Diagnosing Lung Cancer

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Lung Cancer
Introduction
Lung cancer refers to an abnormal and uncontrollable growth of cells on either one or both the lungs. The abnormal cells are not in a position to carry out any of the normal functions of the lung cells and cannot grow into healthy lung tissues. As they develop, the abnormal cells may form tumors as well as interfere with the normal functioning of the lung, which is purifying oxygen that is used by the rest of the body via the blood. Lung cancer is one of the many cancer types that originate in the lungs. The lungs of human beings are spongy organs, two in number, located in the chest and are used to take in oxygen during inhalation and release carbon dioxide during exhalation.
Lung cancer has been identified as one of the leading causes of the cancer deaths in America among both women and men. The disease claims more lives every year than prostate, colon, breast cancers and ovarian. People who smoke have been identified as to be at the highest risk of having lung cancer. Lung cancer risk increases with the number and the length of time one takes cigarettes. If an individual stops smoking, regardless of the number of years he or she has been smoking, the individual can reduce the chances of getting lung cancer significantly. All the body cells are made up of DNA. Every time a mature cell undergoes division giving rise into two new cells, the DNA of the mother cell is exactly duplicated. The new cells are identical copies of the mother cell. In this way, the bodies of human beings continually replenish as old cells die and the new generation replaces them. Lung cancer starts with an error, commonly referred to as a mutation in the DNA of the cells. The DNA mutations are caused by several factors including the process of normal aging or through environmental factors like breathing in of asbestos fibers, radon gas exposure and cigarette smoking (Lane 2)
Studies and researchers indicate that it requires a series of mutations for a lung cancer cell to develop. Before the cell becomes fully cancerous, it can be precancerous. This way, the cell will still have some mutations but will still function as a normal lung cell. When a genetic mutated cell undergoes division, it passes on the abnormal genes to the new cells, which then divides into more and more cells with the mutation passing on and on. With every new mutation, the cell in the lung tissue becomes more and more mutated until it becomes ineffective in carrying out its functions as lung cell. At the later stages of lung cancer, some of the cells may move away from the original tumor and begin growing towards other body parts. Primary lung cancer begins from the lung when the cancer cells mutate to abnormal lung cells. In some cases, patients will experience their cancer move from the point of origin to another body part or sometimes metastasize in the lungs. This is commonly termed as secondary cancer as the lungs in this case are a secondary site in comparison to the original location of the cancer.
Lung Cancer Symptoms
Considering the high number of deaths that are reported as a result of lung cancer, it is important that any unusual physical feelings are reported to the doctor. In most cases, such unusual feelings are attributed to other conditions like bronchitis. Doctors on the other hand are required to check anything worrisome or unusual as they examine their patients. The symptoms and signs of lung cancer may take years to develop and in some cases may not appear until the condition is advanced. Symptoms of lung cancer in the chest include; pain in the shoulder, chest or back pains that are not related to coughing, intense or persistent coughing, shortness of breath, a change in sputum volume or color, voice becomes hoarse, each breath coming out with a harsh sound, lung problems that are recurrent such as pneumonia and bronchitis, coughing up mucus or phlegm, tinged with blood and coughing blood (Lane 2).
In cases where the original lung cancer has already spread, the patient may experience other symptoms in other parts of the body. Some of the common parts that lung cancer often spreads to include lymph nodes, bones, liver, brain, adrenal glands and other parts of the lungs. Lung cancer symptoms that may be witnessed in other body parts include; weight loss that cannot be explained or loss of appetite, muscle wasting, fatigue, bone, joint or headaches, bone fractures that are not related with any accidental injuries, neurological symptoms like memory loss or unsteady gait, facial and neck swelling, bleeding and general weakness.
Diagnosing Lung Cancer
In the case that a patient is suspected to have lung cancer using a screening procedure, a small section of the tissue from the affected part of the lung has to be examined under a microscope to locate cancer cells. This procedure, commonly termed as biopsy, is normally performed in several different ways. In some situations, the doctor performs it by passing a needle via the skin into the affected lungs to remove a sample of the tissue. This procedure is termed as a needle biopsy. In other situations, a biopsy may be performed during a bronchoscopy. Bronchoscopy is performed by inserting a small tube in the nose or mouth of the patient which goes all the way to the lungs (Jones 2). The tube that has light at the end enables the doctor to observe inside the lungs and remove a small sample of the tissue. After a patient has been diagnosed with this condition, examining the biopsied cells using the microscope also assists the doctors in determining the lung cancer type. It is important for the doctor to identify the specific type of lung cancer he or she is dealing with as it helps in determining the best possible treatment.
If a person has lung cancer symptoms, he should visit a GP who will inquire about the patients symptoms and general health. GPs may also examine the patients and require them to breath into a spirometer to measure the amount of air the patient breathes in and out. The patient may also be required to take a blood test so as to eliminate some of the possible diseases that the symptoms of the patients may be suggesting yet it is not lung cancer. This is common with chest infections. If a patient has been coughing blood and have other persistant lung cancer signs, he should be referred to a chest X-ray or to a specialist to directly check the chest conditions within a span of two weeks (Jones 2).
