, there is no longer a chance that surgery can cure lung cancer: The tumor is already too far advanced at the time of diagnosis. In other patients, the tumor could in principle be operated on. However, the patient’s lung function is so poor that he couldn’t handle having parts of his lung removed. In the run-up to the operation, doctors therefore use special examinations to determine whether it makes sense to operate on a patient.
Lung cancer: chemotherapy
Like many other types of cancer, lung cancer can also be treated with chemotherapy. In this case, the patient receives drugs that inhibit the division of fast-growing cells – such as cancer cells. This can inhibit tumor growth. These agents are called chemotherapeutic agents or cytostatic agents.
Chemotherapy alone is not enough to cure lung cancer. This is why it is usually used in combination with other treatments. For example, it can be given prior to an operation to reduce the size of the tumor (neoadjuvant chemotherapy). Then the surgeon has to cut out less tissue afterwards.
In other cases, chemotherapy is given after surgery: It is designed to destroy any cancer cells still present in the body (adjuvant chemotherapy).
Chemotherapy for lung cancer usually consists of Several treatment cycles. There are therefore certain days on which the doctor administers the cytostatic drugs to the patient. There are breaks of two to three weeks between treatments. In most cases, the patient receives the drugs as an infusion through a vein. Sometimes, however, the preparations are also given in tablet form (orally).
In order to check the effect of the chemotherapy, the patient is regularly examined by means of computer tomography (CT). This is how doctors know if they may need to adjust chemotherapy. The physician can, for example, increase the dose of the active ingredient or prescribe another cytostatic drug.
Lung cancer: radiation
Another approach to lung cancer treatment is radiotherapy. Lung cancer patients usually receive radiation therapy in addition to another form of treatment. Similar to chemotherapy, radiotherapy can therefore be administered before or after surgery is performed. They are often used in addition to chemotherapy. This is then called Radiochemotherapy.
Some lung cancer patients also receive what is called a prophylactic cranial irradiation. This means: The skull is irradiated as a precautionary measure to prevent the development of brain metastases.
New therapeutic approaches for lung cancer
For several years, scientists have been researching new methods of (lung) cancer therapy:
At targeted therapies Drugs are administered that attack cancer cells directly (in contrast, cytostatic drugs = chemotherapeutic agents generally act against fast-growing cells, which include not only cancer cells but also hair root cells, for example). The targeted drugs interfere, for example, with mechanisms that control the growth of cancer cells. However, they are only effective if the cancer cells have suitable targets for the drug in question – and this is not the case for every lung cancer tumor.
Another new development is immunotherapies. Here, drugs are administered that help the immune system to fight the cancer more effectively. As with targeted therapies, this does not work for all patients. You can read more about this topic in the article Immunotherapy in cancer.
Some of these new therapies have already been approved for the treatment of advanced non-small cell lung cancer. In small-cell bronchial carcinoma, there is so far only one approval for an immunotherapeutic drug. Other new therapeutic approaches are still being tested in studies.
Other treatment measures
The above therapies are aimed directly at the primary tumor and any lung cancer metastases. In the course of the disease, however, various complaints and complications can arise that also need to be treated:
- Fluid between the lung and pleura (pleural effusion): it is aspirated through a cannula (pleural puncture). If the effusion recurs, a small tube can be inserted between the lung and the pleura to drain off the fluid. It remains in the body longer (thoracic drainage).
- Bleeding in the bronchiSuch tumor-related hemorrhages can be stopped, for example, by specifically closing the blood vessel in question, for example during a bronchoscopy.
- Occlusion of blood vessels or airways by the tumorIf the tumor has spread to the blood vessels or. If the airways are blocked, they can be opened up again by inserting a stent (stabilizing tube). Or the tumor tissue is removed from the affected area, for example with a laser.
- Tumor painAdvanced lung cancer can cause severe pain. The patient then receives a suitable pain therapy, for example painkillers in tablet or injection form. In the case of painful bone metastases, radiation can provide relief.
