What is lung cancer?
Lungs tumors are malignant in over 90 percent of cases. They can basically develop in all lung sections, but most often they are found in the upper part of the lung. This region is more ventilated during respiration and thus comes increasingly in contact with harmful substances.
Lung cancer is one of the most common malignancies in Germany with about 40,000 deaths per year and is rarely curable. According to the Federal Statistical Office, 28,652 men and 10,634 women died of bronchogenic carcinoma in 2003. Lung cancer is the most common cause of death in men and the third most common cause of cancer death among women. Due to changing smoking habits, the number of deaths among women is currently on the rise, with a slight decline in men since the mid-1980s.
lung cancer causes
Today, lung cancer is based on a multi-stage concept: on the first level, there is contact with a carcinogenic substance, such as tobacco smoke or asbestos (see also Risk Factors ). The second stage is caused by the carcinogen damage to the genetic material (so-called mutations) of the cells in the lower respiratory tract (bronchi) or in the lungs ( alveoli, ie alveoli ). On the third stage comes – after a certain period of rest ( latency) of up to 40 years or even earlier – to a degenerate, unchecked growth of the damaged cells. This is how malignant tumors and cancer develop. Cigarette smoking is both the most important trigger and the most important driver of the disease. Basically, cancer always seems to always start from one cell.
lung cancer risk factors
Many different factors can work together in the development of lung cancer. First and foremost, harmful substances in the respiratory air cause the mucosal cells of the bronchi to gradually transform into cancer cells. By far the most important risk factor for lung cancer is smoking. But pollutants at work and in the air are also considered risk factors. Furthermore, diet, infections and occupational disease (eg silicosis ) and possibly also hereditary preload play a role. Although there is no clear evidence for the latter, one can observe a familial accumulation of lung cancer.
Smoke & lung health
90 percent of lung cancer cases are attributable to smoking. The cigarette smoke contains numerous carcinogenic substances. The risk of developing bronchial carcinoma is for a smoker about 10-15 times as high as for a never-smoker. Of course, this risk increases with the number of cigarettes smoked daily and the duration of smoking. About every thirtieth smoker falls ill in the course of his life. For pipe and cigar smokers who do not inhale the smoke, the risk for lung cancer is significantly lower than for inhaled cigarette smoking, but still high compared to that of a non-smoker. However, there is a subgroup of cigars and pipe smokers who inhale like cigarette smokers. Here the risk is comparable to that of the cigarette smoker. Even passive smokers (people who do not smoke themselves, but stay in rooms where people smoke) have an increased risk of cancer: passive smoking increases lung cancer risk by a factor of 1.3.
Pollutants & lung health
The occupational lung cancer risk is significantly lower than the risk of smokers. About one percent of all cases of bronchogenic carcinoma is caused by the inhalation of substances that people have to deal with at their workplace. Asbestos is responsible for more than 90% of cases, but arsenic, beryllium, cadmium, chromium, nickel, aromatic hydrocarbons, and diesel exhaust also play a role. These substances are mainly used in metalworking, in coal gas and coke production, in foundries or in rubber production. Even with workers in uranium mines, the risk of lung cancer is due to contact with the naturally occurring radioactive noble gas radon elevated. Heavy air pollution – especially from diesel soot – can also increase lung cancer risk (1.5 times). Particularly in smokers pollutants – whether at work or in the outside air – lead to an additionally significantly increased lung cancer risk.
Nutrition & lung health
A low-vitamin diet increases the risk of developing lung cancer to about twice – especially among smokers. That’s why it’s important to eat fruits and vegetables regularly. For example, beta-carotene from leafy vegetables and carrots is said to have a protective effect against lung cancer. However, vitamins in the form of dietary supplements or high-dose supplements are not an alternative: In smokers, they do not seem to lower the risk of cancer, but even increase it. In relation to the damaging influence of smoking, however, the contribution of nutrition in the development of lung cancer is low overall.
lung Infections & injuries
Generally, scars in the lungs are associated with an increased risk of cancer due to previous inflammation or infection (such as tuberculosis or silicosis) or injuries. Because cancer develops preferentially in those areas of the lung, which are scarred as a result of tuberculosis or other illness. Here, too, smokers are additionally endangered.
A hereditary bias can also increase the risk of lung cancer. If one parent suffers from a bronchial carcinoma, the risk of children increases by two to three times.
