Lung cancer (bronchial carcinoma)

Lung cancer refers to a degeneration of the tissue in different areas of the lungs. Different types are distinguished, which include cancer of the actual lung tissue, as well as rare cancers such as mesothelion (cancer of the lung pleura).

One can distinguish between different types of bronchial carcinoma. Small cell lung carcinoma is considered particularly dangerous, as it is extremely fast growing and spreads rapidly throughout the body. Slow-growing lung carcinomas include non-small cell squamous cell carcinoma, adenocarcinoma, and large cell carcinoma. These carcinomas have a better prognosis overall.

There are approximately 52 new cases per year per 100,000 people in Europe. Men are three times more likely to be affected by the disease than women. However, statistics show that since the early 1990s, the number of new cases among women has increased threefold, while the number of men affected has steadily declined.

Lung cancer can rarely be cured, which is why it is the most common cause of cancer-related death in men and the third most common cause of cancer-related death in women. The death statistics behave controversially in men and women: in men it is slightly decreasing, while in women it is increasing.

Cancer is primarily a disease of advanced age. Most new cases occur in the 55 to 60 age group. Only five percent of those with the disease are younger than 40.

Smoking is considered to be the main cause of lung cancer. It is believed that about 85 percent of patients who die of lung cancer are smokers. According to the latest statistics, the trend is that more and more men are giving up smoking, but more and more women are starting.

The trigger for mesothelioma, which is very rare, is asbestos. According to estimates, around 500,000 to 1,000,000 workers in Germany have a workplace that is at risk from asbestos. This type of tumour takes around 15 to 50 years to develop, which is why an increase in the incidence of the disease is expected around the year 2020.

The reason for lung cancer is smoking. However, in some cases, pollutants in the workplace or hereditary factors may also be responsible for its development. Lung cancer usually develops as a result of external factors:

• Smoking: About 85 percent of people in whom lung cancer emerges as a cause of death are smokers. The risk of developing lung cancer increases by 30 times if smoking was started in adolescence.
• Secondhand Smoking: Secondhand smoke increases the risk of lung cancer by a factor of 1.3 to 2.0, and if the duration of exposure increases, the risk of disease also increases.
• High levels of air pollution can also lead to a slight increase in risk (by a factor of about 1.5). The decisive factor, however, appears to be diesel soot. It increases the risk especially in smokers. In addition, buildings with high radon exposure may have an increased concentration of this radioactive gas. Consequently, the risk of lung cancer also increases.
• Familial exposure: If one parent suffers from bronchial carcinoma, the person has a two to three times higher risk of developing the disease.
• Substances such as asbestos, quartz dust, as well as arsenic compounds pose a risk for bronchial carcinoma and mesothelioma.
• Lung scars, such as those caused by tuberculosis or lung surgery, also increase the risk of lung cancer.

At the beginning of the disease are hardly noticeable symptoms. The first sign may be a cough, for example, but this can also indicate other diseases such as chronic bronchitis.

In some cases, lung cancer can only be detected if the cough does not improve despite antibiotic treatment, or if blood is found in the sputum. However, this is already a symptom of the disease at an advanced stage. Only a negligible proportion of lung cancer cases are diagnosed by routine examination of the lungs.

Other typical complaints that manifest themselves in lung cancer are:

• Loss of appetite, fatigue, weight loss, shortness of breath, or constantly slightly elevated body temperature.
• Lung inflammations that show no improvement after treatment (also known as therapy-resistant lung inflammations). In people over 40, they can be a sign of lung cancer.
• Paralysis, as well as severe pain and a general loss of strength.
• Prolonged coughing episodes that last for a period of more than three weeks. This symptom most often occurs in smokers, for whom lung medications often have a worse effect.
• In some cases, symptoms atypical of lung cancer may also present. These include brain or spinal cord injuries, and hormonal imbalances (such as Cushing's syndrome). These features are due to hormonal activity of the tumor (paraneoplastic syndromes).

If there is a suspicion that the patient has lung cancer, the first step is an X-ray examination of the lungs. After that, a computer tomography (CT) is usually performed and the cough expectoration (sputum) is examined for cancer cells.

An examination of the blood can detect so-called tumour markers. If certain markers are elevated, this may indicate bronchial carcinoma.

If the result of these examinations is positive, a bronchoscopy (endoscopic examination of the bronchial tubes) is also performed. In the course of this examination, tissue samples (biopsy) and cell material are sometimes taken for analysis. This allows a definite diagnosis to be made. A disadvantage is that only tumours that are located close to the bronchial system can be detected with the help of a bronchoscopy.

