Cachexia: General lack of nutrition or wasting that occurs in the course of some cancer cases.

Calcifications: Small calcium deposits within the breast, singly or in clusters, that are usually found by mammography. These are also called microcalcifications and macrocalcifications. They are a sign of change within the breast that may be monitored by additional, periodic mammograms, or by immediate or delayed biopsy. They may be caused by benign (non-cancerous) breast conditions or by breast cancer.

Cancer: A general term for more than 100 diseases in which malignant (cancerous) cells develop.  Some exist quietly within the body for years without causing a problem. Others are aggressive, rapidly forming tumors that may invade and destroy surrounding tissue and travel through the lymph system or bloodstream to distant areas of the body.

Cancer care team: The group of health care professionals who cooperate in the diagnosis, treatment, after-care, and counseling of people with cancer. The breast cancer care team may include any or all of the following and others: primary care physician and/or gynecologist, pathologist, oncology specialists (medical oncologist, radiation oncologist), surgeon, nurse, oncology nurse specialist, oncology social worker. Whether the team is linked formally or informally, there is usually one person who takes the job of "referee" (See also case manager).

Cancer cell: A cell that divides and reproduces abnormally and can spread throughout the body. (See also metastasis).

Cancer-related checkup: A routine health examination for cancer in persons without obvious signs or symptoms of cancer. The goal of the cancer-related check-up is to find the disease, if it exists, at an early stage, when chances for cure are greatest. Clinical breast examinations, Pap smears, and skin examinations are examples of methods used in cancer-related check-ups. (See also detection, screening).

Capecitabine: Brand name, Xeloda. Drug used to treat metastatic breast cancer in patients who have not responded well to chemotherapy that included Taxol (generic name, paclitaxel) and an anthracycline (such as Adriamycin or doxorubicin). Capecitabine works by converting to a substance called 5-fluorouracil in the body. In some patients, capecitabine helps shrink tumor size by killing cancer cells. 

Capsule formation: Scar tissue that may form around a breast (or other type of) implant as the body reacts to the foreign object. Sometimes called a contracture.

Carcinogen: Any substance that causes cancer or helps cancer to grow. For example, tobacco smoke contains many carcinogens that have been proven to dramatically increase the risk of lung cancer.

Carcinoma: A malignant (cancerous) tumor that begins in the lining layer (epithelial cells) of organs. At least 80% of all cancers are carcinomas, and almost all breast cancers are carcinomas.

Carcinoma in situ: An early stage of cancer, in which the tumor is still only in the structures of the organ where it first developed, and the disease has not invaded other parts of the organ or spread (metastasized). Most in situ carcinomas are highly curable.

Case manager: The member of a cancer care team, usually a nurse or oncology nurse specialist, who coordinates the patient's care throughout diagnosis, treatment, and recovery. The case manager is a new concept that provides a guide through the complex system of health care by helping cut through red tape, getting responses to questions, managing crises, and connecting the patient and family to needed resources.

Catheter: A thin tube through which fluids can enter and leave the body.

CT scan (CAT scan): See computed tomography.

Cell: The basic unit of all living organisms. Organs are clusters of cells that have developed specialized tasks. Cells replace themselves by splitting and forming new cells (mitosis). The processes that control formation of new cells and death of old cells are disrupted in cancer.

Chemoprevention: Prevention or reversal of disease using drugs, chemicals, vitamins, or minerals. While this idea is not currently widely used, it is a very promising area of study. The Breast Cancer Prevention Trial has shown that the drug tamoxifen can prevent some cases of breast cancer among women with high risk of this disease. However, the drug has some serious side effects.

Chemotherapy: Treatment with drugs to destroy cancer cells. Chemotherapy is often used in addition to surgery or radiation to treat cancer when metastasis (spread) is proven or suspected, when the cancer has come back (recurred), or when there is a strong likelihood that the cancer could recur. (See also adjuvant therapy).

Chest wall invasion: The growth of breast cancer into the pectoralis (chest wall) muscle; typically occurs with larger advanced cancers or with smaller cancers initially located near the pectoralis muscle. 

Chromosome: A DNA molecule that contains genes arranged end-to-end.  In humans and plants, chromosomes are located in the cell's nucleus (center).

Clear margins: Pathological term used to describe an adequate amount of normal tissue that is surgically removed along with the breast cancer. 

Cleavage view: (also called "valley view") It is a mammogram view of the most medial portions of the breasts. This is the portion of breast tissue "in the valley" between the two breasts.

Clinical breast examination (CBE): A physical examination of the breast conducted by a health care professional such as a physician, physician assistant, nurse or nurse practitioner.  The purpose of CBE is to detect lumps or suspicious breast changes that may warrant further attention.

Clinical trial: An organized research study conducted with people or animals to find new methods to prevent, detect, diagnose, or treat a disease.  Clinical trials often compare a new treatment to a standard one.

Combination chemotherapy: The use of more than one drug to treat cancer.

Complete blood count (CBC): The number of red blood cells, white blood cells, and platelets in a sample of blood.  Also called blood count.

Computed tomography: An imaging procedure in which multiple x-rays are taken of a part of the body to produce cross-sectional images of internal organs. Except for injection of a dye (needed in some but not all cases), this is a painless procedure that can be performed in an outpatient clinical setting. It is often referred to as a CT or CAT scan.

Contracture: A capsule or shell of dense scar-like tissue that may form around a breast implant. (See also capsule formation).

Core needle biopsy: Removal of tissue or fluid from a lump or cyst with a large needle and syringe.

Cyst: A fluid-filled sac that is usually benign (non-cancerous). The fluid can be removed for analysis. (See needle aspiration).

Cytology: The study or examination of cells by a cyto-pathologist using a microscope to determine whether they are cancerous or benign (non-cancerous).

Cytotoxic: Toxic to cells; cell-killing.

Updated: August 2006