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Blood Test for Colon Cancer
 
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Blood Test for Colon Cancer



June 15, 2007 – A new blood test promises advance warning of colon cancer -- in plenty of time to find and remove precancerous growths.

The test detects either of two chemical markers abundant in colon cancers. The markers, dubbed colon-cancer-specific antigen-3 (CCSA-3) and CCSA-4, are also abundant in colon polyps that are well on their way to becoming colon cancers -- but appear to be rare in benign polyps and in other tissues.

Somehow, these markers find their way into the bloodstream, where they can easily be detected and measured. The leader of the team that found the markers and developed the test is Robert H. Getzenberg, PhD, professor of urology, oncology, pharmacology, and molecular sciences at Johns Hopkins University in Baltimore.

"Currently there are no blood tests for colon cancer. This would significantly change how people with colon cancer are detected," Getzenberg tells WebMD.

In preliminary studies, Getzenberg and colleagues tried out the test on 107 people undergoing routine screening colonoscopy, 28 people known to have colon cancer, and 125 people with various kinds of colon polyps or other cancers.

The test was 100% sensitive for colon cancer -- that is, it didn't miss a single patient. It was about 90% sensitive for identifying people who had either colon cancer or advanced adenomas (growths almost certain to become colon cancers).

The test was 82% to 91% specific, meaning that up to 18% of the time the test gave false-positive results in normal people and in people with benign polyps and other noncancerous growths.

"The goal here, the way we would use this, is to identify people who really need a colonoscopy," Getzenberg says.

Findings 'Exciting but Early'
Durado Brooks, MD, MPH, director of prostate and colorectal cancers for the American Cancer Society, doesn't agree that the test should be used in that way. Brooks, who was not involved in the Getzenberg study, notes that everyone who tests positive on the blood test would need a colonoscopy -- but what about those who test negative? Should they get a colonoscopy at some future time point, or a repeat blood test?

"At this point, we have to look at whether this has value as a standalone screening option," Brooks tells WebMD.

Brooks calls the new findings "very encouraging, but very early." He points out that the test still has to be validated in a large number of unselected people. Indeed, Getzenberg says such a study already is under way, with 500 people enrolled at several different institutions.

"In about two years we should have this thing out there," Getzenberg says.

Brooks hopes Getzenberg is right. However, he points to a possible problem with the test.

"The Hopkins data is a little concerning in that 16% of those with cancers other than colon cancer had a false-positive result," Brooks says. "That means that anyone who had a positive result on this test but a negative colonoscopy would have to embark on a tumor search. That would raise the price tag -- and the anxiety level -- for those who have false-positive test results."

Blood Tests for Other Cancers?
If all this sounds familiar, it is. Last April, Getzenberg's team reported a similar blood test for prostate cancer.

Getzenberg says his team is trying to concentrate on developing the prostate cancer and colon cancer tests. But he says the same technique he used to find the prostate- and colon-cancer markers should work for other cancers.

"I am almost positive this will work for a large number of cancer types -- maybe not all, but a large number," he says. "We will help other people do this. It is an approach we have found to be very productive in finding cancer-specific markers that people have been searching for for a while."

SOURCES: Getzenberg, R.H. Cancer Research, June 15, 2007, manuscriipt received ahead of publication. Robert H. Getzenberg, PhD, director of urology research, Brady Urological Institute; professor of urology, oncology, pharmacology, and molecular sciences, Johns Hopkins University, Baltimore. Durado Brooks, MD, MPH, director, prostate and colorectal cancers, American Cancer Society, Atlanta.

ADDITIONAL INFORMATION
March 6, 2008, 5:08PM
Shares Soar for Colon Cancer Test Maker
© 2008 The Associated Press
MARLBOROUGH, Mass. — Shares of Exact Sciences Corp., maker of a colon cancer screening test that's noninvasive, soared Thursday after the American Cancer Society recommended that the test should become one of the tools used to screen for the often-fatal form of cancer.

Shares of the small, Marlborough-based firm rose nearly 45 percent to $3.03 on Thursday, after climbing as high as $4.25 earlier.

Exact Sciences' test involves collecting a stool sample at home and shipping it to a lab for testing. The lab analyzes DNA from the sample to see whether mutations are present that could indicate colon cancer.

After markets closed Wednesday, the American Cancer Society recommended the test, along with another procedure known as a virtual colonoscopy.

The recommendations bring to six the number of screening tests suggested for spotting signs of colon cancer, the nation's second leading cancer killer. It will kill about 50,000 people in the United States this year, the Cancer Society estimates. Screenings are designed to save lives by finding growths before they turn cancerous.