Genetic Lung disease
Different types of lung cancer
Physicians distinguish two types of lung cancer the small-cell lung cancer (SCLC: small cell lung cancer ) that is growing very quickly and accounts for about 15 percent of cases, and non-small cell lung cancer ( NSCLC: non-small cell lung cancer ), which with about 85 percent occurs most frequently.
Non-small cell lung cancer is further distinguished between what is known as squamous cell carcinoma (40-50% of all lung cancers), adenocarcinoma (10-15%) and large cell carcinoma(5-10 percent). Non-small cell bronchial carcinomas grow more slowly and therefore have a better overall prognosis. What type of tumor is involved can only be determined by a microscopic examination of the cancerous tissue.
All carcinomas rarely cause discomfort at the beginning of their growth. Therefore, they are almost always discovered at random at an early stage, for example in x-ray examinations performed for a different reason. It is only in advanced stages that symptoms may appear that may indicate a carcinoma but other causes are also conceivable.
Possible complaints in a bronchial carcinoma
Early signs that may indicate lung cancer are especially persistent cough for four weeks, wheezing and chest pain. However, such symptoms are firstly not necessarily typical for a tumor disease, secondly, they also occur in many other diseases. In this respect, lung cancer is often not discovered early enough. On the other hand, there are good chances of recovery only if a bronchial carcinoma is treated as early as possible. In advanced disease stages, there is often rapid weight loss, bloody sputum, difficulty breathing and/or fever, usually triggered by concomitant infections.
The following symptoms may indicate a bronchial carcinoma and should, therefore, be clarified by the doctor:
- “Smoker’s bronchitis” (ie a persistent cough with sputum due to years of cigarette smoking)
- A stubborn cough that does not fade even after several weeks, and then suddenly changes
- Persistent hoarseness
- Bronchitis or a cold that does not improve despite treatment with antibiotics
- difficulty in breathing
- Constant pain in the chest
- Nocturnal sweating
- Expectoration with or without blood
- Swelling of the neck and face
- Loss of appetite or heavyweight loss
- General malaise and decay of strength
- Strong pain
Usually in later stages of the disease, especially in small cell bronchial carcinoma, cancer deposits in the brain (so-called brain metastases) can arise. Nerve damage causes headaches, nausea, impaired vision, and balance or even paralysis. Some tumors also release hormones into the blood and thus disrupt the natural hormone balance.
Grading & staging of a tumor
In a microscopic examination, not only the type of tumor but also the aggressiveness and growth rate of a tumor – and thus its prognosis – can be estimated. In the so-called “grading” the tumors are divided into four grades:
- G1 tumors: very similar to their original tissue, still well differentiated, growing slowly and not as aggressive.
- G2 tumors: moderately differentiated
- G3 tumors: poorly differentiated
- G4 tumors: undifferentiated, barely recognizable as a bronchial cell, grow rapidly and tend to grow aggressively into adjacent tissue.
However, information on the degree of differentiation due to “grading” only makes sense for squamous cell and adenocarcinomas. Large cell and small cell carcinomas always correspond to Grade 4 tumors.
The spread of lung cancer is assessed by “staging” according to the so-called TNM classification. The stage of cancer is characterized by the following three criteria:
- the size and extent of the tumor (T1-4),
- the number and location of the affected lymph nodes (English nodes, N0-3) and
- the absence or presence of metastases (M0 or M1).
For example, small tumors (such as T1 and T2) with no lymph node involvement (N0) and no daughter tumors (M0) have a more favorable prognosis. In small cell lung cancer, physicians also distinguish between a limited and a more extensive disease. While in limited disease the tumor is limited to one lung, it is said to be of advanced disease when cancer has spread to adjacent tissue in the chest and other parts of the body.
Complications & effects
Depending on the position of the tumor, it can narrow the air or esophagus or even close the large bronchi. Frequently, lung cancer patients also develop pneumonia and tumor bleeding. Those affected spit blood and suffer from venous congestion in the head and neck area. There may be fistulas, accumulation of blood in the pericardium and pleural effusions – also due to lymphatic drainage disorders. Disintegrating cancer can cause a high fever.
Lung cancer prevention
If lung cancer is suspected , the patient is first questioned by the doctor in detail about his symptoms and possible risk factors, and then thoroughly examined physically. This involves examining both blood and sputum in the laboratory and x-raying his lungs. A subsequent bronchoscopy allows the doctor to look into the lungs. In some cases, he has to confirm his diagnosis with additional methods such as ultrasound , computed tomography (CT) or fine needle biopsy (see below), which may require the patient to be admitted to a pulmonary clinic.
