New Colorectal Cancer Screening Guidelines for 2019 and 2020
Mar 15, 2020
While you were going about your business, the American College of Physicians (ACP) released new Colorectal Cancer Screening Guidelines. And they changed the age on us. Again. What does this mean for you, if anything? And why are these guidelines seemingly being revised all the time?
It turns out that different organizations recommend different screening protocols. And all of these organizations have smart people in them. (Why can’t they just all agree?) For colorectal cancer, here are some examples of the discord:
- American Cancer Society recommends to start screening at age 45
- The US Preventive Task Force has stuck to their recommendation to begin screening at age 50
- In Canada, colonoscopy is not recommended for initial screening, while in the US the various recommendations do include colonoscopy. (The Canadians prefer stool tests or a less invasive scope called a sigmoidoscopy).
This week the ACP released a new set of guidelines attempting to clarify the issue. These guys left no stone unturned. They looked at every set of guidelines from Scotland to Canada to the USA. The age they settled on? Fifty. Between the ages of 50 and 75, the ACP recommends screening for colorectal cancer by the following methods:
- Colonoscopy. This is the granddaddy test of them all. A full-on feature film spanning the whole length of your large intestine, worse than the lowest-rated movie you’ve ever seen on Rotten Tomatoes. Fortunately, like many of those movies, you’re asleep for it. And if your internal spelunking expedition looks good, you don’t have to do it again for a long time. How long? Well, we aren’t totally sure. But 10 years seems to be a good estimate.
- Fecal immunochemical test. We like to call this “FIT”, because “fecal” anything just doesn’t sound good, and we’re already mad we typed it twice. This is an at-home that detects any blood in your stool that might suggest cancer. If it’s positive, you bought yourself a colonoscopy to see what’s going on. It’s a bit like the worst scratch-off ticket ever. If negative, it needs to repeated every 2 years.
- A third option is to do FIT every two years, and throw in flexible sigmoidoscopy every ten years. The “flex sig” as it is called, is similar to #1, but only visualizes the “terminal” (end) part of the colon and rectum. You’ll never think about airplane terminals the same way again, and we’re sorry.
So, if you’re a 45 year old with average risk (no one in your family had colon cancer), what do you do? Last year, ACS told you to get screened. This year, ACP is telling you not to!
The bottom line is that we just don’t know. The age 45 recommendation last year came from some studies that showed that the number of colon cancer deaths in adults age 20-54 was starting to tick back up again.
We don’t always know exactly why, but we do know that patterns of disease change over time. Know anyone with TB or malaria in the US? Probably not, but 100 years ago these diseases affected tons of people in this country. So we must be ever vigilant for changing patterns and revise our recommendations accordingly. The ACS guidelines took this into consideration, while the ACP guidelines focused more on the hard evidence of trials that looked at screening efficacy.
The bottom line is that on the margins – like adults age 45 to 49 – we just aren’t sure. You should discuss with your doctor, and come up with a strategy that fits your risk profile and comfort level. So, here’s to uncertainty, because that’s where we are left for you folks under 50. For 50 and up, the evidence is solid. Get screened.