Colorectal Cancer Is (or Could Be) the Poster Child for Cancer Prevention

Posted by Mary Miller on February 14th, 2013

February is Cancer Prevention Month, and colorectal cancer (CRC) is a poster child, as one of the few cancers that can be literally seen and removed before it becomes cancer, or can be caught early enough in regular screening to be literally cured.

Ponder these facts, based on 20 years of experience and summarized by Linda Rabeneck, MD, MPH of Cancer Care Ontario at the recent “GI-ASCO” (Gastrointestinal Cancers Symposium of the American Society of Clinica Oncology):

 

stool test kit

  • Annual stool tests (fecal occult blood test, or FOBT) reduce deaths from colorectal cancer by 15 to 33 percent.
  • The newer FIT stool test (fecal immunochemical test) appears to be even better than the FOBT stool test at detecting CRC and early adenomas.
  • Flexible sigmoidoscopy (a scope exam of the lower colon) can reduce the cases of CRC by 21%, and deaths from CRC by 26%.
  • So-called ‘virtual colonoscopy’ (a special screening CT scan) finds up to 90% of people having adenomas or cancers that are at least 1 cm in diameter.

polypectomy-150x150Colonoscopy (examining the entire colon with an endoscope) is still considered by many to be the “gold standard” for detecting and removing precancerous lesions. Dr. Rabeneck noted, however, that colonoscopy continues to be much more effective in detecting lesions in the left (lower) colon than the upper (proximal) right colon, where hard-to-spot “flat” lesions are more likely to occur. (Evidence in the past few years shows that these flat “serrated sessile polyps” may develop differently and more quickly into CRC.)

Dr. Rabenick told the conference that updated national screening guidelines will be released in coming months; one likely change is removing barium enemas as a tool for CRC screening. Other research has raised the question about whether African Americans should start screening earlier (e.g. at age 50): Stay tuned.

 

PreventableColorectal_300x251-150x150

We can do better; much better

Despite the remarkable ability to detect and even prevent CRC, about 40% of Americans still don’t get the recommended screening. A recent study of 4000-plus Utah residents showed that 37% didn’t have recommended screening, even if they had a family history of colorectal cancer. The numbers of unscreened were much higher in rural areas.

 

Although it can be harder for some people (especially rural residents or those without full insurance coverage) to get a screening colonoscopy, they have choices:

  • A simple yearly stool test (high-sensitivity FOBT or FIT) that is done at home and mailed in;
  • Flexible sigmoidoscopy done every 5 years (most doctor’s offices do this test) along with stool tests every 3 years
  • A colonoscopy every 10 years or CT colonoscopy every 5 years.

People aged 76 to 85 without risk factors (such as a family history or certain number of polyps found over the years) usually don’t need routine screening (and those over age 85 can skip it because risks outweigh benefits).

Get more information and breaking CRC news

  • See a chart here that describes each screening option.
  • Stay tuned here for screening updates, and….

Rich Goldberg at ASCO-GI 2013

Learn more news with GI-ASCO Keynoter

Next Tuesday, Feb. 19, 2013, from 8 – 9:30 pm (EST), the ASCO-GI keynote speaker, internationally renowned CRC specialist (and member of our own Medical Advisory Board) Dr. Richard Goldberg will talk directly to and with you at our webinar “The Latest in Colorectal Cancer.” He’ll share a “Decade of Progress” plus also give us his take on the most interesting news to come out at ASCO-GI. You don’t get many chances to listen to a world-renowned expert: Register to join it live, or listen later to this and all archived webinars

Sources: “CRC Screening Tools–The Date and the Guidelines,” ASCO-GI Jan. 26 2013; “Screening for CRC: which Tool and How Often,” ASCO-GI Educational Summary  and “Rural vs. Urban Residence Affects Risk-Appropriate CRC Screening,” in press Clinical Gastroenterology and Hepatology.

FIT Beats All Other Screening for Effectiveness and Cost

Posted by Kate Murphy on December 2nd, 2010

In a computer simulation, FIT — fecal immunochemical testing — done every year saved more lives and cost the least of any colorectal cancer screening method, including colonoscopy.

