STOMACH CANCER: is deadly to body system

Cancer Information

Introduction

Stomach cancer also refers to gastric cancer is a disease characterized by abnormal growth of cells in the stomach. The incidence of stomach cancer has decreased dramatically since the early 20th century in countries where refrigeration has replaced other methods of food preservation such as salting, smoking, and pickling. Stomach cancer rates remain high in countries where these processes are still used extensively.

Causes and symptoms

Ninety-five percent of malignant stomach cancers develop from epithelial cells lining the stomach. These tumours are called adenocarcinomas. Other stomach cancers can develop from the surrounding immune cells, hormone-producing cells, or connective tissue. Multiple risk factors have been identified that increase a person's probability of developing this cancer. 

These include a diet high in salted, smoked, or pickled foods, tobacco and alcohol use, or a family history of stomach cancer. Infection by the bacterium Helicobacter pylori, which can cause significant damage to gastric tissues and is a cause of peptic ulcers, can also lead to stomach cancer. Other factors that may increase the risk of stomach cancer to varying degrees are previous stomach surgery, blood type A, advanced age (60–70 years), or chronic stomach inflammation. 

Males develop stomach cancer at approximately twice the rate of females. Rare disorders such as pernicious anemia or Menetrier disease and congenital disorders that lead to increased risk for colorectal cancer may also increase stomach cancer risk.

The symptoms of stomach cancer are prevalent in many other illnesses and may include abdominal pain or discomfort, unexplained weight loss, vomiting, poor digestion, or visible swelling in the abdomen.

Diagnosis

No specific laboratory test for stomach cancer exists, and the disease is therefore usually diagnosed through a combination of visual means. A physician can inspect the lining of the stomach with a flexible, lens-containing tube called an endoscope. The endoscope can also be used to take samples from potentially cancerous tissues for biopsy. These samples are examined under a microscope for signs of cancer. An endoscope may also be modified with a special probe that emits sound waves in the stomach, which allows the physician to create an image of the stomach wall. X rays are also employed, usually after the patient has swallowed a barium compound that coats the stomach and provides better image contrast. Other imaging techniques such as computed tomography (CT) scans and magnetic resonance imaging (MRI) are also used, especially when the cancer is believed to have spread.

          

Once stomach cancer has been diagnosed, its stage is determined. The stage is an indicator of how far the cancer has progressed. Staging for stomach cancer is complicated and is based on a combination of how far the cancer has grown through the stomach wall and on the number of lymph nodes affected, if any. Stage 0 stomach cancer is also called carcinoma in situ and is confined to the epithelial cells that line the stomach. Stage I and stage II cancers have spread into the connective tissue or muscle layers that underlie the epithelial cells, but they have reached fewer than six nearby lymph nodes. Stage III and IV cancers are more advanced and may have metastasized to distant tissues.

A very high percentage of individuals survive stomach cancer for at least five years if the cancer is diagnosed very early, and many of them go on to live long, healthy lives. Unfortunately, only a small percentage of stomach cancers are identified and treated at such an early stage. At the time when most lower-stomach cancers are diagnosed, roughly half the patients survive for at least five years. Cancers of the upper stomach have a lower survival rate, and if the cancer has spread to distant tissues in the body, the survival rate is extremely low.

Treatment

Surgery is the only method available for curing stomach cancer, although radiation or chemotherapy may be used in conjunction with surgery or to relieve symptoms. If the cancer is localized, the cancerous portions of the stomach are removed in a procedure called a partial gastrectomy. In some cases, the entire stomach must be removed along with the spleen and nearby lymph nodes. Repair of the stomach generally requires permanent changes in dietary habits and may demand intravenous administration of vitamin supplements. 

          

If a cancer cannot be cured, surgery may still be used to relieve symptoms or digestive discomfort. Radiation therapy is sometimes used in conjunction with surgery to destroy any remaining cancer cells. When stomach cancer has spread to distant organs, chemotherapy may be required so that as many cancer cells as possible can be sought out and destroyed. Both radiation therapy and chemotherapy may produce several side effects such as vomiting and diarrhea.

Prevention

Stomach cancer cannot be completely prevented, but people can decrease their risk of disease by adopting a diet that is low in salted, smoked, and pickled foods and high in fruits and vegetables. Elimination of tobacco use and reduction in alcohol consumption also help lower risk. Research has indicated that prompt treatment of H. pylori infection can reverse gastric tissue damage, thereby reducing stomach cancer risk.