If a definite diagnosis cannot be made, it is necessary in rare cases to perform an operation (diagnostic thoracotomy). With the help of this method, tissue samples can be taken, which can be examined histopathologically for cancer cells.

If a definite diagnosis of lung cancer is made from these examinations, further examinations must be carried out to find any metastases. These examinations include:

• Computed tomography (CT)
• Magnetic resonance imaging (MRT)
• Ultrasound examination (sonography)
• Skeletal scintigraphy (bone scintigraphy)
• Positron emission tomography (PET)
• Mediastinoscopy (examination of the chest)

The treatment of lung cancer depends on the type of cancer (non-small cell or small cell bronchial carcinoma) and the stage the tumour is already in. Non-small cell lung cancer is usually treated with surgery followed by radiation therapy and chemotherapy. Small cell lung cancer is very fast growing and forms metastases in the early stages. For this reason, surgery cannot be performed in all cases. Therefore, a combination of chemotherapy and radiation therapy is often used in this case.

Surgery:

In the case that metastasis has not yet occurred, or only a lymph node close to the tumor is affected, the carcinoma is operated on. The cancerous tumour is removed together with a part of the healthy lung. Removing the healthy tissue ensures that no cancer cells remain in the tissue. In some cases, surgery is followed by chemotherapy.

Chemotherapy/Radiation Therapy:

If the bronchial cancer is advanced, either radiation therapy or chemotherapy is used. In many cases, a combination of the two methods is also used (multimodal therapy). Occasionally, therapy may begin before surgery. Chemotherapy can be given in the form of capsules or tablets, but also by infusion or injection.

Therapy with antibodies (target therapy):

Antibodies can have the effect of blocking the transmission of growth impulses inside the cancer cell. Some antibodies are still in the testing phase, while others are already being used in lung cancer. For the treatment of non-small cell lung cancer, for example, the antibody Erlotinib has been in use in Germany since the end of 2005 and has the effect of inhibiting tumour cell growth.

Another group of antibodies inhibits the growth of blood vessels that are responsible for supplying the tumour (angiogenesis inhibitors). One angiogenesis inhibitor, for example, is bevacizumab, which has been used throughout the EU for the treatment of lung cancer since 2007.

In general, mesotheliomas are operable, but in most cases the tumour has already spread too far, making surgery impossible.

If there is no hope of curing the cancer, the main focus is on alleviating the symptoms. These include, above all, shortness of breath, which is caused by the tumour growing into the windpipe.

The shortness of breath can be prevented by inserting a metal tube (stent) into the trachea to keep it open. Another option is to reduce the tumor mass by laser or radiation from the inside (endoluminal brachytherapy).

In many cases, lung cancer patients suffer from pain-causing bone metastases. These can be alleviated with special drugs (biphosphates) or strong painkillers.

The chances of recovery from lung cancer are usually not positive and depend on the stage and type of cancer. The five-year survival prognosis is only 15 percent. In general, it can be said that the chances of survival with small cell carcinoma are significantly lower than with non-small cell carcinoma. On the other hand, the prognosis is significantly better if the cancer is detected at an early stage.

In many cases, however, doctors are able to reduce the growth of the lung cancer thanks to modern therapy methods (mostly chemotherapy and radiation) and thus bring about a significant prolongation of life.

If the lung cancer is operable, there is a chance of a complete recovery. Sometimes the tumour can be removed with a relatively minor operation. This is especially the case if the tumour is located far outside the lung (in the area of the rib cage). The affected lobe of the lung is then removed.

The most effective way to prevent lung cancer is to stop smoking.

The more cigarettes consumed, the higher the risk of developing lung cancer: daily consumption of one to 14 cigarettes increases the risk by a factor of 8, while consumption of 25 cigarettes already increases the risk by a factor of 25. Stopping smoking leads to a significant reduction in the risk of contracting the disease. The risk goes down within a few years, but still remains higher than for people who have never smoked. People who stop smoking at the age of 30 have only a slightly increased risk of developing lung cancer in the long term.

A high intake of fruit and vegetables can have a positive effect on the health of smokers and reduce the risk of disease, but not to the extent that it cancels out the risk of smoking. It is important to take vitamins and trace elements in their natural form and not through supplements. According to the study, taking high doses of beta-carotene in the form of tablets is actually more likely to lead to a deterioration in the health of smokers.

If there is a risk of lung cancer-causing substances (asbestos, quartz dusts, radioactive radiation) at the workplace, the Occupational Health and Safety Act should be observed (wearing respirators, gloves or similar).