The lung cancer or lung cancer is a disease due to uncontrolled cell growth in lung tissue. This growth can give metastases, which are the invasion of adjacent tissue and infiltration beyond the lungs. The vast majority of primary lung cancers are carcinomas of the lung, derived epithelial cells.

According to WHO is the most common cause of cancer death in men and after breast cancer among women? It causes 1.3 million deaths per year in the world. The most common symptoms are shortness of breath, cough (possibly spitting of blood).

The main types of lung cancer are “small cell carcinoma” and “non-small cell carcinoma. This distinction is important because treatment depends on: lung carcinoma non small cell is often treated with surgery, while the overhead rail system with small cell carcinoma usually responds better to chemotherapy and radiotherapies.

The most common cause of lung cancer is chronic exposure to smoke tabac, including smoking passive.

Lung cancer can be seen on chest radiographs and CT. The diagnosis is confirmed by a biopsy. This is usually done by bronchoscope or CT-guided biopsy. Treatment and prognosis depend on the histological type of cancer, its stage (degree of spread), and the general state of health of the patient.

Classification

The vast majority of lung cancers are carcinomas – malignant states of proliferation of epithelial cells. There are two main types of lung carcinomas, classified according to size and appearance of the malignant cells under a microscope by a pathologist: non-small cell carcinomas (80.4%) or small cells (16.8%) 15. This classification, based on histological criteria, has important implications for clinical management and prognosis of the disease.

NON-SMALL CELL CARCINOMA

The non-small cells carcinomas are collected because their prognosis and treatment are similar. We distinguish three subtypes: lung cell carcinomas, Adenocarcinoma, among which there are subtypes papillary, solid, acinar and bronchioloalveolar lung carcinomas and large cell.

Representing 31.2% of lung cancers, lungs cell carcinoma of the lung usually starts near a major bronchus. Frequently found in the center of the tumor containing a hollow cavity of the necrotic tissue. Lung cell lung cancers often grow well differentiated more slowly than other types of cancers.

Adenocarcinoma is responsible for 29.4% of lung cancer. It usually originates in peripheral lung tissue. Most cases of anenocarcinome are linked to smoking, but among those who never smoked (“never smokers”), adenocarcinoma is the most common form of lung cancer.

CARCINOMA, SMALL CELL LUNG

Carcinoma, small cell lung (also called oat cell carcinoma ( “oat cell carcinoma”) is less common. It tends to occur in the larger airways (bronchi primary and secondary), and grows fast enough to become grand. The “oat cell” contains dense neurosecretory granules (vesicles containing neurohormones) that provide a combination of endocrine syndromes paraneoplasiques. Although more sensitive to chemotherapy at the beginning, however, it causes a worse prognosis, and is often at the stage of metastasis detection. Cancers of the lung are divided into small cell disease at a limited or extensive stage. This type of cancer is strongly associated with tabagisme.

Secondary cancers

The lung is a common place for the development of metastatic tumors in other parts of the body. These secondary cancers are identified by the organ of origin, so a metastasis of breast cancer in the lung is still known as breast cancer. They often have a characteristic round appearance at the radiography. In children, the majority of lung cancers are secondaires. The primary lung cancers are metastases preferentially to adrenal glands, liver, brain and OS.

Evolution

The stages of lung cancer are characterized by the degree of extension of cancer from its original site. This is an important factor in prognosis and potential treatment of lung cancer. Carcinoma of the lung non-small cell evolves from stage IA (“an A” best prognosis) IB or II to IV (“four” or widespread metastatic cancer, the worst prognosis). Lung carcinoma small cell is classified as limited stage if confined to one half of the chest and in the field of radiotherapy alone, otherwise it is classified as stage extensive.

CAUSES OR RISK FACTORS

The main causes of lung cancer (and cancer in general) include carcinogens (such as those found in tobacco smoke), ionizing radiation, and viral infections. Exposure to these causes changes, which accumulate in the DNA of the tissue covering the inside of the bronchi (bronchial epithelium). More tissue is altered, the greater the risk of developing cancer augmenting.

