Lung Cancer: The Bad and the Worse

In terms of deaths caused by various forms of cancer, lung cancer ranks second only to breast cancer. The National Cancer Institute recently reported that an estimated 172,570 new cases of lung cancer will be reported this year and that 163,510 American will die from this disease.

Lung cancer is caused predominantly by smoking. One expert says that in the case of Small Cell Lung Carcinoma (cancer), it is almost always caused by smoking.

Lung cancer is called lung cancer because it begins in the lungs. The right lung has three sections, the left lung has two. Each section is called a lobe. Sometimes the term “bronchogenic cancer” is used to refer to lung cancer as most lung cancers begin in one of the two breathing tubes, the bronchi, in the lungs.

There are two major types of lung cancer. One is the Small Cell Lung Cancer (SCLC) mentioned in the previous paragraph. The other is Non-Small Cell Lung Cancer (NSCLC).

Non-Small Cell Lung Cancer has three subtypes: Adenocarcinoma, Squamous Cell Carcinoma and Large Cell Undifferentiated Carcinoma. NSCLC is the least “serious” of the two types. In fact, if it is detected early, it is possible that it can be cured with surgery.

Andenocarcinoma accounts for about 40 percent of lung cancer cases in the U.S. It is the most common cancer among women and can be seen in non-smokers. Squamous Cell Carcinoma represents about 30 to 35 percent of lung cancers and tends to stay localized in the chest longer than other types of lung cancer. Large Cell Undifferentiated Carcinoma represents only about five to 15 percent of lung cancers in the U.S. The incidence of this type of cancer seems to be decreasing.

The worst and most aggressive form of lung cancer is Small Cell Lung Cancer. It represents only about 15 to 20 percent of all lung cancers. It spreads to the lymph nodes and other organs more quickly than NSCLC, but seems more responsive to chemotherapy drugs.

Non-Small Cell Lung Cancer is described in stages – Stage I through IV. WebMD recently reports survival rates of NSCLC as:

· Stage 1A or 1B with no lymph node involvement has a five-year survival rate of 43 to 64 percent when treated with surgery.

· Stage IIA or IIB with a single lymph node involvement, when treated with surgery, has a five-year survival rate of 20 to 40 percent.

· Stage IIIA with a single lymph node involvement in the center of the chest, when treated with surgery has a five-year survival rate of 15 to 25 percent.

· Stage IIIB with lymph node involvement in the chest and neck, when treated with radiation without other treatment, has a five-year survival rate of five to seven percent.

· Stage IIIB with lymph node involvement in the chest and neck, when treated with radiation and chemotherapy, has a five-year survival rate between seven and 17 percent.

· Stage IV with extensive lymph node involvement or cancer that has spread to other organs, hen treated with chemotherapy and palliative care to reduce symptoms and increase comfort has a one-year survival rate.

The prognosis is much bleaker for patients with Small Cell Lung Cancer. This form of cancer is found in two stages: limited or extensive. The limited version is that which is found in only one lung and nearby lymph nodes. The extensive type has spread outside the lung to other parts of the chest or body (metastasized). Limited SCLC when treated with chemotherapy and radiation therapy has an average survival time of 18 to 20 months. The extensive form of SCLC when treated with chemotherapy has a survival time of 10 to 12 months. Ttwo-year survival rate is one to three percent, and the five-year survival rate less than two percent.

The majority of people diagnosed with SCLC will die despite the best available treatment.

While surgery plays the most important part in the treatment of Non-Small Cell Lung Cancer, chemotherapy is always the chosen treatment for Small Cell Lung Cancer. In the case of limited stage SCLC, radiation therapy may also be used as the cancer is still localized to the chest area where radiation can be focused.

Small Cell Cancer Cells are so small they cannot be seen on scans. Even in the case of limited stage SCLC, it is possible for some cells to break away from the primary cancer and migrate to anywhere in the body. For this reason, chemotherapy is the preferred treatment as it treats the whole body, unlike radiation therapy which must be focused on a selected area. In act, chemotherapy is the preferred treatment for both limited and extensive stage Small Cell Lung Cancer.

