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Omid Hospital
Mashhad University of Medical Sciences
Cancer(medical term: malignantneoplasm) is a class of diseases in which a group of cells display uncontrolled growth (division beyond the normal limits), invasion (intrusion on and destruction of adjacent tissues), and sometimes metastasis (spread to other locations in the body via lymph or blood). These three malignant properties of cancers differentiate them from benign tumors, which are self-limited, and do not invade or metastasize. Most cancers form a tumor but some, like leukemia, do not. The branch of medicine concerned with the study, diagnosis, treatment, and prevention of cancer is oncology.
Cancer may affect people at all ages, even fetuses, but the risk for most varieties increases with age.Cancer causes about 13% of all deaths.According to the American Cancer Society, 7.6 million people died from cancer in the world during 2007.Cancers can affect all animals.
Nearly all cancers are caused by abnormalities in the genetic material of the transformed cells. These abnormalities may be due to the effects of carcinogens, such as tobacco smoke, radiation, chemicals, or infectious agents. Other cancer-promoting genetic abnormalities may be randomly acquired through errors in DNA replication, or are inherited, and thus present in all cells from birth. The heritability of cancers are usually affected by complex interactions between carcinogens and the host's genome. New aspects of the genetics of cancer pathogenesis, such as DNA methylation, and microRNAs are increasingly recognized as important.
Genetic abnormalities found in cancer typically affect two general classes of genes. Cancer-promoting oncogenes are typically activated in cancer cells, giving those cells new properties, such as hyperactive growth and division, protection against programmed cell death, loss of respect for normal tissue boundaries, and the ability to become established in diverse tissue environments. Tumor suppressor genes are then inactivated in cancer cells, resulting in the loss of normal functions in those cells, such as accurate DNA replication, control over the cell cycle, orientation and adhesion within tissues, and interaction with protective cells of the immune system.
Diagnosis usually requires the histologic examination of a tissue biopsy specimen by a pathologist, although the initial indication of malignancy can be symptoms or radiographicimaging abnormalities. Most cancers can be treated and some cured, depending on the specific type, location, and stage. Once diagnosed, cancer is usually treated with a combination of surgery, chemotherapy and radiotherapy. As research develops, treatments are becoming more specific for different varieties of cancer. There has been significant progress in the development of targeted therapy drugs that act specifically on detectable molecular abnormalities in certain tumors, and which minimize damage to normal cells. The prognosis of cancer patients is most influenced by the type of cancer, as well as the stage, or extent of the disease. In addition, histologicgrading and the presence of specific molecular markers can also be useful in establishing prognosis, as well as in determining individual treatments.
Source: http://en.wikipedia.org/wiki/Cancer
http://www.chemotherapy.com/understanding_cancer/understanding_cancer.jsp
http://www.aicr.org.uk/?source=Adwords&gclid=CIPWkeDMgZoCFQEEZgodR2pWFg
| Treating Cancer With Chemotherapy |
Chemotherapy is a treatment used for cancer. There are many different chemotherapy drugs available, which can be used in different ways according to the type of cancer you have, how advanced it is and your general health.
Chemotherapy is a treatment that is used at various stages of cancer. It's used to treat solid tumors (cancerous lumps) affecting organs such as the breast or bowel, as well as blood cancers such as leukemia.
You can have chemotherapy at one or more of the following stages.
- Before surgery (this is known as neo-adjuvant therapy) to shrink a tumor so that it's easier to remove. This is normally used for large tumors or those that are strongly attached to surrounding tissue.
- After surgery (this is known as adjuvant therapy) to make sure that any cancerous cells left in the body after removal of a tumor are killed. This makes it less likely that the cancer will come back.
- In advanced cancer to shrink the tumor, or to slow the progress of the disease and prolong life.
You will have your own chemotherapy treatment planned by an oncologist, a doctor who specializes in treating cancer.
Some people have chemotherapy at the same time as radiotherapy (this is called chemo radiotherapy). In a few tumors this can be more effective than having either treatment separately.
When cancer has spread to other organs, it may not be possible to cure it completely. In this case, the aim of chemotherapy may be to slow the progress of the disease and to extend the period of good-quality life for as long as possible. This is called palliative chemotherapy.
High-dose chemotherapy is used to treat some types of cancer, particularly leukemia. This treatment also destroys many of the cells from the body's immune system (which protects the body from infection) and it has to be followed by a bone marrow transplant to replace the tissue damaged by the high-dose drugs.
The type of chemotherapy drugs used depends on a number of things, including:
- the type of cancer
- where the cancer started
- whether the cancer has spread to other parts of your body
- your general health
You will be monitored regularly throughout your course of chemotherapy by physical examination, X-rays or scans, as well as blood and urine tests.
All chemotherapy drugs work by attacking cells that are dividing rapidly. Normal cells divide at a rate that is tightly controlled. However, in cancer cells, this process goes wrong, leading to uncontrolled production of new cells and the formation of a tumor or blood cancer.
