Important cancer questionsCancer is the second leading cause of death in this country. However, improvements in cancer detection, diagnosis, and treatment have increased the survival rate for many types of cancer.

 

 

 

Here are the commonly asked cancer questions:

What is cancer?
What causes cancer?
Can cancer be prevented?
What are some of the common signs and symptoms of cancer?
How is cancer treated?
Clinical Trials for Cancer
Does Cancer always cause pain?

What is cancer?

Cancer is a group of many related diseases that begin in cells, the body’s basic building blocks. To understand cancer, it is helpful to know what happens when normal cells become cancerous.

The body is made up of many types of cells. Normally, cells grow and divide to produce more cells as they are needed to keep the body healthy. Sometimes, this orderly process goes wrong. New cells form when the body does not need them, and old cells do not die when they should. The extra cells form a mass of tissue called a growth or tumor. Not all tumors are cancerous; tumors can be benign or malignant.

Benign tumors are not cancer. They can often be removed and, in most cases, they do not come back. Cells in benign tumors do not spread to other parts of the body. Most important, benign tumors are rarely a threat to life. On the other hand, Malignant tumors are cancer. Cells in malignant tumors are abnormal and divide without control or order. Cancer cells invade and destroy the tissue around them. Cancer cells can also break away from a malignant tumor and enter the bloodstream or lymphatic system.

Blood vessels include a network of arteries, capillaries, and veins through which the blood circulates in the body. The lymphatic system carries lymph and white blood cells through lymphatic vessels (thin tubes) to all the tissues of the body. By moving through the bloodstream or lymphatic system, cancer can spread from the primary (original) cancer site to form new tumors in other organs. The spread of cancer is called metastasis.

What causes cancer?

Scientists have learned that cancer is caused by changes in genes that normally control the growth and death of cells. Certain lifestyle and environmental factors can change some normal genes into genes that allow the growth of cancer. Many gene changes that lead to cancer are the result of tobacco use, diet, exposure to ultraviolet (UV) radiation from the sun, or exposure to carcinogens (cancer-causing substances) in the workplace or in the environment. Some gene alterations are inherited (from one or both parents). However, having an inherited gene alteration does not always mean that the person will develop cancer; it only means that the chance of getting cancer is increased. Scientists continue to examine the factors that may increase or decrease a person’s chance of developing cancer.

Although being infected with certain viruses, such as the human papillomavirus (HPV), hepatitis B and C (HepB and HepC), and human immunodeficiency virus (HIV), increases the risk of some types of cancer, cancer itself is not contagious. A person cannot catch cancer from someone who has this disease. Scientists also know that an injury or bruise does not cause cancer.


Can cancer be prevented?

Although there is no guaranteed way to prevent cancer, people can reduce their risk (chance) of developing cancer by:

  • Not using tobacco products
  • Choosing foods with less fat and eating more vegetables, fruits, and whole grains
  • Exercising regularly and maintaining a lean weight
  • Avoiding the harmful rays of the sun, using sunscreen, and wearing clothing that protects the skin
  • Talking with a doctor about the possible benefits of drugs proven to reduce the risk of certain cancers.

Although many risk factors can be avoided, some, such as inherited conditions, are unavoidable. Still, it is helpful to be aware of them. It is also important to keep in mind that not everyone with a particular risk factor for cancer actually gets the disease; in fact, most do not. People who have an increased likelihood of developing cancer can help protect themselves by avoiding risk factors whenever possible and by getting regular checkups so that, if cancer develops, it is likely to be found and treated early. Treatment is often more effective when cancer is detected early. Screening exams, such as sigmoidoscopy or the fecal occult blood test, mammography, and the Pap test, can detect precancerous conditions (which can be treated before they turn into cancer) and early-stage cancer.


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

Cancer can cause a variety of symptoms. Possible signs of cancer include the following:

  • New thickening or lump in the breast or any other part of the body
  • New mole or an obvious change in the appearance of an existing wart or mole
  • A sore that does not heal
  • Nagging cough or hoarseness
  • Changes in bowel or bladder habits
  • Persistent indigestion or difficulty swallowing
  • Unexplained changes in weight
  • Unusual bleeding or discharge

When these or other symptoms occur, they are not always caused by cancer. They can be caused by infections, benign tumors, or other problems. It is important to see a doctor about any of these symptoms or about other physical changes. Only a doctor can make a diagnosis. A person with these or other symptoms should not wait to feel pain because early cancer usually does not cause pain.

If symptoms occur, the doctor may perform a physical examination, order blood work and other tests, and/or recommend a biopsy. In most cases, a biopsy is the only way to know for certain whether cancer is present. During a biopsy, the doctor removes a sample of tissue from the abnormal area. A pathologist studies the tissue under a microscope to identify cancer cells.

How is cancer treated?

Cancer treatment can include surgery, radiation therapy, chemotherapy, hormone therapy, and biological therapy. The doctor may use one method or a combination of methods, depending on the type and location of the cancer, whether the disease has spread, the patient’s age and general health, and other factors. Because treatment for cancer can also damage healthy cells and tissues, it often causes side effects. Some patients may worry that the side effects of treatment are worse than the disease. However, patients and doctors generally discuss the treatment options, weighing the likely benefits of killing cancer cells and the risks of possible side effects. Doctors can suggest ways to reduce or eliminate problems that may occur during and after treatment.

Read Types of Cancer Treatments to learn more about the different treatments.

Are clinical trials (research studies) available? Where can people get more information about clinical trials?

Yes. Clinical trials are an important treatment option for many cancer patients. To develop new, more effective treatments, and better ways to use current treatments, the National Cancer Institute (NCI) is sponsoring clinical trials in many hospitals and cancer centers around the country. Clinical trials are a critical step in the development of new methods of treatment. Before any new treatment can be recommended for general use, doctors conduct clinical trials to find out whether the treatment is safe for patients and effective against the disease.

People interested in taking part in a clinical trial should talk with their doctor. Information about clinical trials is available from the NCI’s Cancer Information Service (CIS) (see below) at 1–800–4–CANCER and in the NCI booklet Taking Part in Cancer Treatment Research Studies, which is available at http://www.cancer.gov/publications on the Internet. This booklet describes how research studies are carried out and explains their possible benefits and risks. Further information about clinical trials is available at http://www.cancer.gov/clinicaltrials on the NCI’s Web site. The Web site offers detailed information about specific ongoing treatment trials as well as trials focused on prevention, screening, and diagnosis by linking to PDQ®, the NCI’s comprehensive cancer information database. The CIS also provides information from PDQ.

Does cancer always cause pain?

Having cancer does not always mean having pain. Whether a patient has pain may depend on the type of cancer, the extent of the disease, and the patient’s tolerance for pain. Most pain occurs when the cancer grows and presses against bones, organs, or nerves. Pain may also be a side effect of treatment. However, pain can generally be relieved or reduced with prescription medicines or over-the-counter drugs recommended by the doctor. Other ways to reduce pain, such as relaxation exercises, may also be useful. Pain should not be accepted as an unavoidable part of having cancer. It is important for patients to talk about pain so steps can be taken to help relieve it. The fear of addiction or “losing control” should not stop patients from taking pain medication. Patients who take medications for cancer pain, as prescribed by their doctor, rarely become addicted to them. In addition, changing the dose or type of medication can usually help if the patient has troublesome side effects.