Smoking And Lung Cancer - The True Facts

The bad news is that smoking increases your risk of developing lung cancer. And I can tell you that 90% of lung cancer deaths in men and 80% of lung cancer deaths in women are linked with smoking. And lung cancer is not the only cancer related to smoking. Strong links have been shown between smoking and cancer of the mouth, the larynx, the esophagus, the bladder, the stomach and the kidneys. But cancer was the first disease that was linked to smoking, and it is the leading cause of cancer related deaths in the United States.

Here are some statistics to consider:

Men who are smokers are 23 times more likely to get cancer than men who do not smoke.

Women who are smokers are 13 times more likely to develop lung cancer than women who do not smoke.

You do not decrease the risk of catching lung cancer by smoking low tar, low nicotine or 'light' cigarettes.

Did you know that there are over 4000 chemicals in cigarette smoke? At least 60 of these are known carcinogens.

Carcinogens damage the DNA in cells that controls their growth. One of the characteristics of malignant cancer cells is unrestrained growth and replication of cells.

30% of cancer deaths annually is directly attributed to cigarette smoking.

87% of lung cancer deaths is caused by cigarette smoking.

Secondhand smoke accounts for about 5% of all newly diagnosed cases of lung cancer.

Secondhand smoke, or passive smoking causes about 3000 lung cancer deaths in each and every year.

If you quit smoking before the age of 35 you can reduce your risk of developing lung cancer by as much as 90%.

Even quitting smoking before you reach 50 will substantially reduce your risk of developing cancer.

It is known that 7 of 8 people who contracted lung cancer will not be alive five years after their diagnosis.

The more you smoke, the more you increase your risk of actually developing lung cancer.

Lung cancer is decreasing in the United States as the number of smokers have decreased.

People try to tell you, that it is not proven that cigarette smoking actually causes lung cancer. This is true to some extent. For example, you may have a genetic predisposition to getting cancer. Not everything is known why some people develop cancer and others do not. Some people can smoke for years and do not get it, and some people get it who never smoked at all. But there is one thing you can be sure of, smoking will increase your risk of developing lung cancer. And if you do stop smoking, you will decrease your risk of developing lung cancer over time.

Lung Cancer: Basic Facts

We all have heard of lung cancer but how many of us are well aware of its symptoms? The lung cancer is one of the most perilous diseases that kill thousands of Americans every year and each year the number of cases are increasing. With the occurrences of lung cancer on the rise, it is essential that we learn about the basic factors leading to lung cancer and what should be the courses of action in case of lung cancer diagnosis. Here are the basic information regarding lung cancer that will help you to understand how and when it develops and how to steer clear of this killer disease.

Lung cancer is that condition of your lungs where an abnormal reproduction of cells takes place. And it can happen in one or both of your lungs. Sometimes lumps of cancerous cells or the tumors invade the organs. Our lungs allow the oxygen from the air to pass into the bloodstream and carbon dioxide to eliminate from the system. Now any kind of lung disease including lung cancer impairs this function of lungs to transfer oxygen into blood and remove carbon dioxide from it. The result is many kinds of disorders relating to breathing trouble and cough.

Do you know what the most dreadful part of the lung cancer is? One rarely comes to suspect that he or she is suffering from lung cancer until it is too late and goes beyond any kind of treatment. This is because, signs and symptoms associated with lung cancer are never acute or alarming until the later stages of malignancy and it is often at this stage when someone starts to experience the typical symptoms of lung cancer. So it is recommended that if you ever experience any symptom even remotely related to lung cancer, rush to the doctor without delay so that in case of diagnosis of lung cancer you can avail the treatments as early as possible. The earlier the disease is diagnosed; greater are the chances of survival.

So what are the common symptoms of lung cancer? Nagging cough that seems never to end coupled with constant chest pain may be the warning of something being grossly wrong with your lungs. If you are suffering from recurring pneumonia or bronchitis, it may be an indication that you should immediately see an oncologist. The person displaying certain apathy for food followed by a remarkable weight loss may be an indication of lung cancer and the patients of lung cancer often complain of fatigue. However, swelling of neck and face is also one of the symptoms of lung cancer.