Lung cancer is recognized as an occupational disease in France in case of exposure to ionizing radiation, asbestos, chromium, nickel, the tars, the arsenates and certain other chemicals.

Etiology

Like many other cancers, lung cancer is caused by the activation of ontogenesis or inactivation of suppressor genes tumors. Ontogenesis is genes that are believed to make their bearers more likely to develop cancer. The proto-ontogenesis is believed to turn into oncogenes under the action of certain cancer genes. Mutations in the proto-oncogene K-ras are responsible for 10 to 30% of Adenocarcinoma of lung.

The EGFR (epidermal growth factor), or under its English acronym EGFR controls the proliferation, apoptosis, angiogenesis and invasion by the tumor. Mutations and amplification of EGFR are common in lung cancer non-small cell, and provide a basis for treatment with EGFR inhibitors.  Chromosomal damage can lead to loss of heterozygosis. This can cause the inactivation of genes anti-ontogenesis. Damage to chromosomes 3p, 5q, 13q and 17p are particularly common in lung carcinoma small cell. The p53 tumor suppressor gene, located on chromosome 17p is

Prevention

Prevention is the best and least expensive ways to fight lung cancer. While in most countries, industrial and domestic carcinogens have been identified and banned, smoking is still widespread. The elimination of smoking is a major goal in preventing lung cancer, which remains home to 90%, and smoking cessation is a major preventive instrument in this processes.

The most important are the prevention programs against youth. In 1998, an Agreement under Regulation (in: Master Settlement Agreement) allowed 46 U.S. states to require an annual payment from the industry tabac. Of the amounts of these regulations and taxes on tobacco, public health departments of every state funded prevention programs, but arrive at the amount recommended by the Centers for Disease Control, which amount to 15% of these are.

The policy intervention to reduce passive smoking in public places such as restaurants and workplaces has become widespread in many Western countries. California is leading the way in banning smoking in public places in 1998. Ireland has played a similar role in Europe in 2004, followed by Italy and Norway in 2005, Scotland and several others in 2006,

England in 2007 and France in 2008, New Zealand has banned smoking in public places from 2004. The state of Bhutan has completely banned smoking. In many countries, pressure groups are campaigning for similar bans. In 2007, Chandigarh became the first city in India to become tobacco-free. India has introduced a total ban on smoking in public places October 2, 2008.

The arguments cited against the ban are the criminalization of smoking, increasing risks of smuggling, and simply the difficulty of controlling this interdiction. A study in 2008 on 75 000 persons of middle and advanced ages has shown that long term use of multivitamin supplements – vitamins C, E and foliate – does not reduce the risk of lung cancer. Instead, the study indicates that taking long-term high-dose vitamin E supplements may even increase this risque.

The World Health Organization (WHO) has called on governments to introduce a total ban on tobacco advertising to prevent young people from starting to smoke. She felt that this type of ban has reduced consumption by 16% where it has been institute.

Diagnosis

Signs and symptoms

Obstruction of a bronchus by a major lung cancer: bronchoscopic view
the clinical signs suggestive of lung cancer are multiple but often little expressions.

• DIFFICULTY BREATHING.
• ABNORMAL SHORTNESS.
• WHEEZING.
• DYSPHONIA (HOARSE VOICE).
• CHRONIC COUGH.
• HEMOPTYSIS (SPITTING BLOOD).
• RECURRENT RESPIRATORY INFECTIONS.
• CHEST PAIN.
• WEIGHT LOSS.
• FATIGUE.
• DYSPHAGIA.