TESTICULAR CANCER:all you need to know about this cancer

Cancer Information

Introduction

Disease characterized by uncontrolled growth of cells within the testis, the reproductive organ that produces sperm. Although testicular cancer represents only 1 percent of all cancers, it is the most common malignancy for men between the ages of 20 and 34. It most often affects men between 15 and 39 years of age. In the United States, approximately 7,500 new cases are diagnosed each year.

Testicular cancers are broadly classified as seminomas or nonseminomas based on their appearance and other characteristics. About 30 percent of testicular cancers are seminomas, and they tend to respond well to treatment. Nonseminomas, including yolk-sac tumours, embryonal carcinomas, and choriocarcinomas, are generally less responsive to treatment than seminomas. Typically, more than one type of nonseminoma will be present within the same tumour.

    

Causes and symptoms

Most cases of testicular cancer arise in individuals who have no known risk factors for the disease. An important known risk factor is a developmental abnormality that consists of a failure of one or both testes to descend into the scrotum, which normally takes place around the time of birth. The abnormality, called cryptorchidism, occurs in up to 10 percent of one-year-old boys, and it is associated with a 5- to 10-fold increased risk of testicular cancer, even if the condition is corrected with surgery.

Testicular cancer is typically noticed by the patient as a painless lump in either testis. This lump can be associated with swelling of the scrotum, pain and discomfort in the scrotum, or a dull ache in the lower abdomen. Because these symptoms are not specific to cancer, they should be investigated by a physician.

Diagnosis and prognosis

The initial investigation of a suspicious lump may involve blood tests and imaging studies. Different types of testicular cancer are associated with an increase in specific substances in the blood, including alpha fetoprotein, human chorionic gonadotropin, and lactate dehydrogenase. Ultrasound may be used to determine the size and location of a tumour in a testis and may help distinguish cancer from a benign condition. Ultimately, diagnosis of cancer requires removal of the testis and examination of the tissue under a microscope.

The prognosis depends on the type of testicular cancer found and the extent to which it has spread. Both types tend to metastasize first to the local lymph nodes of the pelvis and subsequently to distant sites such as the lungs. Seminomas have a cure rate greater than 95 percent when detected early. Nonseminomas tend to spread more quickly and behave more aggressively than seminomas, but they can be cured in more than 90 percent of cases.

 A dramatic increase in the cure rate, particularly for patients with nonseminomas, has been achieved largely through improved chemotherapy introduced in the mid-1970s.

Treatment

As with many cancers, treatment involves a combination of surgery, chemotherapy, and radiation therapy, depending on the type and spread of the original cancer. Virtually all testicular cancer is diagnosed and treated initially by surgically removing the affected testis (orchiectomy). 

Fortunately, the removal of one testis usually does not affect fertility. If the cancer has spread into the pelvic region or beyond, radiation or chemotherapy may be added to the treatment. Seminomas tend to respond very well to radiation therapy alone, even after the cancer has spread into the pelvis. Nonseminomas often require the addition of chemotherapy.

Prevention

Undescended testes are usually moved into the scrotum surgically before puberty to help prevent the development of cancer. Otherwise, regular self-examination and physical examination by a physician for testicular cancer can lead to early detection, which provides the best opportunity for a cure

All you need to know about lung cancer

Cancer Information

The alveoli and capillaries in the lungs exchange oxygen for carbon dioxide. Imbalances in the exchange of these gases can lead to dangerous respiratory disorders, such as respiratory acidosis or hyperventilation. In addition, accumulation of fluid in the alveolar spaces can interfere with gas exchange, causing symptoms such as shortness of breath

Introduction

Disease characterized by uncontrolled growth of cells in the lungs. Lung cancer was first described by doctors in the mid-19th century. In the early 20th century it was considered relatively rare, but by the end of the century it was the leading cause of cancer-related death among men in more than 25 developed countries. In the United States it has surpassed breast cancer as the leading cause of death from cancer among women. This rapid increase is due mostly to the increased use of cigarettes since World War I.

Causes and symptoms

Lung cancer occurs primarily in persons between 45 and 75 years of age. In countries with a prolonged history of cigarette smoking, between 80 and 90 percent of all cases are caused by smoking. Heavy smokers have a greater likelihood of developing the disease than do light smokers. The risk is also greater for those who started smoking at a young age.