A chest X-ray is normally the initial test that is used in the diagnosis of lung cancer. Most of lung tumors appear on the X-rays like a white-grey mass. However, chest X-rays are not in a position to offer a definite diagnosis as they cannot distinguish between other similar conditions like lung abscess and cancer. In case the chest X –ray suggests that the patient may be having lung cancer, the patient should be referred to a chest conditions specialist. The specialists should conduct more tests to determine whether the patient has lung cancer as well as the type of lung cancer and how far it has spread.
A computerized tomography scan, often abbreviated as CT scan, is usually conducted following a chest X-ray. A CT scan makes use of a computer and X-rays to come up with detailed images of the inside of the patient’s body. The patient is usually given an injection before a CT scan of a contrast medium. This liquid contains a dye that enables the lungs to appear more clearly when scanned. The process is painless and last between 10 to 30 minutes (Jemal and Ward 120). A positron emission tomography-computerized tomography (PET-CT scan) may be conducted if the CT scan results indicate that the cancer the patient is having is at its early stages. This scan has the ability to show the location of the active cancer cells. This is important in the diagnosis and treatment of cancer especially at this early stage. Before the PET-CT scan, the patient is usually injected will a material that uses small amounts of radioactive. This process is also painless and lasts for between 30 to 60 minutes.
In cases where the CT scan indicates the possibility that the cancer may be affecting the central part of the chest, the patient has to have a bronchoscopy. This is a procedure which allows the physician to remove a small piece of the cells from inside the patient lungs. During bronchoscopy, a bronchoscope, which is a thin tube, is used to examine the lungs of a patient and take a cell sample called biopsy. The bronchoscope is normally passed through the patient’s nose or mouth, down his throat and into the airways of the lungs. The process may be uncomfortable and the patients are normally given a mild sedative to help them relax as well as local anesthetic to make the throat numb. The process is very quick and lasts for only few minutes. There are other different biopsy types in situations where the above mentioned biopsies are not available or the results are not clear. This includes surgical biopsy types such as mediastinoscopy or a thorascopy or a biopsy conducted using a needle inserted in the skin of the patient.
Percutaneous needle biopsy involves the removal of a piece of tissue from a suspected tumor and has it tasted at a laboratory to find out if it has cancerous cells. In this process, the CT scanner is used by the doctor to guide a needle to the location where the suspected tumor is through the skin. A local anaesthetic is normally used to numb that part of the skin and the needle passed through the patient’s skin and into his lungs. The needle is then used to remove a piece of the tissue that will be tasted (Jemal  and Ward 128).
Types and Staging of Lung Cancer
Lung cancer is classified broadly into two types, which include small cell lung cancers abbreviated as SCLC and non-small cell lung cancers abbreviated as (NSCLC). The classification is based on the microscope tumor cells appearance. The two types of lung cancers spread, grow and are treated differently hence it is important to distinguish them. SCLC is made up of approximately 10-15% of lung cancers. This type is the most aggressive as it grows rapidly compared to the other lung cancer types. SCLC is related strongly to cigarette smoking and it is estimated that only 1% of this type of cancer occurs in non-smokers. It metastasizes rapidly to other body parts and is most often identified after it has extensively spread (Ettinger 380)
The NSCLC has been identified as the most common type of lung cancer and it accounts for approximately 85-95% of all lung cancer cases. NSCLC can be classified into three major types depending on the cells type in the tumor. Adenocarcinomas are the most common NSCLC type and make up more than 40% of all the NSCL cases. While adenocarcinomas are strongly associated with smoking like the rest of the lung cancer types, this type is also witnessed in non-smokers and more specifically among women. Most of this type of lung cancer arises on the peripheral or outer areas of the lungs. They also spread to the lymph nodes and in some cases even beyond. Bronchioloalveolar carcinoma is adenocarcinoma subtype that often develops at different sites in the lungs after which they spread along the alveolar walls. It may also appear like pneumonia when observed using a chest X-ray. It increases in frequency and is mostly witnessed in women who don’t smoke and the Asian population.
Squamous cell carcinomas are the other type of NSCLC that was formerly more prevalent than adenocarcinomas. Currently, they account for approximately 25% of all the NSCLC cases. Also referred to as epidermoid carcinomas, the squamous cell cancers originate most often in the bronchi in the central area of the chest. This lung cancer type most always remains within the lung, spreading to the lymph nodes and grows to form a large cavity. Large cell carcinomas are the other NSCLC type that is in some situations known as undifferentiated carcinomas. It is the less common type accounting for approximately 10-15% percent of all lung cancer cases. It is known for its high tendency to spread to the lymph nodes in the lung and distant sites.