- Respiratory distressIt can be alleviated with medication and the administration of oxygen. Special breathing techniques and the correct positioning of the patient are also helpful.
- Severe weight lossAffected patients may need to be artificially fed.
- Side effects of chemotherapy such as nausea and anemia: they can be treated with suitable drugs.
In addition to treatment of the physical symptoms, it is also very important that the patient mental well cared for becomes. Psychologists, social services and self-help groups help patients cope with the disease. This increases the patient’s quality of life. Relatives can and should also be included in the therapy concepts.
Lung cancer: "Concentrate fully on the treatment"
Three questions for
Why is lung cancer often detected so late?
In the early stages, lung cancer is often asymptomatic or nonspecific. For example, you may have a persistent cough or feel listless. Later, complications such as pneumonia can occur – but by then lung cancer is usually already in an advanced stage.
How can I support the treatment of lung cancer?
Lung cancer is an aggressive disease that very often leads to death. This process can only be stopped if you, as the patient, put diagnosis and therapy first. This means: Avoid delays, for example, due to weekend activities, vacations or stays in rehabilitation clinics. This can have fatal consequences. Concentrate fully on your treatment.
Do you have a special tip for those affected?
The therapy of lung cancer has made significant progress in recent years. Modern molecular methods enable "targeted therapies" – i.e. cancer therapy that is directed as far as possible only against the cancer cells and is therefore better tolerated and more effective. Find a practice or clinic that uses these modern methods in diagnostics and therapy.
Dr. Gahn is head physician of oncology at the Paracelsus Clinic in Henstedt-Ulzberg, specializing in hematology and internal medicine oncology.
Small cell lung cancer
The treatment of lung cancer is influenced by what type of tumor it is. Depending on which cells of the lung tissue become cancer cells, physicians distinguish between two large groups of lung cancer: One of them is small cell lung cancer (SCLC).
This form of lung cancer grows very quickly and forms early metastases in other parts of the body. At the time of diagnosis, the disease is therefore usually already far advanced.
The most important treatment method is chemotherapy. Some patients receive additional radiation or immunotherapy. If the tumor is still very small, surgery can still be useful.
You can read more about the development, treatment and prognosis of this form of lung cancer in the article SCLC: Small cell lung cancer.
Non-small cell lung cancer
Non-small-cell lung cancer is the most common form of lung cancer. It is often abbreviated as NSCLC ("non small cell lung cancer"). Strictly speaking, the term "non-small cell lung cancer" covers Different tumor types. These include adenocarcinoma and squamous cell carcinoma.
The following applies to all non-small cell lung cancers: they grow more slowly than small cell lung cancers and only form metastases at a later stage. For this they do not respond so well to chemotherapy.
The treatment of choice is therefore surgery if possible: the surgeon attempts to remove the tumor completely. In more advanced stages, radiation and/or chemotherapy is usually chosen (in addition to or as an alternative to surgery). In certain patients, new therapeutic approaches (targeted therapies, immunotherapy) can also be considered.
You can read more about this widespread form of lung cancer in the article NSCLC: Non-small cell lung cancer.
Lung cancer: causes and risk factors
Lung cancer develops when – probably due to a genetic change – Cells in the bronchial system begin to grow uncontrollably. Physicians refer to the large and small airways of the lungs (bronchi and bronchioles) as the bronchial system. The medical term for lung cancer is therefore bronchial carcinoma. The word "carcinoma stands for a malignant tumor made of so-called epithelial cells. They form the covering tissue that lines the airways.
The uncontrolled growing cells multiply very fast. In the process, they increasingly displace healthy lung tissue. In addition, the cancer cells can spread via blood and lymph channels and form a daughter tumor elsewhere. Such metastases are called lung cancer metastases.
Lung cancer metastases should not be confused with lung metastases: These are daughter tumors in the lungs that originate from cancerous tumors elsewhere in the body. For example, colorectal cancer and renal cell cancer often cause lung metastases.
