Autologous Cellular Immunotherapy (ACI): An approach that uses live human cells to re-engage the patient's own immune system. The goal of autologous cellular immunotherapy (ACI) is to turn the immune system "back on" to elicit a specific long-lasting response against cancer.

Adenocarcinoma: Cancer that starts in the glandular tissue, such as the prostate.

Androgen: Any male sex hormone. The major androgen is testosterone.

Androgen-Independent: Term for prostate cancer cells that no longer respond to hormone therapy; also known as hormone refractory or castrate resistant.

Antigen: A substance that causes the body's immune system to react. This reaction often involves production of antibodies. For example, the immune system's response to antigens that are part of bacteria and viruses helps people resist infections. Cancer cells have certain antigens that can be found by laboratory tests. They are important in cancer diagnosis and in watching response to treatment. Other cancer cell antigens play a role in immune reactions that may help the body's resistance against cancer.

Antigen Delivery Cassette™ Technology: Dendreon's proprietary approach for antigen modification. The cassette allows for the engineering or modification of tumor antigens to augment the uptake and processing of the antigen by dendritic cells to increase the potency of an immune response.

Antigen-Presenting Cells (APC): A cell that shows antigen on its surface to other cells of the immune system. This is an important part of an immune response.

Active Cellular Immunotherapy (ACI): An approach that uses live human cells to re-engage the patient's own immune system. The goal of active cellular immunotherapy is to turn the immune system "back on" to elicit a specific long-lasting response against cancer.

Benign Prostatic Hyperplasia (or Hypertrophy) (BPH): Non-cancerous enlargement of the prostate that may cause problems with urination such as trouble starting and stopping the flow. Also referred to as BPH.

Biologics License Application (BLA): If clinical trials show a treatment is safe and effective, the sponsor of the treatment may submit a BLA to the U.S. Food and Drug Administration (FDA) requesting FDA approval for the treatment. The BLA includes:

  • The exact chemical makeup of the drug or biologic
  • Results of animal studies
  • Results of clinical trials
  • How the drug or biologic is made, processed, and packaged
  • Quality control standards

Once the FDA receives the BLA from the sponsor, the formal Biologics/Product License Application Review Process begins. According to the FDA, a BLA is a request for permission to introduce, or deliver for introduction, a biologic product into interstate commerce.

Biopsy: The removal of a sample of tissue to see whether cancer cells are present. There are several kinds of biopsies. In a fine needle aspiration biopsy (sometimes used to check pelvic lymph nodes), a very thin needle is used to draw out fluid and cells. In a core biopsy, a larger needle is used to remove a thin cylinder of tissue.

Cancer: Cancer develops when cells in the body begin to grow out of control. Normal cells grow, divide, and die. Instead of dying, cancer cells continue to grow and form new abnormal cells. Cancer cells often travel to other body parts where they grow and replace normal tissue. This spreading process is called metastasis. When cancer spreads or metastasizes, it is still named after the part of the body where it started. For example, if prostate cancer spreads to the bones, it is still prostate cancer, not bone cancer. Some cancers, such as blood cancers, do not form a tumor. Not all tumors are cancer. A tumor that is not cancer is called benign and does not grow and spread the way cancer does.

Castrate Resistant Prostate Cancer (CRPC): Term for prostate cancer cells that no longer respond to hormone therapy; also known as hormone refractory prostate cancer.

Chemotherapy: Treatment with drugs to destroy cancer cells. Chemotherapy is often used with surgery or radiation to treat cancer when the cancer has spread, when it has come back (recurred), or when there is a strong chance that it could recur.

Clinical Trial, Clinical Study: A type of research study that tests how well new medical approaches work in people. These studies test new methods of screening, prevention, diagnosis, or treatment of a disease.

Digital Rectal Examination (DRE): An examination in which a doctor inserts a lubricated, gloved finger into the rectum to feel for abnormalities.

Free-PSA Ratio: Indicates how much PSA circulates alone or unbound in the blood and how much is bound together with other blood proteins. For total PSA results in the borderline range, a low percent free-PSA (25% or less) means that a prostate cancer is more likely to be present and suggests the need for a biopsy. Also known as percent-free PSA.

Glands: A cell or group of cells that produce and release substances used nearby or in another part of the body. A prostate is a gland.

Gleason Score (GS) or Gleason Grade: The most often used prostate cancer grading system is called the Gleason system. This system assigns a Gleason grade ranging from 1 through 5 based on how similar the cancer cells look compared to how normal prostate cells are arranged in the prostate gland. Because prostate cancers often have areas with different grades, a grade is assigned to the two areas that make up most of the cancer. These two grades are added together to give a Gleason score between 2 and 10.

Hormone: A chemical substance released into the body by the endocrine glands such as the thyroid, adrenal, or ovaries. The substance travels through the bloodstream and sets in motion various body functions. Testosterone and estrogen are examples of male and female hormones.

Hormone Refractory Prostate Cancer (HPRC): Term for prostate cancer cells that no longer respond to hormone therapy; also known as androgen independent or castrate resistant prostate cancer.

Hormone Therapy (HT): Treatment with hormones, with drugs to interfere with hormone production or hormone action (such as LHRH-agonists), or the surgical removal of hormone-producing glands. Hormone therapy may kill cancer cells or slow their growth.

Immune System: The complex group of organs and cells that defends the body against infections and other diseases.

Lymph, Lymphatic Fluid: Clear fluid that flows through the lymphatic vessels and contains cells known as lymphocytes. These cells are important in fighting infections and may also have a role in fighting cancer.

Lymph Nodes, Lymph Glands: Small bean-shaped collections of immune system tissue such as lymphocytes, found along lymphatic vessels. They help fight infections and also have a role in fighting cancer.