Passive inhalation of cigarette smoke (sometimes called second hand smoke) is linked to lung cancer in non smokers. In the early 1990s it was estimated that passive smoking caused some 2,500 to 3,300 lung cancer deaths each year in the United States, or about 2 percent of all U.S. lung cancer deaths. Other risk factors include exposure to radon gas and asbestos; smokers exposed to these substances run a greater risk of developing lung cancer than do non smokers. Uranium and pitchblende miners, chromium and nickel refiners, welders, and workers exposed to halogenated ethers also have an increased incidence, as do some workers in hydrocarbon-related processing, such as coal processors, tar refiners, and roofers. Lung cancer is rarely caused directly by inherited mutations.

Tumours can begin anywhere in the lung, but symptoms do not usually appear until the disease has reached an advanced stage or spread to another part of the body. The most common symptoms include shortness of breath, a persistent cough or wheeze, chest pain, bloody sputum, unexplained weight loss, and susceptibility to lower respiratory infections. In cases where the cancer has spread beyond the lungs, visible lumps, jaundice, or bone pain may occur.

Diagnosis

Lung cancers are often discovered during examinations for other conditions. Cancer cells may be detected in sputum; a needle biopsy may be used to remove a sample of lung tissue for analysis; or the large airways of the lungs (bronchi) can viewed directly with a bronchoscope for signs of cancer. Non invasive methods include X rays, computed tomography (CT) scans, positron emission tomography (PET) scans, and magnetic resonance imaging (MRI).

Most cases are usually diagnosed well after the disease has spread (metastasized) from its original site. For this reason, lung cancer has a poorer prognosis than many other cancers. Even when it is detected early, the five-year survival rate is about 50 percent.

Types of lung cancer

Once diagnosed, the tumour's type and degree of invasiveness are determined. There are two basic forms: small-cell carcinoma, which accounts for 20–25 percent of all cases, and non-small-cell carcinoma, which is responsible for the remainder.

Small-cell carcinoma

Small-cell carcinoma (SCLC), also called oat-cell carcinoma, is rarely found in people who have never smoked. It is characterized by cells that are small and round, oval, or shaped like oat grains. SCLC is the most aggressive type of lung cancer; because it tends to spread quickly before symptoms become apparent, the survival rate is very low.

Non-small-cell carcinomas

Non-SCLCs consist primarily of three types of tumour: squamous cell carcinoma, adenocarcinoma, and large-cell carcinoma.

Adenocarcinoma accounts for some 25 to 30 percent of cases worldwide, but it is the most common type of lung cancer in the United States. Cells of adenocarcinoma are cube- or column-shaped, and they form structures that resemble glands and are sometimes hollow. Tumours often originate in the smaller, peripheral bronchi. Symptoms at the time of diagnosis often reflect invasion of the lymph nodes, pleura, and both lungs or metastasis to other organs.

Some 25 to 30 percent of primary lung cancers are squamous cell carcinomas, also called epidermoid carcinomas. This tumour is characterized by flat, scale like cells, and it often develops in the larger bronchi of the central portion of the lungs. Squamous cell carcinoma tends to remain localized longer than other types and thus is generally more responsive to treatment.

About 10 percent of all lung cancers are large-cell carcinomas. There is some dispute as to whether these constitute a distinct type of cancer or are merely a group of unusual squamous cell carcinomas and adenocarcinomas. Large-cell carcinomas can begin in any part of the lung and tend to grow very quickly.

Treatment

As with most cancers, treatments for lung cancer include surgery, chemotherapy, and radiation. The choice of treatment depends on the patient's general health, the stage or extent of the disease, and the type of cancer. The type of treatment an individual patient receives may also be based on the results of genetic screening, which can identify mutations that render some lung cancers susceptible to specific drugs.

Surgery involves the removal of a cancerous segment (segmentectomy), a lobe of the lung (lobectomy), or the entire lung (pneumonectomy). Lung surgery is serious and can lead to complications such as pneumonia or bleeding. Although removal of an entire lung does not prohibit otherwise healthy people from ultimately resuming normal activity, the already poor condition of many patients' lungs results in long-term difficulty in breathing after surgery.

