New Colorectal Cancer Test Offers Hope for Early Detection According to a report in the November issue of the journal Gastroenterology , early detection of colorectal cancer and precancerous tumors may be possible with a new screening test that involves looking for abnormal DNA in stool samples. When detected early, colorectal cancer is a highly curable disease. Colorectal cancer begins with the development of an adenomatous polyp, which is a small benign tumor that grows in the colon. These polyps take 10 to 15 years to transform into cancer. Since this development phase is so long, screening and early detection can play a crucial role in the prevention of colorectal cancer, as detection and removal of the polyps can prevent the development of the disease. As the polyp develops, there are changes in the tumor’s DNA. By examining tumors that have been removed from patients, researchers have identified some of these altered DNA molecules. The tumors shed cells into the intestine, which makes it possible to detect the abnormal DNA cells in stool samples. In a recent study at the Mayo Clinic, researchers examined the stool samples of three different groups: 22 people who had been diagnosed with colorectal cancer, 11 people who had polyps, and 28 people without any colorectal tumors. They found abnormal DNA in 91% of the stool samples from cancer patients and 73% of the stool samples from the patients with polyps. None of the stool samples from tumor-free people had abnormal DNA. The results of this study show that DNA stool testing has the potential to become an efficient screening test for colorectal cancer. This could be an accurate and non-invasive test that people might be more willing to undergo than other more intrusive and uncomfortable tests. A 3-year clinical trial funded by the National Cancer Institute is scheduled to begin in January in order to further evaluate this procedure. In the meantime, it is still important for people to utilize the existing methods of screening for colorectal cancer, which include the fecal occult blood test (FOBT), sigmoidoscopy, colonoscopy and the double-contrast barium enema. People concerned with screening for this disease can consult with their physicians for more information. Future clinical trials will help to establish the feasibility of using DNA stool testing as a standard screening procedure. People who are at a high-risk for developing colorectal cancer may wish to speak with their physicians about the risks and benefits of participating in a clinical trial in which DNA stool testing and other promising new screening techniques are being evaluated. Two sources of information about ongoing clinical trials include clinical trials listing services provided by the National Cancer Institute ( cancer.gov ) and eCancerTrials.com . eCancerTrials.com also performs personalized clinical trial searches on behalf of patients.
Selenium May Reduce Risk of Developing Lung, Colorectal, and Prostate Cancers The essential dietary nutrient, selenium, may help reduce the risk of developing cancers of the lung, colon, rectum, and prostate, as well as reduce the number of deaths in persons who have certain types of cancer, according to preliminary research findings. It is believed that cancer is caused by a number of factors, making prevention of the disease a challenge. Few cases of cancer have a causative association as clear as the one between smoking and lung cancer. However, ongoing research continues to elucidate characteristics or exposures that may increase the chance of developing different types of cancers ( risk factors ) as well as characteristics or exposures that may reduce the chance of developing those cancers ( protective factors ). Recently, much attention has been given to the potential protective effects of various dietary supplements and nutrients, including selenium. Selenium is a nutrient that is essential to the human body. A component of a number of the body’s enzymes, selenium is found predominantly in foods but also in water and air. Several scientific reports have shown an increased risk of developing certain cancers when the diet does not contain enough selenium. Similarly, some clinical studies have shown that selenium supplements in the diet may reduce the risk of developing some cancers. The side effects of most forms of selenium are low; however, certain forms (such as selenious acid) can be fatal if ingested. Excessive exposure to selenium, often characterized by a garlic odor on the breath, can result in chronic selenium poisoning. Further investigation of the potential protective effect of selenium from some types of cancer is ongoing. Researchers from several centers in the United States conducted a study to determine whether the use of selenium supplements would result in a reduced risk of developing cancer or a recurrence (return) of cancer in 1312 persons who had a history of basal cell or squamous cell cancer of the skin. The researchers assigned the patients to receive either 200 micrograms of selenium per day or a placebo. The findings showed that the selenium did not have any impact on whether the patients developed the skin cancer again. However, the selenium was associated with fewer cancer-related deaths. Of the group receiving placebo, 57 persons died of cancer; of the group receiving selenium, 29 persons died of cancer. Of the cancers that were diagnosed, 119 were in the placebo group and 77 were in the selenium group. Cancers that were shown to be reduced in the selenium group included lung, colorectal, and prostate cancers. Because of these favorable results showing reductions in the incidence of lung, colorectal, and prostate cancers and the reduction in deaths from cancer, this study was stopped early. The researchers concluded that the protective effects of selenium shown here appear promising; however, further studies are needed to confirm these findings. ( Journal of the American Medical Society , Vol 276, No 24, pp 1957-1963)
Intensive Chemotherapy and Radiation Therapy Combo May Improve Outcomes for Persons with Cancer of the Anus