Impaired general condition, asthenia (weakness, fatigue), loss of appetite
Clubbing – bulging at the tip of the fingers, especially the fingernails (uncommon)

Differential Diagnosis

Depending on the type of tumor, paraneoplastic syndrome may draw attention to the disease at its debut. In lung cancer, these phenomena may include myasthenia syndrome Lambert-Eaton (muscle weakness due to auto-antibodies), hypocalcaemia, or Schwartz-Bartter syndrome (abnormal secretion of antidiuretic hormone by the tumor). Tumors of the top of lung can (Pancoast syndrome) invade the adjacent portion of the sympathetic nervous system, leading to changes in perspiration, and problems of the eye muscles (designated by a combination of Claude syndrome Bernard-Horner) and a weak hand muscles due to the invasion of the brachial plexus.

Many of the symptoms of lung cancer (bone pain, fever and weight loss) are non-specific in older patients; they can be attributed to a comorbidite. In many patients, the cancer has already spread beyond the original site when the patient feels the first symptoms and consults. Frequent sites of metastasis are the brain, bone, adrenal glands, contralateral lung (the other side), liver, pericardium and reins. About 10% of all patients with lung cancer have no symptoms diagnosis of these cancers is discovered by chance after a radiograph of the poitrine.

Chest X-ray showing a cancerous tumor in the left lung in the form of an oval opacity.

The chest radiograph is the first step to take if a patient complains of symptoms that suggest lung cancer. This may reveal an obvious mass, widening of the mediastinum (which suggests an extension to the lymph nodes there), atelectasis (collapse),

In the absence of radiographic signs, but if the suspicion is high (e.g., a heavy smoker with hemoptysis), a bronchoscopy or scanner can provide the necessary information. Bronchoscopy or CT-guided biopsy is often used to identify the type of tumeur.

Treatment

The treatment of lung cancer depends on the exact type of cancer cell, the extension of cancer, and the general state of health of the patient. The most common treatments include surgery, chemotherapy and various types of radiotherapy.

Surgery

If the tests confirm lung cancer, CT scans, often positron emission tomography (PET) are used to determine if the cancer is localized and can be addressed by surgery, or if the point spread no longer be removed by surgery. Blood tests and spirometry (lung function testing) are also needed to determine if the patient is well enough to withstand the operation. If spirometry reveals a low respiratory reserve (often due to obstructive syndrome), surgery may be indicated-cons.

The surgery itself has a death rate of about 4.4%, depending on the condition of the patient’s lungs and other factors risque. Surgery is usually an option only on non-small cell carcinoma, limited to one lung to stage IIIA. This is determined by medical imaging (CT or PET). An adequate preoperative respiratory reserve must be present to allow the lung to function properly after tissue resection.

The procedures include peripheral wedge resection (resection of part of a lobe), segmentectomy (resection of an anatomical division of a lobe), lobotomy (one lobe), bilobectomy (two lobes), and orpneumonectomy (whole lung). In patients with a sufficient respiratory reserve, lobotomy is the preferred choice because it is the method that minimizes the risk of local recurrence. If the respiratory reserve is insufficient, we may prefer cuneiform resection. Brach therapy (use of surgery to insert radioactive material, leading to a radiological procedure at the same time as surgery) to radioactive iodine on the lips of the wedge resection may lower recurrence rate than the lobotomy.

Thoracoscopic surgery by video-endoscopy (CTVE) and even lobectomy by CTVE have methods for minimally invasive surgery for lung cancer, which can have the benefits of faster recovery, decreased hospital stay and costs.

Chemotherapy

Lung carcinoma small cell is treated mainly by chemotherapy and radiotherapy because the surgery showed no advantage for survival. Primary chemotherapy is also used for non-small cell carcinomas have metastasized.

Treatment depends on the type of tumor. The non-small cell carcinoma is often treated with cisplatin or carboplatin in combination with gemcitabine, paclitaxel, docetaxel, etoposide, or vinorelbine. For small cell carcinoma, cisplatin and etoposide are the most frequently utilises. But it also uses combinations of carboplatin, gemcitabine, paclitaxel, vinorelbine, topotecan and irinotecan.