Cancer gives no signs or symptoms that exclusively explain the nature of disease. But however, if you have any of the symptoms mentioned below, you should consult your doctor/cancer specialist as soon as possible.
Here are some symptoms of common cancer:
*Continual Cough or blood tinged saliva- These could be symptoms of cancer in the head, lung (bronchitis) or neck. Even a general cough can become a symptom of cancer if it lasts for more than a month. If that is the case, you should consult your doctor immediately.
* Changes in bowel habits- If you observe changes in your bowel movement or feel abnormality even after you have had a bowel movement should see a doctor.
* Blood in stools- A doctor must always investigate the blood in the stools. These can be observed through X-rays. But sometimes, when the source is known, these steps may not be necessary.
*Unexplained anemia- Anemia is a condition when the actual number of RBCs (Red Blood Cells) is lower than the desired number. Your doctor must investigate anemia also.
Anemia can be caused my many cancers, but the bowel cancer can cause iron deficiency. Your upper and lower intestinal tracts should be either evaluated by endoscopy or x-rays.
* Breast discharge or breast lump-All breast lumps need to be investigated thoroughly. A negative mammogram isn't sufficient to evaluate breast lumps. Generally, diagnosis requires biopsy or needle aspiration. Most of these forms of discharges and lumps may be causes of cancer, so if there is blood discharge from only one nipple, then it must be evaluated as soon as possible.
* Testicle lumps- Most of the men having cancer have uncomfortable or painless lump in their testicles. Some may even have enlarged testicles. The lumps and other conditions like swollen and infectious veins need to be continuously evaluated.
Cancer is caused by several ways. Sometimes, doctors have to battle the disease using several methods at once, and sometimes they use one method step wise of sequentially.
Cancer can be treated by a number of ways, thanks to improvement and success of modern treatments. There are basically four method of treatment of cancer. Chemotherapy, surgery, radiation therapy and biological therapy. In some cases, clinical trials may prove effective but everything depends on the type of cancer the person suffers from. There are other ways of treatment also which are not approved by the FDA and which are often given in countries other than USA.
When initially you’re diagnosed with cancer, the specialist/doctor will explain you how he will go with the treatment processes. But before that, he may also give you the treatment options. Generally a good doctor always gives you the best treatment which is based on the type of cancer you’re suffering from. Along with the treatment options, he or she will also give you details on how far its spread and the treatment duration etc.
But everything depends on your decision which usually depends on doctor’s opinion, alternative methods, information, treatment process and details gathered from specialists.
The actual goal of the treatment process is the complete removal of cancer without any adverse or side effects to the body. But the effect is often limited in the case of radiation therapy or by surgery due to toxicity of other tissues in the system. In fact, radiation can often lead to damage of normal tissues. Till date, there hasn’t been any 100 % effective cure for cancer, as cancer is a class of diseases. Radiation therapy is used to destroy cancer cells with X-rays or particles from radioactive elements such as cobalt 60.
Cause and Treatment for Cancer
Lung cancer - major factors
Lung cancer mainly on the occurrence of lung cancer smoking, occupational (in close contact with asbestos, radon gas, mustard gas, polycyclic aromatic hydrocarbons compounds, chlorine ether, chromium, nickel, inorganic arsenic compounds, as well as radiation, etc.), air pollution (the air pollution contains a large number of motor vehicle exhaust, burning waste) factors. There are other factors: dietary vitamin A and other analogues (vitamin A) in the content related to the occurrence of lung cancer, chronic lung diseases (such as chronic bronchitis, pulmonary tuberculosis), genetic factors.
The incidence of lung cancer is very complex factors. However, the two major factors ca be summarized as below:
First, environmental carcinogens factors.
With industrial development, air pollution has become a major problem, such as nitrosamines, asbestos, chrome, nickel, mustard gas, arsenic, bitumen, oil and other emissions…… spread in the air, the water enters the human body has become an important factor carcinogenic ;
Second, the individual factors to smoking is the most important factor.
Smoking index greater than 400 and obviously the incidence of lung cancer, smoking index for smoke daily count by the number of years of smoking. Some scholars study, smokers than non-smokers of lung cancer 8.8 times the rate. Tobacco-specific carcinogenic substances containing N-nitroso drop smoke pH, it is a Central nitrosamines, after activation, can be carcinogenic substances, carcinogenic mutations performance.
Lung Cancer - Causes
The main causes of lung cancer (and cancer in general) include carcinogens (such as those in tobacco smoke), ionizing radiation, and viral infection.This exposure causes cumulative changes to the DNA in the tissue lining the bronchi of the lungs (the bronchial epithelium).As more tissue becomes damaged, eventually a cancer develops
Smoking
Smoking, particularly of cigarettes, is by far the main contributor to lung cancer.