Radiation may be used alone or in conjunction with surgery—either before surgery to shrink tumours or following surgery to destroy small amounts of cancerous tissue. Radiation treatment may be administered as external beams or surgically implanted radioactive pellets (brachytherapy). Side effects include vomiting, diarrhoea, fatigue, or additional damage to the lungs. Chemotherapy uses chemicals to destroy cancerous cells, but these chemicals also attack normal cells to varying degrees, causing side effects that are similar to radiation therapy. An experimental technology that has shown promise in the treatment of lung cancer is microwave ablation, which relies on heat derived from microwave energy to kill cancer cells. Early studies in small subsets of patients have demonstrated that microwave ablation can shrink and possibly even eliminate some lung tumours.

Tissue from (left) a nonsmoker's lung and (right) a smoker's lung.

Prevention

The probability of developing lung cancer can be greatly reduced by avoiding smoking. Smokers who quit also reduce their risk significantly. Testing for radon gas and avoiding exposure to coal products, asbestos, and other airborne carcinogens also lowers risk.

BRAIN CANCER

Impulses travel up the spinal cord from sense organs to the brain for processing and then back to a muscle for action.

INTRODUCTION

the uncontrolled growth of cells in the brain. The term brain cancer refers to any of a variety of tumors affecting different brain cell types. Depending on the location and cell type, brain cancers may progress rapidly or slowly over a period of many years. Brain cancers are often difficult to treat, and complete cure is often unattainable.

Causes and symptoms

The causes of different brain cancers remain largely unknown. Unlike many other cancers, brain tumors seem to occur at random in the population and are not usually associated with known risk factors. However, exposure to ionizing radiation, such as during head X rays, does increase a person's risk of developing certain brain cancers, as does a suppressed immune system or family history of cancer. Symptoms of brain cancer vary widely depending on the location of the tumor. As the tumor grows, it might put pressure on nearby regions of the brain and thereby affect the functions controlled by those regions. Difficulty or changes in speech, hearing, vision, or motor functions can all indicate the presence of a brain tumor. Many brain tumors are initially discovered following chronic headaches, and in some cases seizures are associated with cancers of the brain. Symptoms may also include vomiting, nausea, or numbness in any part of the body.

Diagnosis and prognosis

If a brain tumor is suspected, a neurological exam is conducted to test general brain function. Further diagnosis usually utilizes imaging procedures such as X rays, computed tomography (CT) scans, and magnetic resonance imaging (MRI). The location and stage of a tumor can also be determined with positron emission tomography (PET) scans. The blood supply feeding a tumor can be assessed by using an X-ray procedure called angiography. A definitive diagnosis usually requires removal of brain tissue for analysis; often this is done during tumor-removal surgery. In other cases, a needle biopsy guided by the images generated by CT scans or MRI may be used to access the tumor.

Brain cancers are usually not diagnosed until symptoms have appeared, and survival rates vary widely, depending on type and location. Some are completely curable. Slow-growing cancers may progress for decades, whereas other types may be fatal within six to eight years. Average survival from some faster-growing tumors, however, averages no more than one year.

Treatment

Surgery is the most frequent approach to treating brain tumors. Such surgery may be curative for some cancers, but for others it may only relieve symptoms and prolong survival. In many cases, complete removal of the tumor is not possible.

Radiation therapy may be used to cure some brain cancers, but others do not respond to radiotherapy. Radiation generally works best with fast-growing types. Because radiation therapy typically involves X rays, which pose a risk to healthy brain tissue, it is important to minimize exposure to the normal cells surrounding the tumor. This is accomplished by employing special procedures that focus the radiation. For instance, a device called a gamma knife, which emits a highly controllable beam of radiation, may be used. Even when radiation is localized, however, radiotherapy can cause side effects such as vomiting, diarrhea, or skin irritation. Radiation to the brain may cause scar tissue to form and potentially cause future problems. Memory loss may also occur.

Chemotherapy is used for some brain tumors, but, owing to the brain's protective barrier, many chemotherapeutic agents cannot enter the brain from the bloodstream. Chemotherapy works best on fast-growing tumors, but it is generally not curative and causes side effects similar to radiation therapy. Both radiation therapy and chemotherapy are often used when a person's general health or the location of the tumor prevents surgery.

Prevention

In rare cases where a family history or a personal history of frequent head X rays suggests an increased risk of brain cancer, regular screening by a neurologist may allow developing cancers to be detected earlier. Otherwise, no means of preventing brain tumors are known.

The diagram shows the area affected by brain tumor