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Screening for Colon Cancer Relapse
I am a colon cancer survivor. Because the possibility of a relapse is unimaginable to me, screening for possible colon cancer relapse is essential. The issue is what type of test, and how often do I screen?
To be honest, once I listed all of the tests below, I became a bit overwhelmed… I’m going to have to study these tests to determine which apply to my situation and which don’t.
Thanks,
- Bernie Davis
- Colon Cancer Survivor
What tests are used to screen for colon cancer relapse?
Tests to screen for colon cancer relapse include:
CEA blood tests, which monitor a tumor marker, and imaging scans like CT or PET scans to detect metastases or local recurrence. A colonoscopy is also used to check for local recurrence or new polyps, and some genetic tests, like the Oncotype DX Colon Recurrence Score, can be used to assess a patient’s risk of recurrence based on the tumor’s biology.
Blood tests-
- CEA (carcinoembryonic antigen) blood test: Measures the level of a protein that may indicate the presence of cancer. CEA levels are often monitored every 3 to 6 months for the first few years after treatment.
- ctDNA (circulating tumor DNA) tests: Look for small traces of tumor DNA in the blood to detect recurrence, such as the Signatera test.
Imaging tests-
- CT scans: Provide detailed cross-sectional images of the chest, abdomen, and pelvis to detect if the cancer has spread to other organs or if a local recurrence has occurred.
- MRI or PET scans: May be used for more detailed imaging in specific cases to detect recurrence or metastases.
Endoscopic procedures-
- Colonoscopy: A doctor uses a flexible tube with a camera to examine the entire colon for any signs of cancer recurrence or new polyps.
- Sigmoidoscopy: A similar procedure that examines only the lower part of the colon.
Genetic and molecular tests-
- Oncotype DX Colon Recurrence Score test: Analyzes the genetic makeup of a tumor to help determine a patient’s risk of recurrence.
- Other tumor-based tests: Some tests analyze the specific mutations in a patient’s tumor to predict the risk of recurrence.
Don’t skip colonoscopy for new blood-based colon cancer screening, study concludes
Newly available blood tests to screen for colorectal cancer sound far more appealing than a standard colonoscopy. Instead of clearing your bowels and undergoing an invasive procedure, the tests require only a simple blood draw. But are the tests effective?
A study led by researchers at Stanford Medicine concluded that the new tests are ideal for people who shy away from other colorectal cancer screening. However, if too many people who would have undergone colonoscopies or stool-based tests switch to the blood tests, colorectal cancer death rates will rise. Because the more established colonoscopies and stool tests are more effective at detecting early cancers and precancerous polyps than the emerging blood tests, their long-term impact is projected to be substantially greater than that of blood tests, the researchers found…
Weighing the options
With the current screening rates in the population, about 4% of all American adults will be diagnosed with colorectal cancer at some point in their lifetimes. Regular screening can help identify early cancers and precancerous polyps and reduce a person’s risk of developing, and dying, from colorectal cancer. The U.S. Preventive Services Task Force recommends that all adults between the ages of 45 and 75 be screened for colorectal cancer.
For decades, screening has required either a once-a-decade colonoscopy, in which a thin flexible tube with a camera is used to look inside a person’s large intestine, or a stool test every one to three years. During a colonoscopy, clinicians can not only detect colorectal cancers, but also remove precancerous polyps, which can develop into cancers…
Data show that about 1 in 3 American adults in the recommended age range have never been screened for colorectal cancer, so clinicians are hoping that new methods could encourage them to undergo screening.
In 2014, the U.S. Food and Drug Administration approved the first multi-target stool-based colorectal screening test, in which stool collected at home by a patient every one to three years is analyzed for the presence of small amounts of blood or cancer DNA. This summer, the FDA approved a new method that looks for bits of cancer DNA circulating in a person’s bloodstream. These first-generation blood-based tests do not diagnose precancerous polyps well.
Comparing effectiveness
Ladabaum and his collaborators collected previously published data on six commercially available or in-development blood- and stool-based screening tests as well as the gold-standard colonoscopy. Using this data, they modeled the relative rate of colorectal cancer and deaths among 100,000 average-risk people who used each screening approach.
Among 100,000 people who receive a colonoscopy every 10 years, 1,543 would develop colorectal cancer and 672 would die from the disease, they determined.
- For stool-based tests every one to three years (depending on test) the incidence of colorectal cancer ranged from 2,181 to 2,498 cases per 100,000 people, and deaths ranged from 904 to 1,025.
- For the new blood tests, recommended to be conducted every three years, the cases ranged from 4,310 to 4,365, and deaths ranged from 1,604 to 1,679 – about two and a half times as many deaths as in the colonoscopy group.
- Among those who receive no screening, 7,470 would develop the cancer, and 3,624 would die from it.
Moreover, when the group looked at the costs associated with each test, they found that colonoscopies and stool-based tests were more cost-effective than the blood-based tests.
“The blood tests are certainly much better than nothing, but you’ll worsen the population outcomes and raise health care costs if you see people switching from colonoscopies to first-generation blood tests,” Ladabaum said…
screening for colon cancer relapse screening for colon cancer relapse