In the United States, smoking is estimated to account for 87% of lung cancer cases (90% in men and 85% in women). Among male smokers, the lifetime risk of developing lung cancer is 17.2%. Among female smokers, the risk is 11.6%. This risk is significantly lower in non-smokers: 1.3% in men and 1.4% in women. Cigarette smoke contains over 60 known carcinogens 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 smokes as well as the amount smoked increases the person's chance of developing lung cancer. If a person stops smoking, this chance steadily decreases as damage to the lungs is repaired and contaminant particles are gradually removed. Across the developed world, almost 90% of lung cancer deaths are caused by smoking. In addition, there is evidence that lung cancer in never-smokers has a better prognosis than in smokers, and that patients who smoke at the time of diagnosis have shorter survival than those who have quit.
Passive smoking—the inhalation of smoke from another's smoking—is a cause of lung cancer in non-smokers. Studies from the U.S., Europe, the UK, and Australia have consistently shown a significant increase in relative risk among those exposed to passive smoke. Recent investigation of sidestream smoke suggests it is more dangerous than direct smoke inhalation.
Radon gas
Radon is a colorless and odorless gas generated by the breakdown of radioactive radium, which in turn is the decay product of uranium, found in the earth's crust. The radiation decay products ionize genetic material, causing mutations that sometimes turn cancerous. Radon exposure is the second major cause of lung cancer after smoking. 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. The United States Environmental Protection Agency (EPA) estimates that one in 15 homes in the U.S. has radon levels above the recommended guideline of 4 picocuries per liter (pCi/L) (148 Bq/m³). Iowa has the highest average radon concentration in the United States; studies performed there have demonstrated a 50% increased lung cancer risk with prolonged radon exposure above the EPA's action level of 4 pCi/L.
Asbestos
Asbestos can cause a variety of lung diseases, including lung cancer. There is a synergistic effect between tobacco smoking and asbestos in the formation of lung cancer.[10] In the UK, asbestos accounts for 2–3% of male lung cancer deaths. Asbestos can also cause cancer of the pleura, called mesothelioma (which is different from lung cancer).
Viruses
Viruses are known to cause lung cancer in animals and recent evidence suggests similar potential in humans. Implicated viruses include human papillomavirus, JC virus, simian virus 40 (SV40), BK virus and cytomegalovirus. These viruses may affect the cell cycle and inhibit apoptosis, allowing uncontrolled cell division.
Originally from Wikipedia.org
Cancer - Causes
Main article: Carcinogenesis
Cancer is a diverse class of diseases which differ widely in their causes and biology. The common thread in all known cancers is the acquisition of abnormalities in the genetic material of the cancer cell and its progeny. Research into the pathogenesis of cancer can be divided into three broad areas of focus. The first area of research focuses on the agents and events which cause or facilitate genetic changes in cells destined to become cancer. Second, it is important to uncover the precise nature of the genetic damage, and the genes which are affected by it. The third focus is on the consequences of those genetic changes on the biology of the cell, both in generating the defining properties of a cancer cell, and in facilitating additional genetic events, leading to further progression of the cancer.
Chemical carcinogens
Cancer pathogenesis is traceable back to DNA mutations that impact cell growth and metastasis. Substances that cause DNA mutations are known as mutagens, and mutagens that cause cancers are known as carcinogens. Particular substances have been linked to specific types of cancer. Tobacco smoking is associated with lung cancer and bladder cancer. Prolonged exposure to asbestos fibers is associated with mesothelioma.
Many mutagens are also carcinogens, but some carcinogens are not mutagens. Alcohol is an example of a chemical carcinogen that is not a mutagen. Such chemicals are thought to promote cancers through their stimulating effect on the rate of cell mitosis. Faster rates of mitosis leaves less time for repair enzymes to repair damaged DNA during DN replication, increasing the likelihood of a genetic mistake. A mistake made during mitosis can lead to the daughter cells receiving the wrong number of chromosomes (see aneuploidy ).
Decades of research have demonstrated the strong association between tobacco use and cancers of many sites, making it perhaps the most important human carcinogen. Hundreds of epidemiological studies have confirmed this association. Further support comes from the fact that lung cancer death rates in the United States have mirrored smoking patterns, with increases in smoking followed by dramatic increases in lung cancer death rates and, more recently, decreases in smoking followed by decreases in lung cancer death rates in men.
Ionizing radiation
Sources of ionizing radiation, such as radon gas, can cause cancer. Prolonged exposure to ultraviolet radiation from the sun can lead to melanoma and other skin malignancies.
