Tag Archive for: colorectal cancer

Where’s the Proof?

A series of articles and studies published recently have called into question the use of statistics in examining large health databases. It’s especially pertinent to nutrition research because placebo-controlled trials are virtually impossible.

See if this sounds familiar: eating meat is associated with an increased risk of colorectal cancer. The “association” is calculated by considering variables that may impact the development of cancer and estimating the hazard of eating various quantities of meat. Recent articles have called into question whether enough variables are being considered, because only a few people decide what else could impact the development of cancer other than meat. Then the analysis is run and the results reported.

What if they didn’t pick the correct variables or enough variables that could impact cancer? What if they didn’t use the correct statistical methods to analyze the data? That could be why one study shows fish oil lowers the risk of cardiovascular mortality and another says it does not. Let’s look at an example.

“Ultra-Processed Food is Bad”

Eric Schlosser is an author and filmmaker who wrote Fast Food Nation and made the movie Food, Inc.; Food, Inc. 2 has come out recently. As a guest on Real Time with Bill Maher, he commented that ultra-processed food (UPF) is the leading cause of obesity and other diseases, but he offered no evidence to support that position. He suggested that it was the artificial ingredients found in UPF that make us crave them and eat them without restraint. Again, no evidence.

Several epidemiological studies have suggested that UPF is related to obesity. The question that remains is how? If it’s the artificial ingredients, how do they do that? By stimulating appetite? Or turning off satiety signals? Or some other mechanism?

That data isn’t collected in most large studies. When the researchers select variables that could impact the results, are they considering the correct ones? It makes a difference because at the end of these large observational studies, that’s the question that remains: How?

The Bottom Line

There is no conclusion at this point. That’s not usually my style, but this is complicated. There are too many observational studies and meta-analyses that are being used as the foundation of medical care and health and nutrition education, because as I see it the data are incomplete. For now, there are some changes we know will work and can prove: Eat less. Eat better. Move more.

What are you prepared to do today?

        Dr. Chet

Protect Your Colon Health: Do a Test

Continuing with our examination of the study on invited colonoscopies versus usual care, what could the researchers have said to cause any controversy? Remember, the comparative rates of diagnosing colorectal cancer were slightly lower in the invited group. The controversy came when they stated that there was no difference in mortality over the course of 10 years. That suggests that it doesn’t matter whether you’re specifically asked to have a colonoscopy or get one as part of your usual care—your risk of dying from colorectal cancer, the second leading cause of cancer deaths in the U.S., is no different. As you might expect, nothing is quite as simple as it appears to be.

Invitations Don’t Mean You’ll Accept

The stunning part to me was that only 42% of the people in the invitation group accepted and had the colonoscopy. This is where going back to ask why the subjects did or did not have the colonoscopy is important. The people were not identified by name but by a randomly generated number. In order for the data to be meaningful, we need to know why the potential subjects chose not to participate.

What About Other Diagnostic Tests?

The most common test at this point is the fecal occult blood test (FOBT). This test looks at a sample of your stool to check for blood; the key is that it’s blood that’s not visible to the eye (that’s what occult means in this case). Blood in the stool can be a symptom of several conditions including anemia and colorectal cancer; the test can also be used to identify genetic risk factors for colorectal cancer.

What the test can’t do is identify those people who have adenomas, a precancerous growth. Not all adenomas become cancerous, but they can be removed during a colonoscopy and tested for cancer. The fecal occult blood test can’t detect adenomas that are not bleeding.

The Bottom Line

The thing to remember is that testing is important, whichever way you do it. Colonoscopies require the marvelous “colon cleansing preparation” that may be too hard on elderly people or those with poor health; it’s no walk in the park for anyone. The cost may also be prohibitive depending on the type of insurance coverage one has. Protecting your colon health calls for a serious discussion with your healthcare provider to find out what the best course of action is for you. Family and personal history both have a role to play and need to be considered.

The purpose of research such as this is to help you find what your path should be. But once you know it, follow it. Ignoring it may bring undesired outcomes—and the last time I checked, death is permanent.

What are you prepared to do today?

        Dr. Chet

Reference: New England Journal of Medicine. 2022. DOI: 10.1056/NEJMoa2208375

Research Update on Colon Health

If I were to take a poll, I’d wager that most people would skip a colonoscopy if there were an alternative that provided the same information on the health of your colon. The key words are “same information”—not only that, but provided the same diagnostic outcomes. Will the alternative test tell you whether you have colorectal cancer? Will it give information on the health of your colon? A recent research paper called that into question. Let’s take a look at the study published in the New England Journal of Medicine.

Researchers from several European countries (Poland, Norway, Sweden, and the Netherlands) wanted to examine the difference in outcomes between two groups. The first were a group who were invited to have a colonoscopy. The second was a group that received usual care. Simply put, the second group relied on physicals and doctor discussions to decide whether to have a colonoscopy or not. They recruited over 28,000 people from 55 to 64 years old for the invited colonoscopy and compared them with over 56,000 people who received the usual care.

After following the subjects for 10 years, they found the risk of colorectal cancer diagnosis was 0.98% in the invited group versus 1.2% in the typical treatment group. That looked pretty good for colonoscopies. But it’s what the researchers suggested in the discussion portion of the article that raised questions. I’ll cover that on Saturday.

What are you prepared to do today?

        Dr. Chet

Reference: New England Journal of Medicine. 2022. DOI: 10.1056/NEJMoa2208375

How Does Alternative Medicine Affect Cancer?

The final study this week is an analysis of survival data on people who selected only alternative medicine as treatment after being diagnosed with a non-metastatic cancer. The subjects declined any conventional cancer treatment defined as surgery, chemotherapy, radiation, and hormone therapy. Let’s take a look at this observational study.

Researchers used the National Cancer Database to identify people who selected “other unproven cancer treatments administered by non-medical personnel”; 281 were identified over a 10-year time span. They were compared with 560 randomly selected subjects who chose conventional treatment. All were tracked for an average of 5.5 years.

The results were dismal. Over the 5.5 years, those who chose alternative medicine were 2.5 times more likely to die than those who chose conventional treatment. The rates were worse for individual forms of cancer such as breast, lung, and colorectal cancer. The only type of cancer for which had no significant differences in mortality was prostate cancer; that’s to be expected as most prostate cancers are slow growing and rarely cause death quickly.

This was simply an observational study. We don’t know the types of alternative medicine used nor whether any people returned for conventional treatment when the alternative medicine wasn’t working. However, I still think it speaks volumes: If you’re diagnosed with cancer, don’t play games. Get the strongest treatment possible; if you don’t, it could cost you your life sooner rather than later.

If you want more information about the study and the place of complementary and integrative treatments if you have cancer, listen to the newest Straight Talk on Health MP3, Alternative Medicine and Cancer. Normally you’d have to be a Member or Insider to listen to Straight Talk on Health, but because this topic is so important to your health, I’m making it available to everyone if you click on the link in this memo (I’m asking you to share it only when appropriate). If you like it, that’s one more reason to join DrChet.com.

What are you prepared to do today?

Dr. Chet

 

Reference: JNCI: doi.org/10.1093/jnci/djx145.

 

Processed Meat and Cancer: The Science

In response to the headlines about processed foods and colorectal cancer, I decided to look at some of the research on cancer and colorectal cancer. Rather then write a long drawn-out article, I’m going to give you the bottom line on what I found.

  • The risk of getting any type of cancer in a lifetime is one in two for men and one in three for women (1). The lifetime risk of getting colon cancer is 4.84% for men and 4.49% for women. If the risk is an average of 18% higher by eating . . .

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