The genetic changes that lead to the development of lung cancer can occur quite randomly as part of normal cell division (without any identifiable trigger) or be triggered by risk factors.
Smoking: The most important risk factor
The most important risk factor for uncontrolled and malignant cell growth in the lungs is Smoking. Around 90 percent of all men with lung cancer have actively smoked or still do so. In women, this applies to at least 60 percent of patients. The higher the risk of developing the disease:
- the longer someone smokes
- the earlier one started smoking
- The more you smoke
- the more one smokes passively
Passive smoking also increases the risk of lung cancer!
At present, physicians assume that of all these factors, the Duration of smoking The risk of lung cancer is most strongly increased in women.
However, the Extent of tobacco use plays a major role: physicians measure a patient’s previous cigarette consumption in the unit Pack years (pack years). If someone smokes a pack of cigarettes every day for a year, this is called a "pack year" counted. If someone smokes one pack a day for ten years or two packs a day for five years, that’s ten pack-years each. The following applies: the more pack years, the higher the risk of lung cancer.
In addition to the number of cigarettes smoked, the Type of smoking plays a role: the more smoke you inhale, the worse it is for your lungs. Also having an influence on the risk of lung cancer is the Cigarette typeStrong or even filterless cigarettes are particularly harmful.
To protect yourself from lung cancer, you should therefore Stop smoking! The lungs can recover, and the sooner you stop smoking (i.e., the shorter your smoking history), the better. Then your risk of lung cancer drops again.
For example, two years after quitting smoking, the risk of lung cancer in male ex-smokers is only 7.5 times higher than in men who never smoked. The risk of bronchial carcinoma also decreases in women when they stop smoking, but it is still twice as high as in lifelong non-smokers.
No matter how long and how much you have smoked, it is never too late to stop!
Other risk factors for lung cancer
Aside from smoking, there are other factors that can increase the risk of lung cancer:
- Air pollutionAir pollutants increase the risk of lung cancer, especially diesel soot and particulate matter.
- Other pollutants: Asbestos, arsenic and arsenic compounds have long been known to cause cancer. Other substances such as quartz dust, man-made mineral fibers (such as rock wool), polycyclic aromatic hydrocarbons (PAHs), dichlorodimethyl ether, beryllium and cadmium also increase the risk of lung cancer (and other cancers).
- ionizing radiationRadon is a naturally occurring radioactive gas that is carcinogenic and is increasingly found in some places. It accumulates especially in the basement and first floor of buildings. Exposure to radiation also exists, for example, for flight personnel (cosmic radiation) and during X-ray examinations (X-rays).
- Genetic predispositionTo some extent, lung cancer appears to be hereditary. However, it is still largely unclear how significant genetic factors are and in which patients they actually play a role in the development of lung cancer. Probably play a role especially in very young patients. For example, genetic predisposition could make affected individuals more susceptible to lung-damaging influences (such as smoking).
- Infections and injuries: Scars in the lung tissue, such as those that occur as a result of infections (e.g.B. tuberculosis) or injuries increase the risk of cancer. It is also being discussed whether the AIDS virus HIV and human papillomaviruses (HPV) promote the development of lung cancer – either directly or via another connection.
- Low vitamin dietEating few fruits and vegetables apparently increases the risk of lung cancer. This is especially true for smokers. However, taking vitamin supplements is not an alternative: especially in smokers, such supplements seem to further increase the risk of bronchial cancer.
If several of these factors are present at the same time, the probabilities for lung cancer not only add up: rather, the risk of disease increases many times over. For example, high levels of air pollution increase the risk of lung cancer much more in smokers than in non-smokers.
Sometimes not a cause of lung cancer find. This is referred to as an idiopathic disease. Of all types of lung cancer, this applies most frequently to adenocarcinoma. This is a form of non-small cell bronchial carcinoma.
