Related Pages Cancer Advances In Focus Index 1

Yesterday

• In the mid-1970s, approximately 60 cases of colorectal cancer were diagnosed per 100,000 people in the United States, and approximately 51 percent of those diagnosed survived their disease at least 5 years.
• Surgery was a long-established treatment for colorectal cancer and could be curative for patients whose cancer had not spread. Yet, colorectal surgical techniques were continuously modified to improve their effectiveness and reduce related consequences. The "no touch isolation" surgical technique, for example, was developed as a way to limit the possible spread of cancer through the bloodstream during colorectal cancer surgery.
• Fluorouracil (5-FU)—an inhibitor of DNA synthesis—was first synthesized in 1957 and became the drug of choice for colorectal cancer treatment. There was little evidence that 5-FU—given alone as a single, large dose—prolonged survival; however, studies suggested that its use improved the quality of life for patients with advanced disease.
• Radiation therapy was used to manage the pain associated with rectal tumors. A variety of clinical trials conducted throughout the 1970s also explored whether various types of radiation therapy—preoperative radiation, adjuvant radiation (following surgery), and "endocavity" (direct contact) radiation—might prevent local cancer recurrence or improve survival in patients with rectal cancer.
• Studies provided strong evidence that environmental and lifestyle factors could influence risk for colorectal cancer. Some findings suggested that dietary factors—particularly meat and dietary fats—play a role in colorectal cancer development.

