Colorectal Cancer Archive

In the journals

Greater amounts of physical activity during the day are associated with lower risk of dying from cancer, according to a study published online June 18, 2020, by JAMA Oncology.

The study involved about 8,000 people, average age 70, who did not have a cancer diagnosis. Each wore an accelerometer on the hip during waking hours for a week to collect movement data.

News briefs

Having gum disease increases your risk for many health problems other than tooth loss, such as heart disease. To add to the list, a study from Harvard summarized in a letter published online July 20, 2020, by the journal Gut suggests that the microbes camping out between your teeth and gums may affect your risk for cancers of the stomach and esophagus. Harvard scientists analyzed health data from two large studies that included almost 150,000 men and women. In up to 28 years of follow-up, people with a history of periodontal (gum) disease were 43% more likely to develop esophageal cancer and 52% more likely to develop gastric (stomach) cancer compared with people whose gums were healthier. The risk was even higher in those with gum disease severe enough to cause tooth loss. The study is observational and doesn't prove that gum disease causes cancer, but it could mean that someday doctors will include a look at your gum health when assessing your overall risk. Fortunately, it's easy to prevent gum disease. The American Dental Association recommends that you brush your teeth twice per day, floss at least once per day, and get a dental exam and cleaning regularly.

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Research we're watching

Need another reason to make your oral health a priority? Researchers at Harvard's T.H. Chan School of Public Health found that people with a history of gum disease also have a higher risk of stomach and esophageal cancers. They outlined their work in a letter published online in July 2020 by the journal Gut.

The researchers looked at two large studies involving a total of nearly 150,000 men and women. They found that during the studies' follow-up periods, which ranged from 22 to 28 years, people who had gum disease had a 43% higher risk of developing esophageal cancer and a 52% higher risk of developing stomach cancer compared with people whose gums were healthier. The authors proposed some ideas as to what was driving increased risk, such as greater exposure to oral bacteria or harmful substances produced by those bacteria. The authors said more study is needed to confirm their results.

Ask the doctors

Q. I have hemorrhoids. Could this increase my risk of colon cancer?

A. In short, no. Hemorrhoids don't cause or increase your risk for colon or rectal cancer. However, the two conditions may be mistaken for one another because they can produce similar symptoms, such as rectal bleeding, itching, and pain.

The US Preventive Services Task Force has updated its lung cancer screening guidelines, to open up the screening to a wider range of people based on their age and smoking history, with the goal of detecting more cancers and reducing deaths.

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Eating a diet high in foods tied to inflammation — such as processed meat, sweets, and refined grains — is associated with many health problems, including an increased risk for colon cancer, heart disease, stroke, or diabetes. A Harvard study published online May 7, 2020, by Gastroenterology found another potential risk: Crohn's disease, a condition characterized by areas of inflammation throughout the large and small intestines. Researchers evaluated 30 years' worth of self-reported diet information from more than 208,000 men and women. Diets were scored based on foods that promote inflammation. Compared with people who had the lowest inflammatory diet scores, people with the highest scores had a 51% higher risk for developing Crohn's disease. The risk for Crohn's doubled among people who went from a low- to a high-inflammatory diet during the study. The study is observational and doesn't prove that an inflammatory diet causes Crohn's disease. But with so many other risks associated with foods that promote inflammation, it's important to eat as many foods that fight inflammation as possible. In other words, focus on whole, unprocessed foods with no added sugar — such as vegetables, fruits, whole grains, legumes (beans, lentils), fish, poultry, nuts, seeds, a little bit of low-fat dairy, and olive oil.

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First it was certain blood pressure and heartburn drugs; now some medications used to treat type 2 diabetes are being recalled because of cancer concerns. The FDA warned in late May and early June 2020 that some lots of extended-release metformin may contain unacceptable levels of N-nitrosodimethylamine (NDMA), a possible cancer-causing chemical. At least five manufacturers are now issuing voluntary recalls of the medications. But if you take extended-release metformin, don't just stop on your own. Not all extended-release metformin products are affected by the voluntary recalls, and stopping any medication that controls blood sugar can be very dangerous. The FDA advises that you check in with your doctor or pharmacist. Ask if your medication is affected by the recall; if so, ask if you should switch to another version of the drug.

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Blood testing to detect early cancer may be closer to reality than ever before.

When it comes to most cancers, the sooner they're found, the better. "Identifying cancer in its earlier stages offers improved chances for treating it before it can grow and spread," says Dr. Brian Wolpin, director of the Gastrointestinal Cancer Center at Harvard-affiliated Dana-Farber Cancer Institute.

Unfortunately, there are not reliable tools to screen for most cancers. Examples of effective screening tests that do exist now include colonoscopies that look for polyps and early colorectal cancers, as well as imaging tests like mammograms for early signs of breast cancer and chest CT scans for localized lung cancer among former or current smokers.

Research we're watching

Move your body more and skip the alcohol to reduce your risk of cancer, says the American Cancer Society in its new cancer prevention guidelines. The updated recommendations, published online June 9, 2020, by CA: A Cancer Journal for Clinicians, also recommend cutting down on sugar and red meat, based on a review of the most recent scientific evidence.

Specifically, the new guidelines say that instead of exercising moderately for 150 minutes a week or doing 75 minutes of vigorous activity, adults should try to squeeze in 150 to 300 minutes of moderate activity or 75 to 150 minutes of vigorous activity — and that the higher number should be the target. As for diet, people interested in reducing their risk of cancer should aim to eat more plants, including whole (not refined) grains and at least two-and-a-half cups of colorful fruits and vegetables each day, and less sugar and meat (specifically limiting processed and red meat whenever possible). In the past, the ACS recommended moderate alcohol intake, but the new guideline says it's better to avoid alcohol altogether if possible. People who do drink should still stick to the previous recommended limits: no more than one drink a day for women and two drinks a day for men.