Most chemotherapy drugs affect the DNA in cancer cells. DNA is the chemical that stores the genetic information in a cell. It controls what a cell does, including how it divides. By affecting the DNA, most chemotherapy drugs interfere with the division of cancer cells and may cause the cancer to die back completely. Your doctor will give you more information about your chemotherapy drugs.
Several newer treatment options are more experimental and may only be available in clinical trials. They include:
- angiogenesis inhibitors, which prevent the growth of blood vessels inside a tumor, starving it of blood
- immune therapies, which help the body's immune system to attack cancer cells; they include monoclonal antibodies, which target cancer cells and stimulate the body to destroy them
Most chemotherapy drugs are fed directly into the bloodstream. This is called intravenous chemotherapy. There are several ways in which chemotherapy drugs can be introduced into your blood.
- A drip in a vein in your arm or the back of your hand.
- A central line - a thin tube that leads from the skin of your chest to a main vein near your heart. A central line can be left in place for a few months, so that medicines can be injected through it when you need them.
- A peripherally inserted central catheter (PICC) line - a thin tube placed into a vein in the crook of your arm and threaded through the vein until it's in a vein near your heart. A PICC line can stay in place for a few months.
- A portable catheter ("portacath") - a thin tube that is put into a vein in your arm or chest.
- An infusion pump - a portable pump that attaches to a PICC line or a central line. This feeds the correct dose of chemotherapy drugs into your bloodstream over a few days.
Other ways to have chemotherapy drugs include:
- tablets or capsules - this is becoming a more common way of having chemotherapy (this is known as oral chemotherapy)
- injections into the area around your spinal cord (intrathecal injections)
- injections into a body cavity such as your bladder (intracavity chemotherapy)
- creams for skin cancers
You can have chemotherapy in the form of tablets or creams at home, whereas you will usually need to have injections or infusions in hospital. It's sometimes possible to be given chemotherapy at home. These sessions may take between 30 minutes and a few hours at a time.
Combinations of two or more drugs are often used for chemotherapy.
Duration of chemotherapy treatment
The length of chemotherapy treatment depends on your type of cancer, how much it has spread through your body, the types of drugs used, the severity of side-effects and how successful the treatment is.
Chemotherapy is usually given in cycles. Cycles are sessions of treatment with rest periods in between to allow your body to recover from any side-effects. A course of chemotherapy is made up of several cycles. Several cycles of treatment are needed because chemotherapy only attacks cells that are actively dividing. At any one time, some cancer cells will be resting, and they may not be killed until a later round of treatment.
If you have high-dose chemotherapy followed by a bone-marrow transplant, you will need to stay in hospital for several weeks.
Fertility and chemotherapy
There is a risk of becoming infertile (not being able to become pregnant or father children) after chemotherapy and in some women it can bring on an early menopause. It's important that you discuss these risks with your doctor before you start the treatment.
Different chemotherapy drugs cause different side-effects, so it's important to discuss your specific treatment with your doctor.
| Effects of chemotherapy on your everyday life |
Some people manage to continue with their lives as normal during chemotherapy. A small number of people even feel better as the symptoms of their cancer improve. But for many people chemotherapy can have a big impact on everyday life. In particular, tiredness often prevents people from carrying on working full time or doing normal levels of physical activity.
The chemotherapy side-effects of sickness and diarrhea can make the contraceptive pill less effective. Women having chemotherapy shouldn't try to become pregnant during treatment because the chemotherapy drugs can damage a developing baby.
It's important to weigh up the risks of side-effects with the benefits of having the treatment, and to ask your doctor for advice.
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source: http://hcd2.bupa.co.uk/fact_sheets/html/chemotherapy.html#1
http://www.chemotherapy.com/treating_with_chemo/treating_with_chemo.jsp
| Side-effects of chemotherapy |
The treatment can be physically exhausting for the patient. Current chemotherapeutic techniques have a range of side effects mainly affecting the fast-dividing cells of the body. Important common side-effects include (dependent on the agent):
Chemotherapy doesn't only target cancer cells,
but any cells that divide rapidly. This includes those in the bone marrow and skin, hair-producing cells, and the cells that line the mouth and digestive system. Damage to these healthy cells during chemotherapy may produce various side-effects, including:
- tiredness
- feeling sick and vomiting
- diarrhea or constipation
- loss of appetite
- loss of hair
- getting infections more easily
- sore mouth, mouth ulcers and changes to your sense of taste
- numbness or "pins and needles" in your hands and feet
- changes in hearing - some people get tinnitus (a ringing sound in the ears)
- skin changes - skin may become dry and discoloured
Most chemotherapy side-effects are temporary and will eventually pass once the treatment is completed. It's important to weigh up the benefits of chemotherapy against the risks of side-effects.
Many of the side-effects can be controlled using other medicines. For example, sickness can be reduced using anti-emetic (anti-sickness) medicines.
Tiredness is the most common side-effect of chemotherapy treatment, and it can last a long time. This may be frustrating because you will feel tired even if you are resting. Most people get back to their normal energy levels within about six months, but it can take longer.
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