Today

• As of 2004, the latest year for which we have updated statistics, approximately 48 cases of colorectal cancer were diagnosed per 100,000 people in the United States. For both men and women, it is the third most commonly diagnosed cancer. Over the last 2 decades, colorectal cancer incidence rates have declined substantially, and, between 1984 and 2004, they fell by nearly 26 percent. This decline is likely due to increased colorectal cancer screening, which allows physicians to detect and remove colorectal polyps before they progress to cancer. About 65 percent of men and women diagnosed with colorectal cancer now survive their disease at least 5 years.
• Surgery continues to be the primary treatment for most colorectal cancer patients, but surgical techniques and survival after surgery have improved over the past 15 years. Surgery can cure about 90 percent of colorectal cancers when the disease is found early. Now, a National Cancer Institute (NCI)-funded study has confirmed that laparoscopic surgery—which is less invasive, usually requires less recovery time, and causes less pain for the patient than the conventional open surgical procedure—is a safe alternative to conventional surgery for patients with operable colon cancer. This technique is currently being investigated in patients with rectal cancer.
• Advances in chemotherapy have led to changes in treatment practice standards and improved survival for colorectal cancer patients. 5-FU remains the cornerstone chemotherapy drug for colorectal cancer; but, today it is administered as part of multidrug regimens. Researchers began testing drug combinations with 5-FU as early as the 1980s, and, in the mid-1990s, studies testing the combination of 5-FU and leucovorin as an adjuvant treatment found that this regimen improved the 5-year disease-free survival rate for patients with stage III colon cancer. Other agents combined with 5-FU/leucovorin are proving to be even more beneficial. For example, the addition of oxaliplatin to 5-FU/leucovovin—a treatment regimen known as FOLFOX 4—considerably prolongs disease-free survival when given as an adjuvant treatment to patients with stage III colon cancer. For patients with stage II or stage III rectal cancer, preoperative chemoradiation is usually administered, followed by surgery and postoperative chemotherapy.
• New, targeted therapies offer great promise in the fight against colorectal cancer. These therapies, including drugs and monoclonal antibodies, target specific biological processes used by cancers to grow and spread. Bevacizumab (Avastin), which is a monoclonal antibody that interferes with the development of new blood vessels to tumors, was recently approved as a targeted treatment for advanced colorectal cancer. When given with combination chemotherapy to patients with advanced disease, bevacizumab helped increase median overall survival and reduced the risk of death from colorectal cancer.
• Colorectal cancer prevention is a clinical imperative, and a key part of prevention involves the search for drugs that can safely and effectively block or reverse colorectal cancer development. One drug, celecoxib (Celebrex), has been the focus of several NCI co-sponsored clinical trials. Celecoxib blocks the actions of the enzyme cyclooxygenase-2 (COX-2), which is produced in response to inflammation and also by precancerous and cancerous tissues. The trials found that regular use of celecoxib significantly reduced the risk of developing precancerous polyps in the colon or rectum. Unfortunately, one NCI co-sponsored study also found that celecoxib was associated with an increased risk of cardiovascular events. Researchers are now working to understand how celecoxib might increase the risk of such events. In addition, laboratory studies are moving us toward "molecular prevention" by enabling us to identify biological markers that indicate which people are more likely to benefit from COX-2 inhibition and other "chemoprevention" approaches.
• Colorectal cancer screening is a vital part of prevention and early detection: Screening has clear clinical benefits, since colorectal cancer can take many years to develop and early detection of the disease greatly improves the chances of a cure. Screening also enables physicians to detect and remove colorectal polyps before they progress to cancer. According to current guidelines, people at average risk for this disease should be screened starting at age 50. Unfortunately, only 30 to 40 percent of people in this age group actually get screened, suggesting that we not only need to develop improved screening methods, but we also need to do a better job of encouraging people to take full advantage of available screening approaches. A number of screening methods are now in use and/or under clinical evaluation. One is the fecal occult blood test (FOBT), which is a relatively inexpensive and noninvasive test that detects hidden blood in stool. FOBT, recommended as an annual screening test, can reduce colorectal cancer deaths by up to 33 percent, according to study findings. Two other methods, flexible sigmoidoscopy and colonoscopy, are invasive procedures that allow a physician to visualize the inside of the lower part of the colon or the entire colon, respectively. Both of these methods are more expensive than FOBT, but they allow doctors to see such things as inflamed tissue, abnormal growths, and ulcers. Flexible sigmoidoscopy and colonoscopy are more effective than FOBT in detecting precancerous and cancerous growths; however, their invasiveness poses some risks to patients. Researchers are currently evaluating another screening method known as computed tomographic colonography or virtual colonoscopy. Virtual colonoscopy allows the physician to see the same images of the colon as with colonoscopy—without having to probe inside the body. Through an ongoing NCI-funded trial, researchers are trying to determine whether virtual colonoscopy is as effective as colonoscopy in detecting polyps and cancer. NCI is also supporting a large-scale clinical trial to determine whether screening with flexible sigmoidoscopy can reduce colorectal cancer deaths. Finally, scientists are testing a new, noninvasive method that looks specifically for mutations in DNA in stool samples that are indicative of colorectal cancer.
• We now know that certain inherited genetic mutations can increase a person's risk for colorectal cancer. About 75 percent of colorectal tumors, however, are sporadic and not known to have developed because of inherited genetic mutations. Scientists have been working to identify the genetic alterations that underlie these sporadic tumors. Over the last 15 years, studies have shown that mutations in key genes that control cell survival and death occur very early in the development of colorectal cancer.

Tomorrow

• A major challenge in colorectal cancer research is to characterize all of the key genetic changes associated with tumor initiation and progression. The Human Genome Project has established a firm foundation for this effort, and new projects focused on systematically exploring the entire spectrum of genomic changes involved in human cancer promise to bring us closer to meeting this challenge.
• Characterizing the molecular changes associated with colorectal cancer development and progression will allow us to identify both biological markers for this disease and relevant molecular targets for prevention and treatment.
• Developing new cell culture and animal model systems that reflect the full spectrum of this disease is an important part of research on colorectal cancer. These models will improve our ability to understand the biology of precancerous and cancerous colorectal lesions, learn about the interplay between environmental and genetic risk factors, and develop and test new targeted therapies to prevent and treat this disease.

Glossary Terms

A drug used to treat symptoms of cancer of the colon, breast, stomach, and pancreas. It is also used in a cream to treat certain skin conditions. 5-FU stops cells from making DNA and it may kill cancer cells. It is a type of antimetabolite. Also called 5-fluorouracil and fluorouracil.

