Scientists have found that Neurontin® (gabapentin) does not reduce neuropathy symptoms from oxaliplatin treatment. 

Because the drug has been helpful in other causes of peripheral neuropathy, researchers in the North Central Cancer Treatment Group (NCCTG) and at the Mayo Clinic randomly assigned patients who had significant pain from neuropathy to receive either gabapentin or a placebo.  After six weeks of treatment, patients crossed over to either active drug or placebo so all patients eventually were treated with gabapentin.

The trial was double-blinded — neither patient nor doctor knew whether or not the drug or the placebo was being used.

Peripheral neuropathy — tingling, numbness, and pain in the hands and feet — is a side effect of treatment with Eloxatin (oxaliplatin).  Oxaliplatin, combined with 5FU and leucovorin or FOLFOX, is a standard treatment for colorectal cancer.

The research team concluded:

This trial failed to demonstrate any benefit to using gabapentin to treat symptoms caused by chemotherapy-induced peripheral neuropathy.

SOURCE: Rao et al, Cancer, Volume 110, Issue 9, published online September 12, 2007.

WHAT THIS MEANS FOR PATIENTS

Although Neurontin is sometimes prescribed off-label to treat pain and numbness caused by FOLFOX chemotherapy, it is unlikely to be more helpful that a sugar pill.

Clinical Trial Information

Researchers at Roswell Park Cancer Center are testing Vitamin D3 (cholecalciferol) in combination with calcium carbonate to prevent colon cancer from coming back after treatment is finished.  Patients to be enrolled will have had surgery and been without signs of cancer for at least one year.

Scientists will be studying changes in the lining of the rectum along with blood and urine levels of markers of vitamin D, calcium, and parathyroid functioning.  In addition, they’ll be assessing the safety of high-dose Vitamin D3 given over a two year period.

Patients in the study will receive either:

• Oral high dose Vitamin D3 daily along with oral calcium supplements twice each day.
• Oral low dose Vitamin D3 along with calcium twice daily.

Biopsies of the lining of rectum will be taken at the beginning of the study and after 6 months of the supplements during either sigmoidoscopy or colonoscopy.

Treatment will last for two years unless cancer recurs or there are unacceptable side effects.

Contact the trial at Roswell Park

• Marwan Fakih, MD, Principal investigator
  
• Ph: 716-845-3362; 800-685-6825
• Email: marwan.fakih@roswellpark.org

INFORMATION from 2007 Annual Scientific Meeting of the American College of Gastroenterology

Obesity heads the list of risk factors for developing colorectal cancer in women.  It is more important than smoking according to information reported at the Annual Scientific Meeting of the American College of Gastroenterology in Philadelphia this month.

Headed by Joseph C. Anderson MD, researchers at Stony Brook University in New York and the University of Connecticut looked at data from nearly 1,300 women who had colonoscopy.  They focused on risk factors that included

• Obesity:  Body Mass Index (BMI) over 30
• Smoking:  heavy, low, and no exposure. 
• Family history of colorectal cancer.
• Age

Although smoking contributed significantly to women who had advanced precancerous polyps or cancer, high BMI was found more often.  Twenty percent of women with serious colorectal neoplasia were obese, fourteen percent were smokers.

Dr. Anderson said,

Given the increasing number of obese patients in the U.S., identifying them as high risk may have important screening implications. While obesity is positively associated with an increased risk of colorectal cancer, patients who lower their BMI could potentially reduce their risk of developing the disease in the future.

SOURCE:  American College of Gastroenterology Press Release, October 15, 2007, Philadelphia.

The rate of both men and women who are diagnosed annually with colon or rectal cancer is falling and so are deaths from the disease.

Death rates for colorectal cancer declined sharply — nearly 5 percent for men and 4.5 percent for women each year between 2002 and 2004.

Between 1998 and 2004 the rate of people diagnosed with colon or rectal cancer (incidence)  fell an average of 2.6 percent each year for men and 2.2 percent for women. 

For all cancers, the annual percentage rate of those diagnosed fell 2.1 percent each year between 2002 and 2004.

In those years death rates from all cancers declined  2.1 percent — 2.5 percent for men and 1.8 percent for women.

The information comes from the annual Report to the nation on the status of cancer diagnosis and deaths developed collaboratively by the American Cancer Society, the Centers for Disease Control, the National Cancer Institute, and the North American Association of Central Cancer Registries.

In discussing reasons for the reduction in colorectal cancer rates, the authors conclude,

After steadily decreasing for many years, the decline in colorectal cancer death rates has accelerated. The concurrent declines in colorectal cancer mortality and incidence are likely associated with preventing colorectal cancer through screening and removal of precancerous polyps, improving cancer outcomes by earlier stage diagnosis, reducing exposure to risk factors, and improving cancer treatment.

However, as other reports have consistently shown, less than half of Americans have been screened for colorectal cancer  Among the white population in the United States,  the Report to the Nation found that 44 percent of men and 39.5 percent of women had a colorectal scope exam in the past five years.  Women were much more likely to have had a pap smear (86.4 percent) or a mammogram (76.4 percent).

 The Report looked at health care for non-Hispanic whites and found that more than 10 percent had no health coverage.  More than 16 percent of people aged 16 to 64 were without care.

Previous studies found that after Medicare began paying for colonoscopy screening in 1998, the rate of colonoscopy screening increased nearly seven-fold.

The Cover Your Butt campaign is working to increase access to colorectal cancer screening for all Americans.

SOURCE: Espey et al, Cancer, Published online, October 15, 2007.

Similar numbers of advanced polyps or cancers were detected in a large screening study that compared computed tomographic colonography (so-called virtual colonoscopy) to traditional optical colonoscopy.  CT-colonography uncovered 123 advanced neoplasms including 14 cancers, optical colonoscopy found 121, with 4 cancers. 

CT-colonography uses a series of  x-rays to detect colorectal polyps and cancers while colonoscopy looks for them directly using a thin, fiber-optic scope inserted into the rectum and colon. 

Participants in the non-randomized study chose either to have CT-colonography  or optical colonoscopy as their initial screening test.  If a polyp larger than 6 millimeters was was found during CT-colonography, the individual had a colonoscopy to remove the polyp on the same day. If a polyp of any size was found during optical colonoscopy, it was removed during the procedure.

About 8 percent of patients were referred from CT-colonography to optical colonoscopy for polyp removal. 

Advanced adenomas — those at least 1 centimeter in size or with high risk changes in pathology – have the greatest risk to become colon or rectal cancer if not removed. 

Because all polyps — large and small — were removed in the group who chose optical colonoscopy as the primary procedure, there were almost five times as many polyps removed:  2434 compared to 561.  There were also seven colon perforations, while there were no perforations in the group had colonoscopy after an initial CT-colonography.

Both procedures required liquid diets and laxatives to cleanse the colon completely.

For this study, the research team convinced insurers to pay for the CT-colonography although it is still considered to be experimental.

David Kim, MD, and his colleagues at the University of Wisconsin in Madison concluded,

Primary CTC and OC screening strategies resulted in similar detection rates for advanced neoplasia, although the numbers of polypectomies and complications were considerably smaller in the CTC group. These findings support the use of CTC as a primary screening test before therapeutic OC.

Currently CT-colonoscopy is not included in recommendations for colorectal cancer screening.  However, those guidelines are being revised and may include the procedure in the future. 

All men and women over the age of 50 should be screened for pre-cancerous polyps prevent colorectal cancer.

SOURCE:  Kim et al, New England Journal of Medicine, Volume 357, Number 14, pages 1402-1412, October 4, 2007.

The Associated Press released an article about the study on October 3, 2007.