Lung cancer (bronchial carcinoma)

Brief overview

  • Symptoms: Initially often no symptoms or only nonspecific symptoms (such as persistent cough, chest pain, fatigue). Later, e.g., shortness of breath, low-grade fever, severe weight loss, bloody sputum.
  • Main forms of lung cancer: the most common is non-small cell lung cancer (with subgroups). Less common but more aggressive is small cell bronchial carcinoma.
  • Causes: Primarily smoking. Other risk factors include asbestos, arsenic compounds, radon, high levels of airborne pollutants, and a diet low in vitamins.
  • Examinations: X-ray, 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, radiotherapy, chemotherapy, possibly other methods.
  • Prognosis: Lung cancer is usually detected late and is therefore rarely curable.

Lung cancer: signs (symptoms)

More pronounced signs of lung cancer occur in the advanced stage. 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 are headaches, nausea, impaired vision and balance, or even paralysis. If the cancer cells have affected the bones, osteoarthritis-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 cancer, develops when cells degenerate. In this case, it is cells of the lung tissue. The degenerated cells multiply uncontrollably and displace healthy tissue around them. Later, individual cancer cells can spread throughout the body via the blood and lymph vessels. They then often form a daughter tumor (metastasis) elsewhere.

Lung cancer: TNM classification

The TNM scheme is an international system to describe the spread of a tumor. It stands for:

  • “T” stands for the size of the tumor
  • “N” for the involvement of lymph nodes (Nodi lymphatici)
  • “M” for the presence of metastases

For each of these three categories, one assigns 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 provide a rough overview:

TNM

Tumor character at diagnosis

Notes

Tis

Carcinoma in situ ( tumor in situ )

Early form of cancer: the tumor is still confined to its origin, i.e. has not yet grown into surrounding tissue.

T1

The tumor is 3 cm max in largest diameter, surrounded by lung tissue or lung pleura, and the main bronchus is not involved.

The main bronchi are the first branches of the trachea in the lungs.

T1 can be further specified and is therefore subdivided into:

T2

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 due to the tumor the lung is partially collapsed (atelectasis) or partially or totally inflamed

Further breakdown into:

T3

T4

The largest diameter of the tumor is > 7 cm OR other organs are affected (e.g., diaphragm, heart, blood vessels, trachea, esophagus, vertebral body) OR there is an additional tumor nodule in another lung lobe

N0

no lymph node involvement

N1

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 = point of entry of pulmonary vessels and main bronchi into the lung

N2

Involvement of lymph nodes in the mediastinum and/or at the outlet of the two main bronchi of the same side

Mediastinum = space between the two lungs

N3

Involvement of lymph nodes in the mediastinum or at the outlet of the two main bronchi on the opposite side (contralateral), involvement of lymph nodes in the neck or above the clavicle on the same side or the opposite side

M0

No distant metastasis(s)

M1

Distant metastasis(s) present

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 (TX, NX). This means that the respective aspect (T = tumor size, N = lymph node involvement) cannot be assessed.

The various lung cr

Lung cancer stage 0

This stage corresponds to the classification Tis N0 Mo, which means that 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 is also no lymph node involvement and no distant metastases.

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.

In 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 not affected lymph nodes or spread to other organs or tissues.

Stage I lung cancer has the best prognosis and is often still curable.

Stage II lung cancer

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 no more than five centimeters in diameter. No lymph nodes are affected and no distant metastases are detectable.

Tumors of size classification T2 (a or b) with lymph node involvement of type N1 and without distant metastases (M0) are also assigned to this tumor stage.

The same applies to larger tumors of the classification T3, if no lymph nodes have been affected (N0) and no distant metastases have formed (M0).

Even in stage II, lung cancer is still curable in some cases. However, treatment is somewhat more complex, and the statistical life expectancy of patients is already lower than in stage I.

Stage III lung cancer

Stage III is further subdivided into A, B and C:

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

Stage IIIB includes the following tumor classifications:

  • T1 a to c N3 M0
  • T2 a or b N3 M0
  • T3 N2 M0
  • T4 N2 M0

Stage IIIC includes tumors of the following classification:

  • T3 N3 M0
  • T4 N3 M0

In simple terms, lung cancer stage III 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 one 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.

Life expectancy and chances of cure are very low at this stage because the disease is already very advanced here: the tumor has already metastasized (M1). Tumor size and lymph node involvement are then 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 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.

Small cell lung cancer: alternative classification

Medical experts distinguish between two major groups of lung cancer: small cell bronchial carcinoma and non-small cell bronchial carcinoma (see below). Both can be staged according to the TNM classification mentioned above and treated based on this classification.

However, the TNM system outlined above was primarily developed for non-small cell bronchial carcinoma (which is much more common). For small cell lung cancer, 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 bronchial carcinoma.

  • “limited disease”: equivalent to T3/4 with N0/1 and M0 or T1 to T4 with N2/N3 and M0. Approximately 25 to 35 percent of all cases of small cell lung cancer are detected at this stage.
  • “extensive disease”: this includes all small cell bronchial carcinomas 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 at this advanced stage at the time of diagnosis.

Lung cancer: Treatment

The treatment of bronchial carcinoma is very complicated. It is individually adapted to each patient: First of all, it depends 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 curative therapy. Patients for whom a cure is no longer possible receive palliative therapy. The aim is to prolong the patient’s life as much as possible and alleviate his or her symptoms.

There are three main therapeutic approaches that are used individually or in combination:

  • Surgery to remove the tumor
  • Chemotherapy with special drugs against fast-growing cells (such as cancer cells)
  • Irradiation 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

Lung cancer usually only has a real chance of being cured if it can be operated on. In this operation, the surgeon tries to remove all of the lung tissue affected by the cancer. He also cuts out a margin of healthy tissue. In this way, he wants to make sure that no cancer cells remain. Depending on the spread of the bronchial carcinoma, one therefore removes either one or two lobes of the lung (lobectomy, bilobectomy) or even an entire lung (pneumonectomy).