Lymphatic System: The tissues and organs (including lymph nodes, spleen, thymus, and bone marrow) that produce and store lymphocytes (cells that fight infection) and the channels that carry the lymph fluid. The entire lymphatic system is an important part of the body's immune system. Invasive cancers sometimes penetrate the lymphatic vessels (channels) and spread (metastasize) to lymph nodes.

Lymphocyte: A type of white blood cell. Lymphocytes have a number of roles in the immune system, including the production of antibodies and other substances that fight infection and diseases.

Malignant Tumor: A mass of cancer cells that may invade surrounding tissues or spread (metastasize) to distant areas of the body.

Metastasis: The spread of cancer from one part of the body to another. A tumor formed by cells that have spread is called a “metastatic tumor” or a “metastasis.” The metastatic tumor contains cells that are like those in the original (primary) tumor. The plural form of metastasis is metastases (meh-TAS-tuh-SEEZ).

Oncologist: A doctor with special training in the diagnosis and treatment of cancer.

Palliative Treatment: Treatment that relieves symptoms, such as pain, but is not expected to cure the disease. Its main purpose is to improve the patient's quality of life. Sometimes chemotherapy and radiation are used in this way.

Pathologist: A physician who specializes in diagnosis and classification of diseases by laboratory tests such as examination of tissue and cells under a microscope. The pathologist determines whether a tumor is benign or cancerous, and, if cancerous, the exact cell type and grade.

Perineal Prostatectomy: Surgery to remove the prostate through an incision made between the scrotum and the anus.

Phase 1 Clinical Trial: The first step in testing a new treatment in humans. These studies test the best way to give a new treatment (for example, by mouth, intravenous infusion, or injection) and the best dose. The dose is usually increased a little at a time in order to find the highest dose that does not cause harmful side effects. Because little is known about the possible risks and benefits of the treatments being tested, phase 1 trials usually include only a small number of patients who have not been helped by other treatments.

Phase 1/2 Clinical Trial: A trial to study the safety, dosage levels, and response to a new treatment.

Phase 2 Clinical Trial: A study to test whether a new treatment has an anticancer effect (for example, whether it shrinks a tumor or improves blood test results) and whether it works against a certain type of cancer.

Phase 2/3 Clinical Trial: A trial to study response to a new treatment and the effectiveness of the treatment compared with the standard treatment regimen.

Phase 3 Clinical Trial: A study to compare the results of people taking a new treatment with the results of people taking the standard treatment (for example, which group has better survival rates or fewer side effects). In most cases, studies move into Phase 3 only after a treatment seems to work in phases 1 and 2. Phase 3 trials may include hundreds of people.

Phase 4 Clinical Trial: After a treatment has been approved and is being marketed, it is often studied in a Phase 4 trial to evaluate side effects that were not apparent in the Phase 3 trial. Thousands of people are involved in a Phase 4 trial.

Prostate: A gland in the male reproductive system. The prostate surrounds the part of the urethra (the tube that empties the bladder) just below the bladder, and produces a fluid that forms part of the semen.

Prostate Specific Antigen (PSA): A substance produced by the prostate that may be found in an increased amount in the blood of men who have prostate cancer, benign prostatic hyperplasia, or infection or inflammation of the prostate.

Prostatectomy: An operation to remove part or all of the prostate. Radical (or total) prostatectomy is the removal of the entire prostate and some of the tissue around it.

Radiation Oncologist: A doctor who specializes in using radiation to treat cancer.

Radiation Therapy: Treatment with high-energy rays (such as x-rays) to kill or shrink cancer cells. The radiation may come from outside of the body (external radiation) or from radioactive materials placed directly in the tumor (internal or implant radiation). Radiation therapy may be used to reduce the size of a cancer before surgery, to destroy any remaining cancer cells after surgery, or as the main treatment. In advanced cancer cases, it may also be used as palliative treatment.

Radical Prostatectomy: Surgery to remove the entire prostate gland, the seminal vesicles and nearby tissue.

Recombinant DNA Technology: Made through genetic engineering, which is also called gene splicing. By putting animal or plant genes into the genetic material of bacteria or yeast cells, these microorganisms can be turned into "factories" to make proteins for medical uses.

Refractory: No longer responsive to a certain therapy.

Screening: The search for disease, such as cancer, in people without symptoms. For example, screening measures for prostate cancer include digital rectal examination and the PSA blood test. Screening may refer to coordinated programs in large populations.

Sipuleucel-T: An investigational product that may represent the first in a new class of autologous cellular immunotherapies.

Staging: Performing exams and tests to learn the extent of the cancer within the body, especially whether the disease has spread from the original site to other parts of the body. It is important to know the stage of the disease in order to plan the best treatment. TNM: A system for describing the extent of cancer in a patient’s body. T describes the size of the tumor and whether it has invaded nearby tissue, N describes any lymph nodes that are involved, and M describes metastasis (spread of cancer from one body part to another).

T-Cells: A type of lymphocyte that combats disease by killing antigen-bearing cells.

Tumor: An abnormal lump or mass of tissue. Tumors can be benign (not cancerous) or malignant (cancerous).

Urologist: A doctor who specializes in diseases of the urinary organs in females and the urinary and sex organs in males.

Watchful Waiting: Closely monitoring a patient's condition but withholding treatment until symptoms appear or change. Also called observation.

White Blood Cells: Refers to a blood cell that does not contain hemoglobin. White blood cells include lymphocytes, neutrophils, eosinophils, macrophages, and mast cells. These cells are made by bone marrow and help the body fight infection and other diseases.

Sources include: American Cancer Society Glossary of Terms located at and the National Cancer Institute Dictionary of Cancer Terms located at