Infectious diseases
Furthermore, many cancers originate from a viral infection; this is especially true in animals such as birds, but also in humans, as viruses are responsible for 15% of human cancers worldwide. The main viruses associated with human cancers are human papillomavirus, hepatitis B and hepatitis C virus, Epstein-Barr virus, and human T-lymphotropic virus. Experimental and epidemiological data imply a causative role for viruses and they appear to be the second most important risk factor for cancer development in humans, exceeded only by tobacco usage. The mode of virally-induced tumors can be divided into two, acutely-transforming or slowly-transforming. In acutely transforming viruses, the viral particles carry a gene that encodes for an overactive oncogene called viral-oncogene (v-onc), and the infected cell is transformed as soon as v-onc is expressed. In contrast, in slowly-transforming viruses, the virus genome is inserted, especially as viral genome insertion is an obligatory part of retroviruses, near a proto-oncogene in the host genome. The viral promoter or other transcription regulation elements in turn cause overexpression of that proto-oncogene, which in turn induces uncontrolled cellular proliferation. Because viral genome insertion is not specific to proto-oncogenes and the chance of insertion near that proto-oncogene is low, slowly-transforming viruses have very long tumor latency compared to acutely-transforming viruses, which already carry the viral oncogene.
Hepatitis viruses, including hepatitis B and hepatitis C, can induce a chronic viral infection that leads to liver cancer in 0.47% of hepatitis B patients per year (especially in Asia, less so in North America), and in 1.4% of hepatitis C carriers per year. Liver cirrhosis, whether from chronic viral hepatitis infection or alcoholism, is associated with the development of liver cancer, and the combination of cirrhosis and viral hepatitis presents the highest risk of liver cancer development. Worldwide, liver cancer is one of the most common, and most deadly, cancers due to a huge burden of viral hepatitis transmission and disease.
Advances in cancer research have made a vaccine designed to prevent cancer available. In 2006, the US FDA approved a human papilloma virus vaccine, called Gardasil. The vaccine protects against four HPV types, which together cause 70% of cervical cancers and 90% of genital warts. In March 2007, the US CDC Advisory Committee on Immunization Practices (ACIP) officially recommended that females aged 11-12 receive the vaccine, and indicated that females as young as age 9 and as old as age 26 are also candidates for immunization.
In addition to viruses, researchers have noted a connection between bacteria and certain cancers. The most prominent example is the link between chronic infection of the wall of the stomach with Helicobacter pylori and gastric cancer.
Hormonal imbalances
Some hormones can act in a similar manner to non-mutagenic carcinogens in that they may stimulate excessive cell growth. A well-established example is the role of hyperestrogenic states in promoting endometrial cancer.
Immune system dysfunction
HIV is associated with a number of malignancies, including Kaposi's sarcoma, non-Hodgkin's lymphoma, and HPV-associated malignancies such as anal cancer and cervical cancer. AIDS-defining illnesses have long included these diagnoses. The increased incidence of malignancies in HIV patients points to the breakdown of immune surveillance as a possible etiology of cancer. Certain other immune deficiency states (e.g. common variable immunodeficiency and IgA deficiency) are also associated with increased risk of malignancy.
Heredity
Most forms of cancer are "sporadic", and have no basis in heredity. There are, however, a number of recognised syndromes of cancer with a hereditary component, often a defective tumor suppressor allele. Famous examples are:
- certain inherited mutations in the genes BRCA1 and BRCA2 are associated with an elevated risk of breast cancer and ovarian cancer
- tumors of various endocrine organs in multiple endocrine neoplasia (MEN types 1, 2a, 2b)
- Li-Fraumeni syndrome (various tumors such as osteosarcoma, breast cancer, sof tissue sarcoma, brain tumors) due to mutations of p53
- Turcot syndrome (brain tumors and colonic polyposis)
- Familial adenomatous polyposis an inherited mutation of the APC gene that leads to early onset of colon carcinoma.
- Hereditary nonpolyposis colorectal cancer (HNPCC, also known as Lynch syndrome) can include familial cases of colon cancer, uterine cancer, gastric cancer, and ovarian cancer, without a preponderance of colon polyps.
- Retinoblastoma, when occurring in young children, is due to a hereditary mutation in the retinoblastoma gene.
- Down syndrome patients, who have an extra chromosome 21, are known to develop malignancies such as leukemia and testicular cancer, though the reasons for this difference are not well understood.
Other causes
A few types of cancer in non-humans have been found to be caused by the tumor cells themselves. This phenomenon is seen in Sticker's sarcoma, also known as canine transmissible venereal tumor. The closest known analogue to this in humans is individuals who have developed cancer from tumors hiding inside organ transplants.
Originally from Wikipedia.org