Remember lung cancer can be prevented if you give up smoking. So stay away from the cigars, cigarettes, pipes and other tobacco products. Also insist that the smokers should always smoke inside the smoking zone; do not allow the second hand smokes damage your lungs

Screening and secondary prevention

Because prognosis depends heavily on early detection there have been several attempts at secondary prevention. Regular chest radiography and sputum examination programs were not effective in early detection of this cancer and did not result in a reduction of mortality.

Computed tomography (CT) scanning is now being actively evaluated as a screening tool for lung cancer, and it is showing promising results. The National Cancer Institute (USA) is currently completing a randomized trial comparing CT scans with chest radiographs. Several single-institution trials are ongoing around the world. A large group of investigators (the International Early Lung Cancer Action Project) are currently collating the results of 26,000 screen-detected lung cancers and are showing excellent preliminary survivals with these patients. More work is needed in this area

Primary prevention

Prevention is the most cost-effective means of fighting lung cancer on the national and global scales. While in most countries industrial and domestic carcinogens have been identified and banned, tobacco smoking is still widespread. Eliminating tobacco smoking is a primary goal in the fight to prevent lung cancer, and smoking cessation is the most important preventative tool in this process.

Policy interventions to decrease passive smoking (e.g. in restaurants and workplaces) have become more common in various Western countries, with California taking a lead in banning smoking in public establishments in 1998, Ireland playing a similar role in Europe in 2004, followed by Norway in 2005 and Scotland as well as several others in 2006. New Zealand has also recently banned smoking in public places. (See Smoking ban).

Only the Asian state of Bhutan has a complete smoking ban (since 2005). In many countries pressure groups are campaigning for similar bans. Arguments cited against such bans is criminalisation of smoking, increased risk of smuggling and the risk that such a ban cannot be enforced.

Epidemiology

The population segment most likely to develop lung cancer is the over-fifties who also have a history of smoking. Lung cancer is the second most commonly occurring form of cancer in most western countries, and it is the leading cancer-related cause of death for men and women. In the US, 175,000 new cases are expected in 2006 [19]: 90,700 in men and 80,000 in women. Although the rate of men dying from lung cancer is declining in western countries, it is actually increasing for women due to the increased takeup of smoking by this group. Among lifetime non-smokers, men who have never smoked have higher age-standardized lung cancer death rates than women. Of the 80,000 women who are diagnosed with lung cancer in 2006, approximately 70,000 are expected to die from it.[20]

The British Doctors Study, published in the 1950s, first offered solid evidence on the link between lung cancer and smoking.

Not all cases of lung cancer are due to smoking, but the role of passive smoking is increasingly being recognised as a risk factor for lung cancer, leading to policy interventions to decrease undesired exposure of non-smokers to others' tobacco smoke.

In the Second World and Third World, smoking-related lung cancer is rising rapidly in incidence. Countries such as China are expected to see a marked increase in lung cancer cases as smoking is exceedingly common and other causes of death (such as infections) are becoming less common, revealing an "iceberg" of pulmonary neoplasms. Cheap tobacco products and heavy advertising are seen by health campaigners as a major problem in these countries.

Interventional radiology

Radiofrequency ablation is increasing in popularity for this condition as it is nontoxic and causes very little pain. It seems especially effective when combined with chemotherapy as it catches the cells inside a tumor—the ones difficult to get with chemotherapy due to reduced blood supply to the inside of the tumor. It is done by inserting a small heat probe into the tumor to cook the tumor cells. The body then disposes of the cooked cells through its normal eliminative processes.

Radiotherapy

Radiotherapy is often given together with chemotherapy, and may be used with curative intent in patients who are not eligible for surgery. A radiation dose of 40 or more Gy in many fractions is commonly used with curative intent in non-small cell lung cancer; typically in North America, the dose prescribed is 60 or 66 Gy in 30 to 33 fractions given once daily, 5 days a week, for 6 to 6½ weeks. For small cell lung cancer cases that are potentially curable, in addition to chemotherapy, chest radiation is often recommended. For these small cell lung cancer cases, chest radiation doses of 40 Gy or more in many fractions are commonly given; typically in North America, the dose prescribed is 45 to 50 Gy and can be given in either once daily treatments for 5 weeks or twice daily treatments for 3 weeks.