But only 30 percent of people recommended to get screenings do, according to the Cancer Society. Many people balk at getting colonoscopies because the test is expensive and can be unpleasant.

Traditional colonoscopies, long considered the gold standard test, are recommended every 10 years, starting at age 50. A doctor snakes a long, thin tube equipped with a small video camera through the large intestine to view the lining. The doctors also can use the device to cut away a tissue sample or even remove a polyp.

A virtual colonoscopy is a sort of super X-ray of the colon and rectum. Air is pumped into the colon to stretch it, and then a special CT scan is done. It is not invasive, but if a polyp is found, doctors will have to perform an optical colonoscopy in order to take a biopsy

NEW INFORMAION
Flavonoids Found to Help Colorectal Health
By Greg Arnold, DC, CSCS, June 18, 2008, abstracted from “Dietary Flavonoids and Colorectal Adenoma Recurrence in the Polyp Prevention Trial” in the June 2008 issue of Cancer Epidemiology Biomarkers and Prevention

Colorectal cancer is the second leading cause of death from cancer (behind lung cancer) in the United States. It claims more than 55,000 Americans each year and poses a risk for nearly 1 in 4 Americans (80 to 90 million) because of age or other factors. It affects both men and women equally1.

Fortunately, a number of ways are available to help colon health, including calcium2, conjugated linoleic acid3, vitamin B64, green tea5, fiber6, olive oil7 apples8 and omega-3 fats9. Now a new study10 has found that flavonols, a group of over 5,000 compounds11 contained in almonds12 as well as fruits and vegetables13 that benefit colon health14, pancreas health15, and breast cell health16, may also help colorectal health.

In the study, researchers analyzed data on over 1,900 patients who participated in the Polyp Prevention Trail (PPT). This was a four-year randomized, multi-center, nutritional intervention trial that evaluated whether following a high-fiber diet (18 grams of fiber per 1,000 calories), high-fruit and high-vegetable (5 servings per day), and low-fat (no more than 20% of total calories) diet is effective in inhibiting colorectal adenoma recurrence17. The researchers found that total flavonoid intake did not significantly reduce the risk of having a recurrence of colorectal adenomas. However, there was a 36% reduced risk of having an advanced recurrence of adenomas in the highest flavonoid intake group (more than 106 mg per day) compared to the lowest intake (less than 51 mg per day).

When looking at specific flavonoids, they found that flavonols (more than 17.3 mg per day compared to less than 8.12 mg per day) and isoflavonoids (more than 0.133 mg per day compared to less than .045 mg per day) produced a 76% and 54% reduced risk of any recurrence, respectively. Flavonols are found mostly in apples, beans, broccoli, and onions while isoflavonoids are found mostly in bean and soy products.

For the researchers, “our data suggest that a flavonol-rich diet may decrease the risk of advanced adenoma recurrence.”

Greg Arnold is a Chiropractic Physician practicing in Danville, CA. You can contact Dr. Arnold directly by emailing him at mailto:PitchingDoc@msn.com or visiting his web site at
http://www.CompleteChiropracticHealthcare.com


Reference:

1 “Colorectal Cancer Fact Sheet” posted on the Foundation for Digestive Health and Nutrition Website
http://www.fdhn.org/html/education/colorectal/facts.html


2 Meunier, P. J. (1999). "Calcium, vitamin D and vitamin K in the prevention of fractures due to osteoporosis." Osteoporos Int 9 Suppl 2: S48-52

3 Larsson SC. High-fat dairy food and conjugated linoleic acid intakes in relation to colorectal cancer incidence in the Swedish Mammography Cohort. Am J Clin Nutr 2005 82: 894-900

4 Theodoratou E. Dietary Vitamin B6 Intake and the Risk of Colorectal Cancer. Cancer Epidemiol Biomarkers Prev 2008 17: 171-182 doi: 10.1158/1055-9965.EPI-07-0621

5 Yong G. Prospective Cohort Study of Green Tea Consumption and Colorectal Cancer Risk in Women. Cancer Epidemiol Biomarkers Prev 2007 16: 1219-1223 doi: 10.1158/1055-9965.EPI-07-0097

6 Jacobs ET. Fiber, sex, and colorectal adenoma: results of a pooled analysis. Am. J. Clinical Nutrition, Feb 2006; 83: 343 – 349

7 Gill, C. I., A. Boyd, et al. (2005). "Potential anti-cancer effects of virgin olive oil phenols on colorectal carcinogenesis models in vitro." Int J Cancer 117(1): 1-7

