Monthly Archives: July 2015

General Information About Non-Small Cell Lung Cancer (NSCLC)

NSCLC is any type of epithelial lung cancer other than small cell lung cancer (SCLC). The most common types of NSCLC are squamous cell carcinoma, large cell carcinoma, and adenocarcinoma, but there are several other types that occur less frequently, and all types can occur in unusual histologic variants. Although NSCLCs are associated with cigarette smoke, adenocarcinomas may be found in patients who have never smoked. As a class, NSCLCs are relatively insensitive to chemotherapy and radiation therapy compared with SCLC. Patients with resectable disease may be cured by surgery or surgery followed by chemotherapy. Local control can be achieved with radiation therapy in a large number of patients with unresectable disease, but cure is seen only in a small number of patients. Patients with locally advanced unresectable disease may achieve long-term survival with radiation therapy combined with chemotherapy. Patients with advanced metastatic disease may achieve improved survival and palliation of symptoms with chemotherapy, targeted agents, and other supportive measures.

Estimated new cases and deaths from lung cancer (NSCLC and SCLC combined) in the United States in 2014:[1]

Lung cancer is the leading cause of cancer-related mortality in the United States.[1] The 5-year relative survival rate from 1995 to 2001 for patients with lung cancer was 15.7%. The 5-year relative survival rate varies markedly depending on the stage at diagnosis, from 49% to 16% to 2% for patients with local, regional, and distant stage disease, respectively.[2]

NSCLC arises from the epithelial cells of the lung of the central bronchi to terminal alveoli. The histological type of NSCLC correlates with site of origin, reflecting the variation in respiratory tract epithelium of the bronchi to alveoli. Squamous cell carcinoma usually starts near a central bronchus. Adenocarcinoma and bronchioloalveolar carcinoma usually originate in peripheral lung tissue.

Anatomy of the respiratory system.

Smoking-related lung carcinogenesis is a multistep process. Squamous cell carcinoma and adenocarcinoma have defined premalignant precursor lesions. Before becoming invasive, lung epithelium may undergo morphological changes that include the following:

Dysplasia and carcinoma in situ are considered the principal premalignant lesions because they are more likely to progress to invasive cancer and less likely to spontaneously regress.

In addition, after resection of a lung cancer, there is a 1% to 2% risk per patient per year that a second lung cancer will occur.[3]

NSCLC is a heterogeneous aggregate of histologies. The most common histologies include the following:

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Non-Small Cell Lung Cancer Treatment - National Cancer ...

Sickle-cell disease (SCD), also known as sickle-cell anaemia (SCA) and drepanocytosis, is a hereditary blood disorder, characterized by an abnormality in the oxygen-carrying haemoglobin molecule in red blood cells. This leads to a propensity for the cells to assume an abnormal, rigid, sickle-like shape under certain circumstances. Sickle-cell disease is associated with a number of acute and chronic health problems, such as severe infections, attacks of severe pain ("sickle-cell crisis"), and stroke, and there is an increased risk of death.

Sickle-cell disease occurs when a person inherits two abnormal copies of the haemoglobin gene, one from each parent. Several subtypes exist, depending on the exact mutation in each haemoglobin gene. A person with a single abnormal copy does not experience symptoms and is said to have sickle-cell trait. Such people are also referred to as carriers.

The complications of sickle-cell disease can be prevented to a large extent with vaccination, preventive antibiotics, blood transfusion, and the drug hydroxyurea/hydroxycarbamide. A small proportion requires a transplant of bone marrow cells.

Almost 300,000 children are born with a form of sickle-cell disease every year, mostly in sub-Saharan Africa, but also in other parts of the world such as the West Indies and in people of African origin elsewhere in the world. In 2013 it resulted in 176,000 deaths up from 113,000 deaths in 1990.[1] The condition was first described in the medical literature by the American physician James B. Herrick in 1910, and in the 1940s and 1950s contributions by Nobel prize-winner Linus Pauling made it the first disease where the exact genetic and molecular defect was elucidated.