Intensive Chemotherapy and Radiation Therapy Combo May Improve Outcomes for Persons with Cancer of the Anus Persons who have cancers of the anus that have spread to the nearby lymph nodes or are large in size may require more aggressive therapy than individuals with smaller cancers. Now, researchers say that chemotherapy with fluorouracil and cisplatin, followed by a combination of radiation therapy and chemotherapy with fluorouracil and mitomycin, may help preserve bowel function and improve survival for persons with this type of disease. Cancer of the anus , the opening at the end of the rectum, is an uncommon cancer. Depending on the stage of disease (extent of disease at diagnosis) and other factors, cancer of the anus may be treated with surgery, chemotherapy, and/or radiation therapy. Persons who have surgery for anal cancer sometimes need a colostomy , an opening created from the skin to the bowel to help dispose of waste; however, a colostomy is usually temporary. Persons who have anal cancer that can be operated upon are often treated with surgery followed by a combination of radiation therapy and chemotherapy with fluorouracil and mitomycin. Seventy percent of these individuals are cured and maintain bowel functioning. However, persons with anal cancers that are large in size or have spread to the lymph nodes, do not respond as well to the standard therapies and need more aggressive treatment. Researchers from the Cancer and Acute Leukemia Group B conducted a study with the hope of improving survival rates and preserving bowel function for persons with cancer of the anal canal that were large in size or had spread to the lymph nodes. Forty-five patients first received chemotherapy with fluorouracil and cisplatin. They then received a combination of radiation therapy and chemotherapy with fluorouracil and mitomycin. Thirty-six patients had a complete response to the therapy. After an average of 21 months, 78% of the patients were alive and 67% were free from any signs and symptoms of cancer. Fifty-six percent of those who were alive were without a colostomy. The researchers concluded that this more aggressive combination of chemotherapy and radiation therapy appears to result in better survival and better preservation of bowel functioning than the standard regimens for persons with more advanced anal cancer. Persons with this type of disease may wish to talk with their doctor about the risks and benefits of receiving intensive chemotherapy with radiation therapy or of participating in a clinical trial in which other promising new therapies are being studied. Two sources of information on ongoing clinical trials that can be discussed with a doctor include a comprehensive, easy-to-use service provided by the National Cancer Institute ( cancer.gov ) and the Clinical Trials section and service offered by Cancer Consultants.com ( www.411cancer.com ). ( Proceedings of the American Society of Clinical Oncology Thirty-Fifth Annual Meeting , Vol 18, Abstract 909, pp 237a, 1999)
Surgical Salvage Therapy is Effective Treatment for Patients with Rectal Cancer that Relapse Locally after Initial Sphincter-Conserving Treatment
Surgical Salvage Therapy is Effective Treatment for Patients with Rectal Cancer that Relapse Locally after Initial Sphincter-Conserving Treatment The standard of care for most patients with anal cancer is now initial treatment with radiation or chemoradiotherapy, with the aim of preserving the anus and allowing sphincter function. With this approach, approximately 60-90% of patients can expect to have the cancer eradicated. The majority of these patients will be cured and continue to have a functioning anus. A portion of patients undergoing this initial treatment will, however, have recurrence of the cancer. If the cancer recurs locally, without the development of distant metastases, the patient then needs to undergo radical surgery in order to “salvage” a second chance of being cured. There has been a paucity of data on how well patients do after this kind of salvage surgery following initial sphincter-preserving treatment. In a recent publication, doctors from the Geneva University Hospital, Switzerland, analyzed their 20-year experience in treating anal cancer with sphincter-preserving techniques. Approximately 20% of the patients failed locally. Two thirds of the patients failing locally had no evidence of metastases and so were still potentially curable. The surgical salvage treatment consisted mainly of abdominoperineal resections in which the tumor and anus are surgically removed in one piece. Of this group of patients, approximately half continue to enjoy freedom from recurrence at 5 years and, in all likelihood, are cured. This study reaffirms the validity of sphincter-preservation as the initial treatment for anal cancer. A good proportion of patients who fail this initial treatment are still salvageable by surgery. Future efforts will be directed at further improving the cure rate with the initial treatment, as well as strategies to detect recurrence at an early stage when surgical salvage is still possible. ( Cancer , Vol 86, No 3, pp 405-409, 1999)
Treatment of Anal Cancer: Protective Drug, Called Amifostine, Reduces the Side Effects of Chemotherapy and Radiation Therapy
Treatment of Anal Cancer: Protective Drug, Called Amifostine, Reduces the Side Effects of Chemotherapy and Radiation Therapy The side effects of chemotherapy and radiation therapy as treatment for anal cancer may be reduced with the use of a drug called amifostine, according to new research findings by German doctors. Cancer of the anus, the opening at the end of the rectum, is an uncommon cancer. Depending on the stage of disease (extent of disease at the time of diagnosis) and other factors, anal cancer may be treated with surgery, chemotherapy, and/or radiation therapy. Radiation and chemotherapy are often administered after surgery (called adjuvant treatment) to help control the cancer, but these treatments often cause side effects. Over the past 50 years, many drugs, called radiation protectors, have been tested in the laboratory for the prevention of damage to healthy cells and tissues from radiation therapy. For such drugs to work effectively, they must protect the healthy cells, but not the cancerous cells. Amifostine is the only agent of this category to be approved by the US Food and Drug Administration for use in patients receiving radiation therapy for cancer of the head and neck. This drug has also been shown to reduce the side effects from chemotherapy in patients with cancer of the ovary. Doctors in Germany studied the protective effects of amifostine in patients receiving both chemotherapy and radiation therapy for cancer of the anus. In this study, 30 patients with advanced cancer of the anus underwent surgery, then 5 weeks of radiation therapy and chemotherapy. Half of the patients also received amifostine in weeks 1 and 5 of treatment, while the other half received no amifostine. The results show that amifostine was associated with a reduction in side effects of the skin, bowel, and blood. The side effects associated with amifostine use included low blood pressure and nausea. The researchers concluded that amifostine may be a useful agent in preventing the side effects caused by radiation therapy and chemotherapy in patients with cancer of the anus. Further studies of the protective effects of amifostine against radiation therapy and/or chemotherapy for other types of cancer are needed. ( Presented at the 41st Annual Meeting of the American Society of Therapeutic Radiology and Oncology , October 31, 1999, San Antonio, Texas)