8 Waldecker M. Histone-deacetylase inhibition and butyrate formation: Fecal slurry incubations with apple pectin and apple juice extracts. Nutrition 2008; 24(4): 366-374

9 Hall MN. A 22-year Prospective Study of Fish, n-3 Fatty Acid Intake, and Colorectal Cancer Risk in Men. Cancer Epidemiol Biomarkers Prev 2008 17: 1136-1143 doi: 10.1158/1055-9965.EPI-07-2803

10 Bobe G. Dietary Flavonoids and Colorectal Adenoma Recurrence in the Polyp Prevention Trial. Cancer Epidemiol Biomarkers Prev 2008 17: 1344-1353 doi: 10.1158/1055-9965.EPI-07-0747

11 Aherne SA, O'Brien NM. Dietary flavonols: chemistry, food content, and metabolism. Nutrition 2002;18:75–81

12 Milbury, P; Chen, CY; Dolnikowski, G; Blumberg, J; Determination of Flavonoids and Phenolics and Their Distribution in Almonds. J. Agric. Food Chem 2006; 54:5027-5033

13 Erdman JW Jr, Balentine D, Arab L, et al. Flavonoids and heart health: proceedings of the ILSI North America Flavonoids Workshop, May 31–June 1, 2005, Washington, DC. J Nutr (2007) 137:718S–37S

14 Rossi M. Flavonoids and Colorectal Cancer in Italy. Cancer Epidemiol Biomarkers Prev 2006 15: 1555-1558

15 Bobe G. Flavonoid Intake and Risk of Pancreatic Cancer in Male Smokers (Finland). Cancer Epidemiol Biomarkers Prev 2008 17: 553-562 doi: 10.1158/1055-9965.EPI-07-2523

16 Dietary flavonoid intake and Breast Cancer risk among women in the long island Breast Cancer study project”. Abstract #4014 at the 97th Annual Meeting of the American Association in Cancer Research.

17 Lanza E, Schatzkin A, Ballard-Barbash R, et al. The polyp prevention trial II: dietary intervention program and participant baseline dietary characteristics. Cancer Epidemiol Biomarkers Prev 1996;5:385–92

NEW POSTING
New fecal test for colon cancer
Colon Cancer
RanplexCRC is a diagnostic test that can detect 28 polymorphisms associated with colorectal cancer in a single stool sample. It does not require a hospital visit or dietary restrictions, while having greater sensitivity than the currently used Faecal Occult Blood (FOB) screening test. RanplexCRC may more accurately profile patients and reduce the number of patients for colonoscopy, saving time and resources and reducing patient discomfort.

Most sporadic colorectal cancers follow a well recognised progression from normal cells through adenoma (abnormal glandular growths) to cancer, driven by mutations in a small number of genes. RanplexCRC can simultaneously detect 28 mutations from four key genes in cancer or pre-cancer cells shed into the bowel. Selected mutations present in APC, KRAS, BRAF and Tp53, along with wild-type control sequences, are represented on 2 biochips detected using Randox's Biochip Array Analysers.

The Randox family of Biochip Array analysers are immunoassay testing platforms that work by combining panels of related tests on a single biochip. The chemiluminescent endpoint is detected by a CCD-camera and quantified by a custom image-processing software. Evidence, a fully automated analyser for high-throughput laboratories, and the Evidence Investigator, a semi-automated analyser for low-throughput laboratories and research purposes, are both available from Randox.

Bowel (colorectal) cancer is the second largest cause of cancer mortality in the western world, but up to 90% curable if detected early. Unfortunately, most patients present with advanced disease, reducing their long term survival. National Screening programmes are being introduced throughout Europe, to reduce CRC mortality, using the FOB test. This cheap and non-invasive test detects blood in stool samples, which may be an indication of a tumour. Patients with a positive FOB test are then referred for colonoscopy. The FOB test, however, suffers from poor sensitivity, as not all tumours bleed (false negative test) and not all stool-blood is derived from tumours (false positive test). Many patients (up to 50%) may therefore be sent for colonoscopies unnecessarily. Colonoscopies are invasive, involve dietary restrictions and require the presence of a surgeon, so an intermediate test would benefit both the patient and the healthcare system. RanplexCRC provides the answer, filtering out false positives.

About Randox

Randox is an international diagnostics company, headquartered in the UK. Randox develop, manufacture and market clinical diagnostic products worldwide. Core products are: Biochip Array Technology; clinical chemistry analysers and reagents; quality controls and EQA; environmental diagnostics; recombinant proteins and antibodies.












 

 
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