Lung cancer: examinations and diagnosis
The lung cancer diagnosis is often made at a late stage. Symptoms such as persistent cough, chest pain and shortness of breath are often not recognized as possible signs of lung cancer, especially by smokers – most patients simply blame smoking. Others suspect a severe cold, bronchitis, or pneumonia is behind the symptoms. Only medical examinations then reveal the suspicion of bronchial carcinoma.
The first point of contact for possible symptoms of lung cancer is the general practitioner. If necessary, he or she will refer the patient to specialists, such as a radiologist, pulmonologist or oncologist. In order to make a diagnosis of lung cancer, a medical history, a physical examination and various instrumental examinations are necessary.
Medical history and physical examination
First, the physician discusses the patient’s medical history with the patient Medical history (Anamnesis): He has the occurring complaints such as shortness of breath or chest pain described to him in detail. It also inquires about risk factors for lung cancer. For example, he asks whether the patient smokes or works with materials such as asbestos or arsenic compounds.
Information on possible previous or underlying diseases such as COPD or chronic bronchitis is also important for the diagnosis of lung cancer. Patients should also tell the doctor if there have been previous cases of lung cancer in their family.
After the anamnesis interview, the doctor will carefully physically examine. Among other things, he taps and listens to the patient’s lungs and measures blood pressure and pulse. The examination may provide possible clues to the cause of the symptoms. In addition, the physician can better assess the patient’s general health condition.
Using an X-ray of the chest (chest X-ray), the physician can already detect changes in the lung tissue. If this results in a suspicion of lung cancer, the next step is a computed tomography (CT) scan.
The doctor examines the patient’s chest in two planes, i.e. from the front and from the side.
Computer tomography (CT)
Computed tomography provides detailed cross-sectional images of the lungs in high resolution. This is possible with the help of X-rays, which are much higher dosed than in a normal X-ray examination. In addition, the patient is administered a contrast medium in advance. This makes it easier to visualize the various tissue structures.
The doctor can assess suspicious lung changes better with the help of CT than with the help of X-rays. This can confirm the suspicion of lung cancer.
Examination of tissue samples (biopsy)
To be sure whether a conspicuous spot in the lung tissue is actually a bronchial carcinoma, you need to remove a small piece of tissue and examine it microscopically. Depending on the location of the suspicious area, different methods are used for this:
In the Pulmonary endoscopy (bronchoscopy), a tube-shaped instrument with a tiny camera and a light source at the tip (endoscope) is inserted through the mouth or nose into the patient’s trachea and further into the bronchial tubes. This allows the physician to view the lungs from the inside. In this way, a tumor can often already be detected visually. In addition, the doctor can take tissue samples and secretions from the lungs through the endoscope using fine instruments for more detailed analysis.
If it is difficult or impossible to reach the suspicious tissue through the bronchial tubes, the doctor performs what is known as a "bronchoscopy" transthoracic needle aspiration by the physician: This involves inserting a very fine needle between the ribs from the outside. Under CT control, the needle tip is advanced to the suspicious lung area. It then sucks (aspirates) a bit of tissue through the needle.
In some patients, neither bronchoscopy nor transthoracic needle aspiration is possible, or both examinations do not provide clear results. Then a Surgical biopsy Either the surgeon opens the thorax with a larger incision (thoracotomy) and takes a sample of the suspicious tissue. Or he makes small incisions in the chest through which he inserts a small camera and fine instruments to remove tissue (video-assisted thoracoscopy, VATS).
Regardless of how the tissue sample is taken, it is examined under a microscope. As a rule, it is possible to tell from just a few cells whether lung cancer is present and, if so, what type of tumor (cytological diagnostics). Only in special cases it is necessary to examine larger sections of tissue(histological diagnosis).
Examination of tumor spread (staging)
Once the diagnosis of lung cancer has been made, the next step is to examine how it has spread in the body. This stage of the examination is referred to by physicians as staging. for staging). It is only through such staging that bronchial carcinoma can be classified according to TNM classification.