Not normal. An abnormal lesion or growth may be cancer, premalignant (likely to become cancer), or benign (not cancer).

An animal with a disease either the same as or like a disease in humans. Animal models are used to study the development and progression of diseases and to test new treatments before they are given to humans. Animals with transplanted human cancers or other tissues are called xenograft models.

A drug used to treat several types of cancer, including certain types of colorectal, lung, breast, and kidney cancers and glioblastoma. It is also being studied in the treatment of other types of cancer. Avastin binds to vascular endothelial growth factor (VEGF) and may prevent the growth of new blood vessels that tumors need to grow. It is a type of antiangiogenesis agent and a type of monoclonal antibody. Also called bevacizumab.

A drug used to treat several types of cancer, including certain types of colorectal, lung, breast, and kidney cancers and glioblastoma. It is also being studied in the treatment of other types of cancer. Bevacizumab binds to vascular endothelial growth factor (VEGF) and may prevent the growth of new blood vessels that tumors need to grow. It is a type of antiangiogenesis agent and a type of monoclonal antibody. Also called Avastin.

A tissue with red blood cells, white blood cells, platelets, and other substances suspended in fluid called plasma. Blood takes oxygen and nutrients to the tissues, and carries away wastes.

A tube through which the blood circulates in the body. Blood vessels include a network of arteries, arterioles, capillaries, venules, and veins.

Having to do with the heart and blood vessels.

A drug that reduces pain. Celecoxib belongs to the family of drugs called nonsteroidal anti-inflammatory agents. It is being studied in the prevention of cancer.

The individual unit that makes up the tissues of the body. All living things are made up of one or more cells.

The growth of microorganisms such as bacteria and yeast, or human, plant, or animal cells in the laboratory. Cell cultures may be used to diagnose infections, to test new drugs, and in research.

The use of drugs, vitamins, or other agents to try to reduce the risk of, or delay the development or recurrence of, cancer.

Treatment that combines chemotherapy with radiation therapy. Also called chemoradiotherapy.

Treatment with drugs that kill cancer cells.

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. Also called clinical study.

The longest part of the large intestine, which is a tube-like organ connected to the small intestine at one end and the anus at the other. The colon removes water and some nutrients and electrolytes from partially digested food. The remaining material, solid waste called stool, moves through the colon to the rectum and leaves the body through the anus.

Examination of the inside of the colon using a colonoscope, inserted into the rectum. A colonoscope is a thin, tube-like instrument with a light and a lens for viewing. It may also have a tool to remove tissue to be checked under a microscope for signs of disease.

Cancer that develops in the colon (the longest part of the large intestine) and/or the rectum (the last several inches of the large intestine before the anus).

Treatment using more than one anticancer drug.

A method to examine the inside of the colon by taking a series of x-rays. A computer is used to make 2-D and 3-D pictures of the colon from these x-rays. The pictures can be saved, changed to better viewing angles, and reviewed after the procedure, even years later. Also called computed tomography colonography, CT colonography, CTC, and virtual colonoscopy.

An enzyme that speeds up the formation of substances that cause inflammation and pain. It may also cause tumor cells to grow. Some tumors have high levels of COX-2 and blocking its activity may reduce tumor growth. Also called cyclooxygenase-2 and prostaglandin-endoperoxide synthase 2.

To heal or restore health; a treatment to restore health.

An enzyme that speeds up the formation of substances that cause inflammation and pain. It may also cause tumor cells to grow. Some tumors have high levels of cyclooxygenase-2 and blocking its activity may reduce tumor growth. Also called COX-2 and prostaglandin-endoperoxide synthase 2.

The process of identifying a disease, such as cancer, from its signs and symptoms.

The length of time after treatment for a specific disease during which a patient survives with no sign of the disease. Disease-free survival may be used in a clinical study or trial to help measure how well a new treatment works. Also called DFS and disease-free survival time.

The molecules inside cells that carry genetic information and pass it from one generation to the next. Also called deoxyribonucleic acid.