For both non-small cell lung cancer and small cell lung cancer patients, radiation of disease in the chest to smaller doses (typically 20 Gy in 5 fractions) may be used for symptom control.

Targeted therapy

In recent years, various molecular targeted therapies have been developed for the treatment of advanced lung cancer. Gefitinib (Iressa) is one such drug, which targets the epidermal growth factor receptor (EGF-R) which is expressed in many cases of NSCLC. However despite an exciting start it was not shown to increase survival, although females, Asians, non-smokers and those with the adenocarcinoma cell type appear to be deriving most benefit from gefitinib.

A newer drug called erlotinib (Tarceva) has been shown to increase survival in lung cancer patients and has recently been approved by the FDA for second-line treatment of advanced non-small cell lung cancer.[2]. Similar to gefitinib, it appeared to work best in females, Asians, non-smokers and those with the adenocarcinoma cell type.

Treatment of non-small cell lung cancer is evolving and the next few years could present exciting developments and new targeted therapies for lung cancer.

Chemotherapy

Small-cell lung cancer is treated primarily with chemotherapy, as surgery has no demonstrable influence on survival. Primary chemotherapy is also given in metastatic NSCLC.

The combination regimen depends on the tumour type:

* NSCLC: cisplatin or carboplatin, in combination with gemcitabine, paclitaxel, docetaxel, etoposide or vinorelbine. In metastatic lung cancer, the addition of bevacizumab when added to carboplatin and paclitaxel was found to improve survival (though in this study, patients with squamous cell lung cancer were excluded because of problems with pulmonary hemorrhage in this group in the past).
* SCLC: cisplatin or carboplatin, in combination etoposide or ifosfamide; combinations with gemcitabine, paclitaxel, vinorelbine, topotecan and irinotecan are being studied

Surgery

Surgery is only an option in NSCLC and if the disease is limited to one lung and has not spread beyond its confines. This is assessed with medical imaging (computed tomography, positron emission tomography). Furthermore, as stated, a sufficient respiratory reserve needs to be present to allow for the removal of large amounts of lung tissue. Procedures performed include lobectomy (removal of one lobe), bilobectomy (two lobes) or pneumonectomy (removal of a whole lung).

The role of sub lobar resection (extended wedge resection) continues to be debated for the primary management of NSCLC. Although overall survival appears to be equivalent to that of lobectomy resection, the local recurrence rate has been documented to be over three times more common (19% compared to 5%). Accordingly, sub lobar resection has historically been used as a "compromise resection" approach for the management of small (less than 3 centimeters diameter) stage I peripheral NSCLC identified in patients with impaired cardiopulmonary reserve. Recent reports of the use of intraoperative radioactive iodine brachytherapy implants at the margins of sublobar resection suggest that local recurrence can be reduced to that of lobectomy when this is used as a surgical adjunct to sublobar resection.

The role of anatomic segmentectomy (a larger sublobar resection) with complete lymph node staging has also been found to have potential survival benefits similar to lobectomy. Such resections should be limited to peripheral small (less than 2 centimeter diameter) stage I NSCLC where a margin of resection equivalent to the diameter of the tumor can be achieved.

Five-year prognosis is often as good as 70% following complete resection of limited (lesions limited to the lung tissue without lymph node spread - stage 1) disease.

After surgery, adjuvant chemotherapy may be recommended if lymph nodes within the lung tissues resected (stage 2) or the mediastinum (lymph nodes in the peri-tracheal region -stage 3) are found to be positive for cancer spread. Survival may be improved by up to 15% above patients receiving only surgical resection in these circumstances. The role of adjuvant chemotherapy for patients with large stage 1 NSCLC (tumors greater than 3 centimeters diameters without lymph node involvement - stage 1b) remains controversial.

The NCI Canada study JBR.10 treated patients with stage 1B to 2B NSCLC with vinorelbine and cisplatin chemotherapy and showed a significant survival benefit of 15% over 5 years. However subgroup analysis of patients in stage IB showed that chemotherapy did not result in any survival gain in them. Similarly, while the Italian ANITA study showed a survival benefit of 8% over 5 years with vinorelbine and cisplatin chemotherapy in stages 1B to 3A patients, subgroup analysis also showed no benefit in the 1B stage.