Staging involves three steps:
- Examination of tumor size (T-status)
- examination of the lymph node involvement (N-status)
- Search for metastases (M-status)
Examination of the primary tumor (T-status)
First, examine how large the tumor is from which the lung cancer originates (primary tumor). For this purpose, the patient is given a contrast medium before his or her chest and upper abdomen are scanned by means of Computed tomography (CT) investigated. The contrast agent accumulates for a short time, especially in the tumor tissue, causing a mark on the CT image. This allows the doctor to assess the extent of the primary tumor.
If the CT scan is not conclusive enough, further procedures are used. This can be done, for example, by Ultrasound examination of the chest (thoracic sonography) or a Magnetic resonance imaging (MRT) – also called herniated magnetic resonance imaging – can be a major problem.
Examination of lymph node involvement (N-status)
In order to be able to plan the therapy optimally, the doctor must know whether the lung cancer has already affected the lymph nodes. Here, too, the examination by computed tomography (CT) helps. A special technique is often used in this process: the so-called FDG-PET/CT. This is a combination of positron emission tomography (PET) and CT:
Positron emission tomography (PET) is a nuclear medical examination. The lying patient is first injected with a tiny amount of a radioactive substance into a vein. With the FDG-PET/CT we are talking about FDG. This is a radioactively labeled simple sugar (fluorodeoxyglucose). It is distributed in the body and accumulates particularly in tissues with increased metabolic activity, for example in cancer tissue. During this time, the patient must remain as still as possible. After about 45 (to 90) minutes, the PET/CT scan is performed to image the distribution of FDG in the body:
The PET camera can show very well the different metabolic activity in the various tissues. Particularly active areas (such as cancer cells in lymph nodes or metastases) "glow" regular on the PET image. Bones, organs and other structures of the body can PET but not so well represent. This is done by the almost simultaneously performed computed tomography (CT) – PET camera and CT are combined in one device. It allows a very precise visualization of the different anatomical structures. In combination with the precise imaging of metabolic activity, this allows the precise localization of cancer foci.
FDG-PET/CT can be used to very accurately visualize metastases from lung cancer in lymph nodes and even more distant organs and tissues. To be sure, the doctor can take a tissue sample of the suspicious areas and examine it for cancer cells (biopsy).
Search for metastases (M-status)
Cancer cells spreading to other organs is a major problem in bronchial carcinoma. Metastases form particularly often in the liver and brain, as well as in the bones and adrenal glands. In principle, however, any body structure can be affected by the cancer cells. Lung cancer that has already spread is considered incurable.
With the special examination described above FDG-PET/CT metastases can be detected anywhere in the body. In order to detect possible metastases in the brain, the skull is also examined by means of a CT scan Magnetic resonance imaging (MRI) examines.
FDG-PET/CT is not possible in some patients. The alternative is then a Computed tomography or Ultrasound examination of the trunk and additionally a so-called Skeletal scintigraphy (bone scintigraphy). Also Full body MRI-images are possible.
Other testing methods may also be used in staging, such as an endoscopic examination of the pleural cavity (thoracoscopy).
There are no blood tests that can help diagnose lung cancer with certainty. However, one can be so-called Tumor markers in the blood determine. These are substances whose blood levels may be elevated in cresber disease. The tumor markers are produced either by the cancer cells themselves or by the body in response to the cancer. In lung cancer, for example, the tumor markers neuron-specific enolase (NSE) and CYFRA 21-1 may be elevated.
However, the measurement of tumor markers plays only a minor role in the diagnosis of lung cancer and is not routinely recommended here. The measured values alone are not conclusive – tumor markers are not detectable in all patients and are also sometimes found in the blood of healthy people.
Tumor markers are more relevant for assessing the course of the disease: the concentration of tumor markers in the blood can give the physician an indication of how quickly the tumor is growing or whether cancer cells are reappearing after treatment.