If lung carcinoma has been diagnosed, further examinations should follow, which should show, in particular, how far the tumor has already spread, whether lymph nodes are affected or even secondary tumors ( metastases ) have formed in other parts of the body. The stage of cancer is crucial for choosing the treatment strategy.
The blood values reflect the general condition of the patient and provide information about the functioning of individual organs such as kidneys and liver. In addition, the blood can be checked for the occurrence of so-called tumor markers – these are certain substances that are increasingly formed by tumor cells. However, as tumor markers can not be detected in all lung cancer patients and can also occur in healthy people, they do not play a major role in the diagnosis. They are more likely to be used in aftercare to control the disease process.
In a sputum examination , the patient’s coughed mucus is examined under the microscope for abnormal cells. Such cells may indicate tumors that are not yet visible on the radiograph. However, their absence does not automatically mean all-clear. Therefore, this test can not be used for the early detection of lung cancer .
During bronchoscopy , the doctor introduces a flexible tube ( endoscope ) into the bronchial tubes via the nose and trachea to patients who are anesthetized locally or under anesthesia . Using an optical device at the end of the endoscope, the doctor can examine the mucous membranes and use a small forceps, which is located next to the optical unit, to take a tissue sample (biopsy). Only the microscopic examination of this sample reveals whether a malignant tumor is present – and if so, which form of cancer it is. During the same examination, the doctor can also aspirate secretions from deeper bronchial sections and examine them, similar to the sputum, under the microscope for cancer cells .
If the cancerous area is unreachable due to its location for bronchoscopy, the doctor will perform a fine needle biopsy. He pushes from the outside a long, thin hollow needle through the patient’s chest into the suspicious area and sucks some tissue. The whole thing happens today usually under ultrasound – or computer tomographic control. The tissue is then examined microscopically for the presence of cancer cells.
Computed tomography (CT)
With the help of this special X-ray method, the doctor examines the patient’s body layer by layer. In the computer tomogram, he can detect the extent of the tumor and determine whether it has already affected adjacent organs. Thus, he receives important information about the extent to which vital organs are affected, whether the tumor can even be surgically removed and – if so – how extensive the operation is likely to be. In patients with bronchial carcinoma, computed tomography is also used to look for or eliminate the presence of cancer cells (metastases) in the head, but also in the chest and abdomen.
Magnetic Resonance Imaging (MRI)
Lying in a strong magnetic field, the patient is exposed to radio waves during this examination. The water molecules in the body “respond” to this signal at different speeds – depending on the type of tissue they are sitting in. From the resonance of their respective wave patterns, the computer calculates an image of the organs. In nuclear spin (as magnetic resonance tomography is also colloquially called) different structures stand out than with computed tomography. In addition, dislocations of cancer cells (metastases) in the brain, spinal cord and skeleton can be more clearly recognized. The waves and the magnetic field are innocuous for the patient.
Similar to magnetic resonance imaging ( MRI ), an ultrasound examination makes the internal organs visible without burdening the affected patient with harmful radiation. Using ultrasound, the doctor can determine whether the lung cancer has already spread to other organs such as the liver, kidneys, spleen and lymph nodes. An ultrasound examination of the heart can provide information about the performance of the heart muscle, which in turn is crucial for the choice of treatment method. Often affected people not only the lungs are damaged by regular tobacco consumption , but also their cardiac output (due to constricted coronary arteries).
With the help of bone scintigraphy, the doctor can detect whether the lung cancer has already spread secondary tumors into the bones (bone metastases). To do this, he injects small amounts of a radioactive substance into the bloodstream, which accumulates primarily in diseased bones. A camera recording radioactive radiation locates suspicious areas. A scintigraphic examination does not put a lot of strain on the patient as the radiation fades away very quickly.
Lung cancer often spreads through the lymphatics, and especially the lymph nodes of the mediastinum, which are close to the lungs, are particularly frequently attacked. In order to assess their condition, the physician must perform a mediastinoscopy : For this, he introduces the anesthetized patient via a small incision above the breastbone an optical probe in the space between the lungs. Using the endoscope, he can remove suspicious lymph nodes and then examine these tissue samples for the presence of cancer cells.
The choice of treatment depends on whether a small cell or non-small cell lung carcinoma is present and how far the disease has progressed. Since lung cancer patients almost always have a chronic inflammation of the bronchi with constriction, additional treatment of chronic bronchitis is very important in the treatment of bronchial carcinomas . Also respiratory distress, cough and pain can be alleviated.