The Cancer and Leukemia -Group B (CALGB) study was a randomized study which examined the use of carboplatin and paclitaxel chemotherapy in patients with stage 1B disease. Unfortunately, although initial immature result in 2004 was encouraging, an update at the recent American Society of Clinical Oncology meeting (June 2006) reported that the findings are now negative with no survival advantage with the use of adjuvant chemotherapy in patients with this stage of disease. However, exploratory analysis of patients in the CALGB study suggested that perhaps those with tumors equal or greater than 4cm in size may still benefit.

At present, it is standard practice to offer patients with resected stage 2-3A NSCLC adjuvant 3rd generation platinum based chemotherapy (e.g. cisplatin and vinorelbine). Adjuvant chemotherapy for patients with stage 1B remains controversial as clinical trials have not clearly demonstrated a survival benefit.

Treatment

Treatment for lung cancer depends on the cancer's specific cell type, how far it has spread, and the patient's performance status. Common treatments include surgery, chemotherapy, and radiation therapy.

Lung cancer staging

Lung cancer staging is an important part of the assessment of prognosis and potential treatment for lung cancer.

See non-small cell lung cancer staging

Genetics and viruses

Oncogenes are genes that are believed make people more susceptible to cancer. Proto-oncogenes are believed to turn into oncogenes when exposed to particular carcinogens. Viruses are also suspected of causing cancer in humans, as this link has already been proven in animals. Genetic susceptibility and viral infection are not of major importance in lung cancer, but they may influence pathogenesis.

Radon gas

Radon is a colorless and odourless gas generated by the breakdown of radioactive radium, which in turn is the decay product of uranium, found in the earth's crust. Radon exposure is the second major cause of lung cancer after smoking. The radiation ionizes genetic material, causing mutations that sometimes turn cancerous. Radon gas levels vary by locality and the composition of the underlying soil and rocks. For example, in areas such as Cornwall in the UK (which has granite as substrata), radon gas is a major problem, and buildings have to be force-ventilated with fans to lower radon gas concentrations. In the US, the EPA estimates that one in 15 homes has radon levels above the recommended standard.

Radon causes lung cancer because it causes arbitrary damage to the chromosomes and DNA molecules contained in the nucleus of the cell.

Percentage of lung cancer deaths

Percentage of lung cancer deaths attributable to smoking in the developed world 35-69 years 70 years+ All ages
Men 93.9 90.3 92.5
Women 68.8 68.9 68.8
Both 88.7 84.3 86.6

The extensive attempts made by Philip Morris to delay the release of the 1997 IARC study, to affect the wording of its conclusions, to neutralise its negative results for their business, and to counteract its impact on public and policymakers' opinion has been documented by Ong & Glantz in The Lancet[16]. Their work was based on 32 million pages of documents made public as part of the settlement of the 1998 legal case of State of Minnesota and Blue Cross/Blue Shield of Minnesota vs Philip Morris Inc, et al. and available at Philip Morris' own website[17].

Recent investigation of sidestream smoke suggests it is more dangerous than direct smoke inhalation[18].

Asbestos

Asbestos can cause a variety of lung diseases. It increases the risk of developing lung cancer. There is a synergistic effect between tobacco smoking and asbestos in the formation of lung cancer.

Asbestos can also cause cancer of the pleura, called mesothelioma (which is distinct from lung cancer)

The role of smoking

Smoking, particularly of cigarettes, is by far the main contributor to lung cancer, which at least in theory makes it one of the easiest diseases to prevent. In the United States, smoking is estimated to account for 87% of lung cancer cases (90% in men and 79% in women), and in the UK for 90%. Cigarette smoke contains 19 known carcinogens[2] including radioisotopes from the radon decay sequence, nitrosamine, and benzopyrene. Additionally, nicotine appears to depress the immune response to malignant growths in exposed tissue. The length of time a person continues to smoke as well as the amount smoked increases the person's chances of contracting lung cancer. If a person stops smoking, these chances steadily decrease as damage to the lungs is repaired and contaminant particles are gradually vacated. More recent work has shown that, across the developed world, almost 90% of lung cancer deaths are caused by smoking[3].

