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COLOGUARD - An Easier Test for Colorectal Cancer Screening

April 9, 2018

COLOGUARD-An Easier Test

For Colorectal Cancer Screening

Intro:

  • The CDC estimates that 23 million people ages 50-75 are skipping colonoscopies, which is the gold standard for colorectal cancer screening.
  • 30% of screen eligible individuals are not getting colonoscopies or any other CRC screening.
  • Colon cancer is the 2nd leading cause of cancer deaths in the U.S., and claims the lives of 50,000 American annually.
  • This cancer is very treatable if detected early, with screening people diagnosed at stage I have a 93-95% survival rate, while those diagnosed at stage IV have only a 12% survival rate.

What is COLOGUARD:

  • It is an at home, stool-based test for colorectal cancer that approved by the FDA in 2014.
  • It is intended for the qualitative detection of colorectal neoplasia associated DNA markers and for the presence of occult hemoglobin in human stool
  • Works by detecting DNA changes characteristic of cancerous lesions or polyps, which are present in the cells lining the colon.
  • Just one stool sample is needed.
  • No dietary restrictions required.
  • Also considered in equal standing to other current colorectal screening by the American Cancer Society and the USPSTF.
  • Covered by Medicare Insurance and Anthem Blue Cross of CA PPO.

Indications:

  • Cologuard is recommended every three years for 50 to 85 y/o at average risk of colon cancer, no need for colonoscopy unless the Cologuard are abnormal.
  • Cologuard is not a replacement for diagnostic colonoscopy or surveillance colonoscopy in high risk individuals.

Contraindications:

  • Patients younger than 50 y/o.
  • Patients with history of colorectal cancer, adenomas, or other related cancers.
  • Patients who have had a positive result from another colorectal cancer screening method within the past 6months.
  • Patients who have been diagnosed with a condition that is associated with high risk for colorectal cancer. These include but not limited to:
    • IBD
    • Chronic ulcerative colitis
    • Crohn’s disease
    • Familial adenomatous polyposis
    • Family history of colorectal cancer

 

Warnings and Precautions:

  • This is relative new screening method, its performance has only been established in cross sectional study (ie. A single point in time), the benefits and risks with repeated testing over an established period of time has not been studied.
  • We do not know yet how Cologuard compares to colonoscopy as a primary screening tool.

The Data:

  • Primarily from a prospective, multi-centered, pivotal trial, called the DeeP-C Study. A total of 12,776 patients were enrolled from 90 sites, including both colonoscopy centers and primary care sites.
  • Cologuard demonstrated 92.3% CRC sensitivity and 86.6% specificity, colonoscopy has a 95% sensitivity.
  • Cologuard is as accurate at the colonoscopy in detecting 94% of stage I and II colon cancers, and since the test is done more frequently than colonoscopy, it could have even higher overall detection rates.
  • Compared to fecal immunochemical test (FIT), Cologuard picked up cancers 92% of the time, compared to FIT at 74%.
  • Cologuard has a higher rate of false positives than FIT cards, 10%, to 5% for FIT test. However, over time since people undergo Cologuard every three years instead of every year, Cologuard has fewer positives than FIT.
  • Of note, if Cologuard is negative, there is only a 0.06% chance there is cancer.

The Advantages:

  • Cologuard detects lesions on both the right and left side of colon with equal sensitivity, whereas FIT and colonoscopy detect mostly lesion on the left side. Moreover, some studies have shown an increase of tumors on the right side, making new screening methods necessary.
  • Cologuard is operator independent.
  • Cologuard is safe.
  • Cologuard more convenient.
  • No need for sedation in Cologuard.