In some cases, it would make sense to take out an entire lung. However, the patient’s poor health does not allow this. Then the surgeon removes as much as necessary, but as little as possible.

Unfortunately, in many patients there is no longer any prospect of surgery curing the lung cancer: The tumor is already too advanced at the time of diagnosis. In other patients, the tumor would in principle be operable. However, the patient’s lung function is so poor that he or she would not tolerate having parts of the lung removed. In the run-up, doctors therefore use special examinations to check whether surgery is appropriate for a patient.

Lung cancer: chemotherapy

Like many other types of cancer, lung cancer can also be treated with chemotherapy. The patient is given drugs that inhibit the division of fast-growing cells, such as cancer cells. This can inhibit tumor growth. These agents are called chemotherapeutics or cytostatics.

Chemotherapy alone is not enough to cure lung cancer. It is therefore usually used in combination with other treatments. For example, it can be given before surgery to reduce the size of the tumor (neoadjuvant chemotherapy). The surgeon then has to cut out less tissue afterwards.

In other cases, chemotherapy is given after surgery: It is intended to destroy any cancer cells still present in the body (adjuvant chemotherapy).

To check the effect of the chemotherapy, the patient is regularly examined by means of computer tomography (CT). In this way, the doctor can see whether he or she may need to adjust the chemotherapy. He can, for example, increase the dose of active ingredient or prescribe another cytostatic drug.

Lung cancer: radiation

Another approach to lung cancer treatment is radiation. Lung cancer patients usually receive radiation therapy in addition to another form of treatment. Similar to chemotherapy, radiation can be given before or after surgery, for example. It is also often used in addition to chemotherapy. This is called radiochemotherapy.

Some lung cancer patients also receive what is known as prophylactic cranial irradiation. This means that the skull is irradiated as a precaution to prevent the development of brain metastases.

New therapeutic approaches for lung cancer

For some years now, scientists have been researching new methods of (lung) cancer therapy:

Another new development is immunotherapies. Here, drugs are administered that help the immune system fight the cancer more effectively. As with targeted therapies, however, this does not work for all patients. You can read more about this topic in the article Immunotherapy for cancer.

Some of these new therapies are already approved to treat advanced-stage non-small cell lung cancer. In small cell bronchial carcinoma, there is only one approval for an immunotherapeutic drug so far. Other new therapeutic approaches are still being tested in trials.

Other treatment measures

The above therapies directly target the primary tumor and any lung cancer metastases. However, as the disease progresses, various symptoms and complications may 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 runs back up, a small tube can be inserted between the lung and pleura to drain the fluid. It remains in the body longer (chest drainage).
  • Bleeding in the bronchial tubes: Such tumor-related bleeding can be stopped, for example, by specifically closing the blood vessel in question, for example during a bronchoscopy.
  • Tumor pain: Advanced lung cancer can cause severe pain. The patient then receives appropriate pain therapy, for example painkillers as tablets or injections. In the case of painful bone metastases, radiation can provide relief.
  • Shortness of breath: This can be alleviated with medication and the administration of oxygen. Special breathing techniques and correct positioning of the patient are also helpful.
  • Severe weight loss: Affected patients may need to be artificially fed.
  • Side effects of chemotherapy such as nausea and anemia: These can be treated with suitable medication.

In addition to the treatment of physical complaints, it is also very important that the patient receives good mental care. Psychologists, social services and self-help groups help with coping with the disease. This improves the patient’s quality of life. The relatives can and should also be included in the therapy concepts.

Small-cell bronchial carcinoma

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 major groups of lung cancer: one is small cell lung cancer (SCLC).

The most important treatment method is chemotherapy. Some patients also receive radiation or immunotherapy. If the tumor is still very small, surgery may also 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 various types of tumors. These include adenocarcinoma and squamous cell carcinoma.

The following applies to all non-small cell lung carcinomas: they grow more slowly than small cell lung cancer and only form metastases later. On the other hand, they do not respond as well to chemotherapy.

The treatment of choice is therefore surgery, if possible: the surgeon tries to remove the tumor completely. In more advanced stages, radiation therapy and/or chemotherapy are usually chosen (in addition to or as an alternative to surgery). In certain patients, new therapeutic approaches (targeted therapies, immunotherapy) may also be considered.

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. Doctors 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 consisting of so-called epithelial cells. They form the covering tissue that lines the airways.

The uncontrolled growing cells multiply very quickly. 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 may occur quite accidentally as part of normal cell division (with no apparent trigger) or may be triggered by risk factors.

Smoking: The most important risk factor

  • the longer someone smokes
  • the earlier one started smoking
  • the more one smokes
  • the more one smokes passively

Passive smoking also increases the risk of lung cancer!

Currently, physicians assume that of all these factors, the duration of smoking increases the risk of lung cancer the most.

However, the extent of tobacco consumption also plays a major role: physicians measure a patient’s previous cigarette consumption in units of pack years. If someone smokes a pack of cigarettes every day for a year, this is counted as “one pack year.” If someone smokes one pack a day for ten years or two packs a day for five years, this is counted as ten pack years. The more pack-years, the higher the risk of lung cancer.

In addition to the number of cigarettes smoked, the type of smoking also plays a role: the more smoke you inhale, the worse it is for your lungs. The type of cigarette also has an influence on the risk of lung cancer: strong or even filterless cigarettes are particularly harmful.

So to protect yourself from lung cancer, you should stop smoking! The lungs can then also recover, and the earlier you stop smoking (i.e. the shorter your smoking career), the better. Then your risk of lung cancer decreases again.