Passive smoking—the inhalation of smoke from another's smoking— is claimed to be a cause of lung cancer in non-smokers. Studies from the USA (1986[4], [5], 1992[6], 1997[7], 2001[8], 2003 [9]), Europe (1998[10]), the UK (1998[11], [12]), and Australia (1997[13]) have consistently shown a significant increase in relative risk among those exposed to passive smoke.

The (EPA) in 1993 claimed that about 3,000 lung cancer-related deaths a year were caused by passive smoking. However, since this report was based on a study that was alleged to be heavily biased and was ruled by a federal judge to be "unscientific", the EPA report was declared null and void by a federal judge in 1998([14],[15]).

Smoking, particularly of cigarettes, is by far the main contributor to lung cancer, which at least in theory makes it one of the easiest diseases to prevent. In the United States, smoking is estimated to account for 87% of lung cancer cases (90% in men and 79% in women), and in the UK for 90%. Cigarette smoke contains 19 known carcinogens[2] including radioisotopes from the radon decay sequence, nitrosamine, and benzopyrene. Additionally, nicotine appears to depress the immune response to malignant growths in exposed tissue. The length of time a person continues to smoke as well as the amount smoked increases the person's chances of contracting lung cancer. If a person stops smoking, these chances steadily decrease as damage to the lungs is repaired and contaminant particles are gradually vacated. More recent work has shown that, across the developed world, almost 90% of lung cancer deaths are caused by smoking[3].

Passive smoking—the inhalation of smoke from another's smoking— is claimed to be a cause of lung cancer in non-smokers. Studies from the USA (1986[4], [5], 1992[6], 1997[7], 2001[8], 2003 [9]), Europe (1998[10]), the UK (1998[11], [12]), and Australia (1997[13]) have consistently shown a significant increase in relative risk among those exposed to passive smoke.

The (EPA) in 1993 claimed that about 3,000 lung cancer-related deaths a year were caused by passive smoking. However, since this report was based on a study that was alleged to be heavily biased and was ruled by a federal judge to be "unscientific", the EPA report was declared null and void by a federal judge in 1998([14],[15]).

four major causes of lung cancer

There are four major causes of lung cancer (and cancer in general):

* Carcinogens such as those in cigarette smoke
* Radiation exposure
* Genetic susceptibility
* Viral infection

Causes lung cancer

Causes

Exposure to carcinogens, such as those present in tobacco smoke, immediately causes cumulative changes to the tissue lining the bronchi of the lungs (the bronchial mucous membrane) and more tissue gets damaged until a tumour develops.

Metastatic

The lung is a common place for metastasis from tumors in other parts of the body. These cancers, however, are identified by the site of origin, i.e., a breast cancer metastasis to the lung is still known as breast cancer. The adrenal glands, liver, brain, and bone are the most common sites of metastasis from primary lung cancer itself.

Small cell lung cancer

M8041/3) Small cell carcinoma (SCLC, also called "oat cell carcinoma") is the less common form of lung cancer. It tends to start in the larger breathing tubes and grows rapidly becoming quite large. The oncogene most commonly involved is L-myc. The "oat" cell contains dense neurosecretory granules which give this an endocrine/paraneoplastic syndrome association. It is more sensitive to chemotherapy, but carries a worse prognosis and is often metastatic at presentation. This type of lung cancer is strongly associated with smoking.

The non-small cell lung cancers

The non-small cell lung cancers (NSCLC) are grouped together because their prognosis and management is roughly identical. When it cannot be subtyped, it is frequently coded to 8046/3. The subtypes are:

* (M8070/3) Squamous cell carcinoma, accounting for 20% to 25% of NSCLC, also starts in the larger breathing tubes but grows slower meaning that the size of these tumours varies on diagnosis.
* (M8140/3) Adenocarcinoma is the most common subtype of NSCLC, accounting for 50% to 60% of NSCLC. It is a form which starts near the gas-exchanging surface of the lung. Most cases of the adenocarcinoma are associated with smoking. However, among non-smokers and in particular female non-smokers, adenocarcinoma is the most common form of lung cancer. A subtype of adenocarcinoma, the bronchioalveolar carcinoma, is more common in female non-smokers and may have different responses to treatment.
* Large cell carcinoma is a fast-growing form that grows near the surface of the lung. It is primarily a diagnosis of exclusion, and when more investigation is done, it is usually reclassified to squamous cell carcinoma or adenocarcinoma.

