CA125   
A blood protein that can be measured and is an important tumor market in ovarian cancer.

Cancer   
A group of diseases in which malignant cells grow out of control and spread to other parts of the body.

Cancer-in-situ   
The stage where the cancer is still confined to the tissue in which it started.

Candidiasis    
A common fungal infection.

Carcinoembryonic antigen    (CEA)
A blood tumor marker.

Carcinogen   
A substance that causes cancer. For example, nicotine in cigarettes is a carcinogen that causes lung cancer.

Carcinoma   
A kind of cancer that starts in the skin or the lining of organs.

Cardiomegaly    
An enlargement of the heart.

CAT scan   
Computerized axial tomography, or CT scan, an x-ray test that produces cross-sectional images of the body that are more detailed than standard x-rays.

Catheter   
A hollow silicone tube inserted and secured into a large vein in the chest for long-term administration of drugs or nutrients.

Cell   
The fundamental structural and functional unit of living organisms.

Cellulitis    
The inflammation of an area of the skin (epithelial layer).

Central venous catheter   
A special intravenous tubing that is surgically inserted into a large vein near the heart and exits from the chest or abdomen. The catheter allows medications, fluids, or blood products to be given and blood samples to be taken.

Cervical carcinoma    
A cancer of the cervix (part of the uterus opening)

Cervical nodes    
Lymph nodes in the neck.

Chemotherapy    
The treatment of cancer with drugs.

Chest tube   
A flexible tube inserted between the ribs and into the space surrounding the lungs in order to drain air or fluid.

Chest x-ray   
A picture of the chest taken with x-rays.

Chondrosarcoma   
A malignant tumor of cartilage usually occurring near the ends of the long bones.

Chronic   
Persisting over a long period of time.

Clinical trials    
Also called “clinical studies.” Research studies with people. Each trial tries to answer specific scientific questions and to find better ways to prevent, detect, or treat diseases or to improve care.

Colonoscopy   
A procedure for looking at the colon or large bowel through a lighted, flexible tube.

Colostomy   
A surgical procedure by which an opening is created between the colon and the outside of the abdomen to allow stool to be emptied into a collection bag.

Colposcopy   
Examination of the vagina and cervix with an instrument called a colposcope.

Combination chemotherapy   
More than one (generally between 2 and 4) different anticancer drugs used together to treat cancer.

Community Clinical Oncology Program    (CCOP)
A program funded by the National Cancer Institute.

Complementary medicin   
Healing practices other than those of mainstream medicine.

Complication   
An undesired additional problem related to a disease process or to a treatment for a disease.

Computerized tomography   (CT scan)
A series of detailed pictures of areas inside the body; the pictures are created by a computer linked to an x-ray machine. Also called computed axial tomography (CAT scan).

Conformal radiation therapy    (3D-CRT)
Radiation treatment that uses sophisticated computer software to conform or shape the distribution of radiation beams to the 3-dimensional shape of the diseased prostate, sparing damage to normal tissue in the vicinity of treatment.

Congestive heart failure   
A buildup of fluid in the lungs and/or extremities (especially the legs). This occurs because the heart cannot pump the blood adequately.

Consent form   
A document that provides key facts about a clinical trial. This includes information about the study agent, tests that study participants may have, and possible benefits and risks. Although all participants in a clinical trial must sign a consent form, they can leave the study at any time. As a trial proceeds, there may be new consent forms.

Counseling   
Discussions with a health professional regarding assistance with life situations, behavior, relationships, and feelings.

CPR   
Cardiopulmonary resuscitation, a technique to revive a person after the heart has stopped.

CT/CAT scan   
A test using computers and x-rays to create images of various parts of the body.

Curative treatment   
A treatment intended to eradicate disease.

Cyst   
An accumulation of fluid or semisolid material within a sac.

Cystitis   
An inflammation of the bladder.

Cytotoxic Drug   
A drug that kills specific cells in the body.