Treatment of non-small cell lung cancer
In the treatment of non-small cell lung tumors, surgery and radiation are in the foreground: during surgery, the surgeon cuts out the tumor and a piece of adjacent healthy lung tissue. Frequently, the entire affected lung lobe (lobectomy) or a whole lung (pneumectomy) is removed, but in many cases can also be operated to maintain the organ. A surgical procedure is only possible if the general condition of the patient is good and the remaining lung sections can take over the respiratory function.
If this is not the case, or if the tumor already reaches neighboring, vital organs, radiotherapy must be performed. In this case, the cancer cells are irradiated from the outside with high-energy waves (taking advantage of the effect of ionizing radiation) and destroyed. Are being introduced X, Alpha, gamma or electron radiation. In the best case, the tumor is reduced by the radiation so far that it can still be surgically removed afterwards. Radiation therapy may also be performed following surgery (adjuvant radiotherapy) to destroy any remaining cancer cells. The prospect of success is limited, however, as often not all tumor cells can be destroyed or even the smallest tumor deposits have formed. In non-small cell lung cancer, chemotherapy is increasingly being used in combination with surgery and / or radiotherapy. The success of this treatment is currently being tested in clinical trials worldwide.
Treatment of small cell bronchial carcinoma
In small-cell bronchial carcinomas, which due to their rapid growth and early spread of secondary tumors (metastasis) can be operated on only rarely, chemotherapy is more effective than non-small cell carcinoma. The patient is given so-called cytostatics. These are drugs that inhibit cell division and act especially on the fast-growing cancer cells – less on healthy cells. Even if surgery is performed, chemotherapy is always performed before or after surgery to combat other possible (non-surgical) tumor cells. If distant metastases have already formed, the doctor tries to delay the course of the disease by means of chemotherapy. Thus, he can cure the patient only in a few cases, but possibly extend his life. As long as a small cell Lung cancer has a small extent, a combination of radiation and chemotherapy can be considered. Since small-cell lung tumors often form metastases in the brain, the patient’s skull is sometimes irradiated preventively. This radiation should help prevent the onset of cancer in the brain.
Active substances in the chemotherapy of bronchial carcinomas
Non-small cell lung carcinoma
Small cell bronchial carcinoma
erlotinib + gefitinib
Treatment of tumor pain
In the advanced stages of lung cancer, the so-called tumor pain (for example, as a result of an infestation of the pleuraor the chest wall), and their control in the foreground. They often affect the quality of life of the person affected more than other effects of the tumor. The doctor has a range of painkillers to morphine injections available to relieve the suffering. For painful bone metastases sometimes helps a targeted irradiation. If the entire skeleton is affected by the tumor, the doctor can administer to the person concerned radioactive substances that accumulate in the diseased bone and irradiate it from the inside (radionuclide treatment). Also, chemotherapy can relieve tumor-related pain in more than half of the patients and prevent worsening of the general condition. However, healing is no longer possible at this time.
lung cancer prevention
About 85 to 90 percent of all malignant lung tumors are due to smoking . Therefore, one can prevent lung cancer still best when on tobacco use completely eliminated and not be gathered up in smoke filledrooms . Even at an advanced age and after many years of smoking it is worthwhile stopping for many reasons. Those who are in contact with carcinogenic substances at the workplace should strictly adhere to the safety precautions. A healthy, vitamin-rich diet helps the body fight against cancer. The risk prevention is in lung cancer especially important because its chances of recovery are rather poor and there is currently no one hundred percent safe screening for early detection.
Aftercare & rehab
The purpose of follow-up examinations for lung cancer is to detect and treat a possible recurrence of the tumor (recurrence) in good time. Follow-up visits often follow a set schedule of visits to the doctor in the first year at 1, 3, 6, 9 and 12 months, the second year every 3 months, then every 6 months. However, significant differences are possible depending on the individual course. Unfortunately, the prognosis of the patient (ie, his chance of survival) does not improve decisively simply by the control examinations – but without the symptoms changing. In addition to a detailed conversation and a physical examination, the blood is often analyzed during follow-up examinations and an X-ray of the chest (thorax)made. After surgery, sometimes bronchoscopy (lung reflection) may be useful at longer intervals .
Inpatient rehabilitation stays should preferably be sought at particularly experienced tumor after-care clinics that are familiar with the specific needs of lung cancer patients. The aim is to improve the overall quality of life of those affected – that is, physically, socially, psychologically and professionally. Whether a rehabilitation measure in individual cases makes sense and is possible, decides the treating pulmonologist.