Type of lung cancer

There are two main types of lung cancer categorized by the size and appearance of the malignant cells seen by a histopathologist under a microscope: non-small cell (80%) and small-cell (roughly 20%) lung cancer. This classification although based on simple pathomorphological criteria has very important implications for clinical management and prognosis of the disease.

Diagnosis lung cancer

Diagnosis

Performing a chest X-ray is the first step if a patient reports symptoms that may be suggestive of lung cancer. This may reveal an obvious mass, widening of the mediastinum (suggestive of spread to lymph nodes there), atelectasis (collapse), consolidation (infection) and pleural effusion. If there are no X-ray findings but the suspicion is high (e.g. a heavy smoker with blood-stained sputum), bronchoscopy and/or a CT scan may provide the necessary information. In any case, bronchoscopy or CT-guided biopsy is often necessary to identify the tumor type.

If investigations have confirmed lung cancer, scan results and often positron emission tomography (PET) are used to determine whether the disease is localised and amenable to surgery or whether it has spread to the point it cannot be cured surgically. PET is not useful as screening, as not all malignancies are positive on PET scan (such as bronchoalveolar carcinoma), and lung infections may be positive on PET Scan.

Blood tests and spirometry (lung function testing) are also necessary to assess whether the patient is well enough to be operated on. If spirometry reveals a very poor respiratory reserve, as may occur in chronic smokers, surgery may be contraindicated.

Signs and symptoms lung cancer

Signs and symptoms

Symptoms that suggest lung cancer include:

* dyspnea (shortness of breath)
* hemoptysis (coughing up blood)
* chronic cough or change in regular coughing pattern
* wheezing
* chest pain or pain in the abdomen
* cachexia (weight loss), fatigue and loss of appetite
* dysphonia (hoarse voice)
* clubbing of the fingernails (uncommon)
* difficulty swallowing

If the cancer grows into the lumen it may obstruct the airway, causing breathing difficulties. This can lead to accumulation of secretions behind the blockage, predisposing the patient to pneumonia.

Many lung cancers have a rich blood supply. The surface of the cancer may be fragile, leading to bleeding from the cancer into the airway. This blood may subsequently be coughed up.

Depending on the type of tumor, so-called paraneoplastic phenomena may initially attract attention to the disease. In lung cancer, this may be Lambert-Eaton myasthenic syndrome (muscle weakness due to auto-antibodies), hypercalcemia and SIADH. Tumors in the top (apex) of the lung, known as Pancoast tumors, may invade the local part of the sympathetic nervous system, leading to changed sweating patterns and eye muscle problems (a combination known as Horner's syndrome), as well as muscle weakness in the hands due to invasion of the brachial plexus.

In many patients, the cancer has already spread beyond the original site by the time they have symptoms and seek medical attention. Common sites of metastasis include the bone, such as the spine (causing back pain and occasionally spinal cord compression) and the brain

what is lung cancer

Lung cancer is a cancer of the lungs characterized by the presence of malignant tumours. Most commonly it is bronchogenic carcinoma (about 90%). Lung cancer is the most lethal of cancers worldwide, causing up to 3 million deaths annually. Only one in ten patients diagnosed with this disease will survive the next five years. Although lung cancer was previously an illness that affected predominately men, the lung cancer rate for women has been increasing in the last few decades, which has been attributed to the rising ratio of female to male smokers. More women die of lung cancer than any other cancer, including breast cancer, ovarian cancer and uterine cancers combined.[1]

Current research indicates that the factor with the greatest impact on risk of lung cancer is long-term exposure to inhaled carcinogens. The most common means of such exposure is tobacco smoke.

Treatment and prognosis depend upon the histological type of cancer and the stage (degree of spread). Possible treatment modalities include surgery, chemotherapy, and/or radiotherapy.