The other types of lung cancer may arise in the lung and such types are less common compared to SCLC and NSCLC and together make up only 5-10% of the lung cancers cases. These types include; Bronchial carcinoids which accounts for more than 5% of all the lung cancer cases. The tumors in this case are generally small of about 3 to 4 cm or less when diagnosed and mostly affect persons less than 40 years. Carcinoid tumors are not related to cigarette smoking, can metastasize and a small section of the tumors secrete substances that appear like hormones. Carcinoids grow and spread generally slow compared to bronchogenic cancers and can be detected early enough allowing it to be removed surgically. The other type are the cancers that support lung tissues like blood vessels, smooth muscles or cells that take part on the immune response rarely takes place in the lungs. Metastatic cancers resulting from other main tumors are often located in the lung. Tumors from the other parts of the body may spread and find their way to the lungs through the lymphatic system, the bloodstream or directly from organs that are close to the lung (Ettinger 390).
Stages of NON-Small Cell Lung Cancer
Small cell lung cancer can be placed into two major stages, the limited stage and the extensive stage. In the limited stage, cancer is normally found on one of the two sides of the chest, affecting only one part of the lung but may extend to the nearby lymph nodes. The extensive stage is where the lung cancer spreads to other chest regions or other body parts. This mode of staging was used in the past. Recently, the Joint Commission on Cancer has implemented a new lung cancer staging method which is more detailed and describes the small cell lung cancer using letters and Roman numerical. This is the same approach that is also used in the staging of non-small cancer while describing the spread and growth of cancer.
Staging is a means used to describe the location of cancer, where or if it has spread and whether it has gone to the extent of affecting other body parts. Physicians make use of diagnostic tests to determine the cancer stages hence the process of staging cannot be complete until all the required tests are done. Knowing the cancer stage helps the physicians to choose the kind of treatment that is best suited to give a patient and can also him help in predicting the prognosis of a patient which is the recovery chance of the patient. Generally, a lower stage number of lung cancer is associated with a better outcome. However, no physician is in a position to predict the time a patient will be able to live with lung cancer basing only on the stage of the lung cancer because the disease differs from one person to the other and treatment reacts differently for each tumor.
The stage of both non-small and small cell lung cancer is now described from Roman numerals I up to IV. One of the means of determining lung cancer staging is to find out if the cancer can be removed completely by a surgeon. In order to remove lung cancer completely, the surgeon must be able to remove the cancer as well as the surrounding lung tissue. Stage 0 is referred to as the situ disease which means that lung cancer is in place and has not yet developed and spread into the nearby tissues or outside the lung.
Stage I of lung cancer is when a small tumor has not yet spread to reach any lymph nodes and this makes it possible for it to be completely removed by a surgeon. This stage is further divided into two further stages; stage IA and stage IB. This further staging is based on the tumor size. Smaller tumors, like those more than 3 centimeters wide are placed in stage IA, while those tumors that are slightly larger, more than 3 cm but not more than 5 cm, are placed in IB ( Ryland. 150)
Stage II of lung cancer is also divided into two sub-stages; stage IIA and IIB. Stage IIA includes a tumor that is more than 5 cm but not more than 7 cm wide and has not spread to the lymph nodes that are near the lungs or a small tumor that is not more than 5cm wide and has spread to the lymph nodes that are nearby. On the other hand, the stage IIB describes a tumor that is larger than 5 cm but not more than 7 cm wide and has spread to the nearby lymph nodes or a tumor that is more than that is more than 7 cm wide that has or has not grown into the nearby lung structures but has not managed to spread to the nearby lymph nodes. In some cases, stage II tumors may be removed through surgery, while in other cases, more treatment is required.
Stage III lung cancer falls under two classifications which are stage IIIA and IIIB. For most of the IIIA cancer and almost all the stage IIIB cancers, the tumor is almost impossible to be removed. The lung cancer for example may have spread up to the lymph nodes at the chest center, which is outside the lung, or in some cases the tumor may have spread into the nearby structures within the lung. In either the two situations, the surgeon is less likely to remove the cancer completely now that a removal will require a bit by bit performance.
Stage IV lung cancer implies that the lung cancer has already spread to more than one area in the other lung, to the fluid around the heart or the lung, or other parts that are distant from the lung through the bloodstream. Once cancer has been released into the blood, it can spread to any part of the body, but in most cases, it spreads to the brain, liver, bones and adrenal glands. It is referred to as stage IVA when the cancer spreads within the chest or IVB when it manages to spread out of the chest.
This implies that surgery cannot be successfully used to treat lung cancer at stage III and IV. Lung cancer also prove impossible to remove in situations where it has spread up to the lymph nodes located above the collarbone, or incase the cancer has grown up to the vital structures found within the chest like the large blood vessels, the heart and the breathing tubes of the lungs. The best option in such a case is treatment. Recurrent cancer refers to cancer that comes back even after being treated. In case of recurr...