Any substance, other than food, that is used to prevent, diagnose, treat or relieve symptoms of a disease or abnormal condition. Also refers to a substance that alters mood or body function, or that can be habit-forming or addictive, especially a narcotic.

A protein that speeds up chemical reactions in the body.

A test to check for blood in the stool. Small samples of stool are placed on special cards and sent to a doctor or laboratory for testing. Blood in the stool may be a sign of colorectal cancer. Also called FOBT.

A drug used to treat symptoms of cancer of the colon, breast, stomach, and pancreas. It is also used in a cream to treat certain skin conditions. Fluorouracil stops cells from making DNA and it may kill cancer cells. It is a type of antimetabolite. Also called 5-fluorouracil and 5-FU.

A test to check for blood in the stool. Small samples of stool are placed on special cards and sent to a doctor or laboratory for testing. Blood in the stool may be a sign of colorectal cancer. Also called fecal occult blood test.

An abbreviation for a chemotherapy combination used to treat colorectal cancer that is advanced or has come back. It is also being studied in the treatment of other types of cancer. It includes the drugs leucovorin calcium (folinic acid), fluorouracil, and oxaliplatin. FOLFOX-4, FOLFOX-6, and FOLFOX-7 are different in the doses of the three drugs and the ways they are given. Also called FOLFOX regimen.

Inherited; having to do with information that is passed from parents to offspring through genes in sperm and egg cells.

The complete genetic material of an organism.

The number of new cases of a disease diagnosed each year.

Redness, swelling, pain, and/or a feeling of heat in an area of the body. This is a protective reaction to injury, disease, or irritation of the tissues.

Transmitted through genes that have been passed from parents to their offspring (children).

A medical procedure that invades (enters) the body, usually by cutting or puncturing the skin or by inserting instruments into the body.

State of being separated from others. Isolation is sometimes used to prevent disease from spreading.

Surgery done with the aid of a laparoscope. A laparoscope is a thin, tube-like instrument with a light and a lens for viewing. It may also have a tool to remove tissue to be checked under a microscope for signs of disease. Also called laparoscopic-assisted resection.

An area of abnormal tissue. A lesion may be benign (not cancer) or malignant (cancer).

The active ingredient in a drug used to lessen the toxic effects of substances that block the action of folic acid, especially the anticancer drug methotrexate. Leucovorin is used to treat some types of anemia and is also used together with fluorouracil to treat colorectal cancer. It is also being studied in the treatment of other types of cancer and other conditions. Leucovorin is a form of folic acid. It is a type of chemoprotective agent and a type of chemosensitizing agent. Also called folinic acid.

An invasive malignant cancer confined entirely to the organ where the cancer began.

A diagnostic indication that disease may develop.

A statistics term. The middle value in a set of measurements.

A type of protein made in the laboratory that can locate and bind to substances in the body, including tumor cells. There are many kinds of monoclonal antibodies. Each monoclonal antibody is made to find one substance. Monoclonal antibodies are being used to treat some types of cancer and are being studied in the treatment of other types. They can be used alone or to carry drugs, toxins, or radioactive materials directly to a tumor.

Any change in the DNA of a cell. Mutations may be caused by mistakes during cell division, or they may be caused by exposure to DNA-damaging agents in the environment. Mutations can be harmful, beneficial, or have no effect. If they occur in cells that make eggs or sperm, they can be inherited; if mutations occur in other types of cells, they are not inherited. Certain mutations may lead to cancer or other diseases.

The National Cancer Institute, part of the National Institutes of Health of the United States Department of Health and Human Services, is the Federal Government's principal agency for cancer research. The National Cancer Institute conducts, coordinates, and funds cancer research, training, health information dissemination, and other programs with respect to the cause, diagnosis, prevention, and treatment of cancer. Access the National Cancer Institute Web site at http://www.cancer.gov. Also called NCI.

NCI, part of the National Institutes of Health of the United States Department of Health and Human Services, is the Federal Government's principal agency for cancer research. It conducts, coordinates, and funds cancer research, training, health information dissemination, and other programs with respect to the cause, diagnosis, prevention, and treatment of cancer. Access the NCI Web site at http://www.cancer.gov. Also called National Cancer Institute.