The computer model looked at 100,000 average risk people and compared screening methods results for

  • number of colorectal cancer cases
  • number of colorectal cancer deaths
  • cost of screening and treating colorectal cancer for each screened person

Compared to not screening at all, annual FIT  could save 3 out of 4 deaths from colorectal cancer. For every 100,000 people between 50 and 75, nearly 3,500 people wouldn’t get colorectal cancer, and over 1,300 wouldn’t die.

Not only did FIT screening save the most lives, it was the most cost effective.  It saved about $70 (Canadian) in screening and cancer treatment expenses for each person screened, better than any other method. Read the rest of this entry »

Many Doctors Doing Colorectal Cancer Screening Wrong

Posted by Kate Murphy on May 11th, 2010

FOBT screening saves lives, but only when it is done right.

Three out of four primary care doctors did a fecal occult blood test once during an office visit, a method that is ineffective in finding cancer or preventing death from colorectal cancer. One out of four used the in-office test exclusively.

Less than half of doctors had a system in place to be sure that home tests were completed and returned.  Read the rest of this entry »

Screening Methods

Posted by Kate Murphy on February 29th, 2008

Comparing Screening Methods for Average Risk Patients

Tests that Detect Adenomatous Polyps and Cancer


Colonoscopy

  Every 10 years  

Most sensitive test for small and large polyps and cancers. Examines the entire colon, polyps can be removed and biopsied during the procedure.

 

Expensive, requires complete bowel cleansing. Normally uses sedation and requires someone to accompany patient, Rare instances of bowel perforation and bleeding. May not be covered by insurance.

Double-contrast barium enema

 

Every 5 years

 

Visualizes the entire colon, can detect most cancers, and the majority of large polyps. Helps patients who cannot complete a colonoscopy or where colonoscopy is not medically appropriate. Less expensive.

 

Requires complete bowel preparation. May be uncomfortable. An experienced radiologist is critical to quality exam. Colonoscopy is still required to biopsy lesions or removed polyps.

CT-colonography (virtual colonoscopy)

 

Every 5 years

 

Does not require sedation. No recovery time, patients can drive home or return to work. Finds cancer and large polyps at the same rate as colonoscopy. May find problems outside the colon as well.

 

Requires complete bowel preparation. Colonoscopy is required to biopsy and remove polyps. Technology and radiologist training are growing but not complete. May not detect non-polypoid colorectal neoplasms. May not be covered by insurance. False-positive problems identified outside the colon may require unnecessary follow-up tests.

Flexible sigmoidoscopy

 

Every 5 years

 

Can be done by primary care physician or trained nurse practitioner. Does not require sedation

 

Will miss polyps or cancers in the right colon beyond the reach of the scope. If polyps are found, colonoscopy and addition bowel preparation are required. Can be uncomfortable.

Tests that Primarily Detect Cancer


gFOBT: Guaiac-based stool test

 

Every year

  Inexpensive, is done privately at home, can be offered to many people through community programs, including those without primary care or insurance.  

Not very sensitive to polyps, will miss some cancers. Needs to be done correctly over three days. Requires diet and drug restrictions. Patients must handle stool. Has a high false positive rate that requires follow-up colonoscopy for about 1 in 3 tests.

FIT: Immunochemical stool test

  Every year   Has no diet or drug restrictions prior to the test. Limits blood detected to the colon and rectum . Is more sensitive than  guaiac-based tests for cancer. May be simpler for patients to do.

 

Will miss some cancers and most advanced polyps. More expensive than gFOBT. All positive tests require colonoscopy follow-up.

Stool DNA test   Not yet known  

Done at home privately. Not necessary to handle stool. Collection kit shipped directly to patient. No special diet prep required.

 

May not find all cancers or large polyps. Requires prompt, ice-pack shipment to special labs. Significantly more expensive than gFOBT or FIT. Colonoscopy follow-up necessary for positive test.