Sickle-cell disease may lead to various acute and chronic complications, several of which have a high mortality rate.[2]

The terms "sickle-cell crisis" or "sickling crisis" may be used to describe several independent acute conditions occurring in patients with SCD. SCD results in anemia and crises that could be of many types including the vaso-occlusive crisis, aplastic crisis, sequestration crisis, haemolytic crisis, and others. Most episodes of sickle-cell crises last between five and seven days.[3] "Although infection, dehydration, and acidosis (all of which favor sickling) can act as triggers, in most instances, no predisposing cause is identified."[4]

The vaso-occlusive crisis is caused by sickle-shaped red blood cells that obstruct capillaries and restrict blood flow to an organ resulting in ischaemia, pain, necrosis, and often organ damage. The frequency, severity, and duration of these crises vary considerably. Painful crises are treated with hydration, analgesics, and blood transfusion; pain management requires opioid administration at regular intervals until the crisis has settled. For milder crises, a subgroup of patients manage on NSAIDs (such as diclofenac or naproxen). For more severe crises, most patients require inpatient management for intravenous opioids; patient-controlled analgesia devices are commonly used in this setting. Vaso-occlusive crisis involving organs such as the penis[5] or lungs are considered an emergency and treated with red-blood cell transfusions. Incentive spirometry, a technique to encourage deep breathing to minimise the development of atelectasis, is recommended.[6]

Because of its narrow vessels and function in clearing defective red blood cells, the spleen is frequently affected.[7] It is usually infarcted before the end of childhood in individuals suffering from sickle-cell anemia. This spleen damage increases the risk of infection from encapsulated organisms;[8][9] preventive antibiotics and vaccinations are recommended for those lacking proper spleen function.

Splenic sequestration crises are acute, painful enlargements of the spleen, caused by intrasplenic trapping of red cells and resulting in a precipitous fall in hemoglobin levels with the potential for hypovolemic shock. Sequestration crises are considered an emergency. If not treated, patients may die within 12 hours due to circulatory failure. Management is supportive, sometimes with blood transfusion. These crises are transient, they continue for 34 hours and may last for one day.[10]

Acute chest syndrome (ACS) is defined by at least two of the following signs or symptoms: chest pain, fever, pulmonary infiltrate or focal abnormality, respiratory symptoms, or hypoxemia.[11] It is the second-most common complication and it accounts for about 25% of deaths in patients with SCD, majority of cases present with vaso-occlusive crises then they develop ACS.[12][13] Nevertheless, about 80% of patients have vaso-occlusive crises during ACS.

Read more here:
Sickle-cell disease - Wikipedia, the free encyclopedia

Description

An in-depth report on the causes, diagnosis, treatment, and prevention of non-small cell lung cancer (NSCLC).

Lung cancer - non-small cell; NSCLC

Risk:

Treatment:

Although lung cancer accounts for only 15% of all newly-diagnosed cancers in the United States, it is the leading cause of cancer death in U.S. men and women. It is more deadly than colon, breast, and prostate cancers combined. About 160,000 patients die from lung cancer each year. Death rates have been declining in men over the past decade, and they have about stabilized in women.

The lungs are two spongy organs surrounded by a thin moist membrane called the pleura. Each lung is composed of smooth, shiny lobes: the right lung has three lobes, and the left has two. About 90% of the lung is filled with air. Only 10% is solid tissue.

The major features of the lungs include the bronchi, the bronchioles, and the alveoli. The alveoli are the microscopic blood vessel-lined sacks in which oxygen and carbon dioxide gas are exchanged.

Lung cancer develops when genetic mutations (changes) occur in a normal cell within the lung. As a result, the cell becomes abnormal in shape and behavior, and reproduces endlessly. The abnormal cells form a tumor that, if not surgically removed, invades neighboring blood vessels and lymph nodes and spreads to nearby sites. Eventually, the cancer can spread (metastasize) to locations throughout the body.

The two major categories of lung cancer are small cell lung cancer and non-small cell lung cancer. Most lung cancers are non-small cell cancer, the subject of this report. Less common cancers of the lung are known as carcinoids, cylindromas, and certain sarcomas (cancer in soft tissues). Some experts believe all primary lung cancers come from a single common cancerous (malignant) stem cell. As it copies itself, that stem cell can develop into any one of these cancer types in different people.

See the article here:
Non-small cell lung cancer | University of Maryland ...