What is Cancer?

Cancer is a group of many different diseases that have some important effects in common. Cancer affects our cells, the basic unit of the body to live. In order to understand cancer, it is important to know how normal cells become cancerous.

The body is made up of many types of cells. Normally, as cells grow, they divide and reproduce to maintain the body healthful and working appropriately. Nevertheless, sometimes the process goes uncontrolled and cells continue dividing when it is not necessary. The mass of extra cells forms a growth or tumor. Some types of cells are more prone to abnormal growth that others. Tumors can be classified as benign or malignant. Benign tumors are not cancerous. They can be generally removed, and in most cases, they do not reappear. The cells in benign tumors do not extend to other parts of the body. Most important is that benign tumors are rarely a death threat.

Malignant tumors are cancerous. Cells in malignant tumors are abnormal and divide without control nor order. These cancerous cells can invade and destroy tissue around them. In addition, cancerous cells can separate from the malignant tumor and enter the blood torrent or the lymphatic system vessels (two of the blood vessel systems that bathe and feed all body organs). This process, called metastasis, is how the cancer extends from the original tumor to other parts of the body to form new tumors.

What are some of the symptoms and common signs of cancer?

Cancer can have a variety of symptoms. These are some of them:

• changes to intestine and bladder functions,
• wounds that do not heal,
• hemorrhages or unusual secretions,
• thickening or nodules in the breasts or any other part of the body,
• indigestion or difficulty when swallowing,
• persistent cough or hoarseness

When these or other symptoms happen, they are not sure signs of cancer. The symptoms can be caused by infections, benign tumors or other problems. It is important to consult with your doctor if you have any of these symptoms or if you are worried about other body changes or how you feel. Only a doctor can make a diagnosis. Don't wait to feel pain: cancer in its early phase generally does not cause any pain. If symptoms are present, a doctor can prescribe several tests and/or a biopsy. A biopsy is the most trustworthy way to know if a medical problem is cancer. During a biopsy, the doctor removes a tissue sample of the abnormal area. The tissue is then examined under a microscope to identify cancerous cells.

How is cancer treated?

Cancer can be treated with surgery, radiation therapy, chemotherapy, hormonal therapy or biological therapy. The doctor can use one method or a combination of methods. The treatment option depends on the type and location of cancer, if the disease has extended, age of the patient and general health, and other factors. An important option for people with cancer is to take part in clinical studies. Doctors direct clinical studies to know the effectiveness and secondary effects of new treatments.

Through research, doctors learn new forms of treating cancer that can be more effective than conventional therapy. In some studies, all patients receive the new treatment. In others, doctors compare different therapies giving to a group of patients the new treatment and conventional therapy to the other group. Research like this, has lead to significant advances in the treatment of cancer. The people who take part in these studies have the first opportunity to benefit from treatments that have shown to be promising. These people also make an important contribution to medical science.

Can cancer be prevented?

Cancer is developed gradually as result of a complex mixture of factors related with the atmosphere, lifestyle, and inheritance. Scientists have identified many factors that increase the probability of developing cancer. Some people are more sensible than others to factors that can cause cancer. Many cancer cases can be prevented by not using derivatives of tobacco, avoiding harmful rays of the sun, and choosing foods with less fat and more fiber. In addition, alcohol and exposure to certain chemicals and/or radiation can increase the risk of a person of developing cancer. Many risk factors can be avoided. Others, such as inherited factors, are inevitable. It is important to know them, but it is also important to remember that not all people with a factor of particular risk to develop cancer really suffers the illness; in fact, it does not happen to most. People who have a greater probability of developing cancer can be instructed to protect themselves avoiding where possible risk factors and attending regular checkups, so that, if cancer is developed, most probably it will be found early. It is probable that the treatment is more effective when cancer is discovered early.

For more information

For more information about cancer you may contact Cancer Information Service. This service provides precise and updated information on cancer, to patients and their relatives, health professionals, and public in general.

The Cancer Information Service (CIS) can be contacted at 1-800-422-6237, it is a toll free call.

You can also contact us by Internet at:
http://www.cancernet.nci.nih.gov
http://cancertrials.nci.nih.gov