In medicine, it describes a procedure that does not require inserting an instrument through the skin or into a body opening. In cancer, it describes disease that has not spread outside the tissue in which it began.

Describes a condition that can be treated by surgery.

A drug used together with other drugs to treat colorectal cancer that is advanced or has come back. It is also being studied in the treatment of other types of cancer. Oxaliplatin attaches to DNA in cells and may kill cancer cells. It is a type of platinum compound. Also called Eloxatin.

Medical doctor.

A growth that protrudes from a mucous membrane.

After surgery.

A term used to describe a condition that may (or is likely to) become cancer. Also called premalignant.

Growths that may become cancer that protrude from a mucous membrane.

In medicine, action taken to decrease the chance of getting a disease or condition. For example, cancer prevention includes avoiding risk factors (such as smoking, obesity, lack of exercise, and radiation exposure) and increasing protective factors (such as getting regular physical activity, staying at a healthy weight, and having a healthy diet).

Initial treatment used to reduce a cancer. Primary treatment is followed by other treatments, such as chemotherapy, radiation therapy, and hormone therapy to get rid of cancer that remains. Also called first-line therapy, induction therapy, and primary therapy.

In medicine, the course of a disease, such as cancer, as it becomes worse or spreads in the body.

The use of high-energy radiation from x-rays, gamma rays, neutrons, protons, and other sources to kill cancer cells and shrink tumors. Radiation may come from a machine outside the body (external-beam radiation therapy), or it may come from radioactive material placed in the body near cancer cells (internal radiation therapy). Systemic radiation therapy uses a radioactive substance, such as a radiolabeled monoclonal antibody, that travels in the blood to tissues throughout the body. Also called irradiation and radiotherapy.

By or having to do with the rectum. The rectum is the last several inches of the large intestine closest to the anus.

The last several inches of the large intestine closest to the anus.

Cancer that has recurred (come back), usually after a period of time during which the cancer could not be detected. The cancer may come back to the same place as the original (primary) tumor or to another place in the body. Also called recurrent cancer.

A treatment plan that specifies the dosage, the schedule, and the duration of treatment.

A person who has studied science, especially one who is active in a particular field of investigation.

Checking for disease when there are no symptoms. Since screening may find diseases at an early stage, there may be a better chance of curing the disease. Examples of cancer screening tests are the mammogram (breast), colonoscopy (colon), Pap smear (cervix), and PSA blood level and digital rectal exam (prostate). Screening can also include checking for a person’s risk of developing an inherited disease by doing a genetic test.

Examination of the lower colon using a sigmoidoscope, inserted into the rectum. A sigmoidoscope is a thin, tube-like instrument with a light and a lens for viewing. It may also have a tool to remove tissue to be checked under a microscope for signs of disease. Also called proctosigmoidoscopy.

Tumor cells have spread to organs and lymph nodes near the colon/rectum. Also called Dukes C colorectal cancer.

The material in a bowel movement. Stool is made up of undigested food, bacteria, mucus, and cells from the lining of the intestines. Also called feces.

A procedure to remove or repair a part of the body or to find out whether disease is present. An operation.

A group or layer of cells that work together to perform a specific function.

An abnormal mass of tissue that results when cells divide more than they should or do not die when they should. Tumors may be benign (not cancer), or malignant (cancer). Also called neoplasm.

A process in which normal cells are changed so that they are able to form tumors. Substances that cause cancer can be tumor initiators.

The formation of a break on the skin or on the surface of an organ. An ulcer forms when the surface cells die and are cast off. Ulcers may be associated with cancer and other diseases.

A method to examine the inside of the colon by taking a series of x-rays. A computer is used to make 2-D and 3-D pictures of the colon from these x-rays. The pictures can be saved, changed to better viewing angles, and reviewed after the procedure, even years later. Also called computed tomographic colonography, computed tomography colonography, CT colonography, and CTC.