colon cancer
Panel Finds Exercise May Lower Cancer Risk, Improve Outcomes
Posted on by Dr. Francis Collins
Exercise can work wonders for your health, including strengthening muscles and bones, and boosting metabolism, mood, and memory skills. Now comes word that staying active may also help to lower your odds of developing cancer.
After reviewing the scientific evidence, a panel of experts recently concluded that physical activity is associated with reduced risks for seven common types of cancer: colon, breast, kidney, endometrial, bladder, stomach, and esophageal adenocarcinoma. What’s more, the experts found that exercise—both before and after a cancer diagnosis—was linked to improved survival among people with breast, colorectal, or prostate cancers.
About a decade ago, the American College of Sports Medicine (ACSM) convened its first panel of experts to review the evidence on the role of exercise in cancer. At the time, there was limited evidence to suggest a connection between exercise and a reduced risk for breast, colon, and perhaps a few other cancer types. There also were some hints that exercise might help to improve survival among people with a diagnosis of cancer.
Today, the evidence linking exercise and cancer has grown considerably. That’s why the ACSM last year convened a group of 40 experts to perform a comprehensive review of the research literature and summarize the level of the evidence. The team, including Charles Matthews and Frank Perna with the NIH’s National Cancer Institute, reported its findings and associated guidelines and recommendations in three papers just published in Medicine & Science in Sports & Exercise and CA: A Cancer Journal for Clinicians [1,2,3].
Here are some additional highlights from the papers:
There’s moderate evidence to support an association between exercise and reduced risk for some other cancer types, including cancers of the lung and liver.
While the optimal amount of exercise needed to reduce cancer risk is still unclear, being physically active is clearly one of the most important steps in general that people of all ages and abilities can take.
Is sitting the new smoking? Reducing the amount of time spent sitting also may help to lower the risk of some cancers, including endometrial, colon, and lung cancers. However, there’s not enough evidence to draw clear conclusions yet.
Every cancer survivor should, within reason, “avoid inactivity.” There’s plenty of evidence to show that aerobic and resistance exercise training improves many cancer-related health outcomes, reducing anxiety, depression, and fatigue while improving physical functioning and quality of life.
Physical activity before and after a diagnosis of cancer also may help to improve survival in some cancers, with perhaps the greatest benefits coming from exercise during and/or after cancer treatment.
Based on the evidence, the panel recommends that cancer survivors engage in moderate-intensity exercise, including aerobic and resistance training, at least two to three times a week. They should exercise for about 30 minutes per session.
The recommendation is based on added confirmation that exercise is generally safe for cancer survivors. The data indicate exercise can lead to improvements in anxiety, depression, fatigue, overall quality of life, and in some cases survival.
The panel also recommends that treatment teams and fitness professionals more systematically incorporate “exercise prescriptions” into cancer care. They should develop the resources to design exercise prescriptions that deliver the right amount of exercise to meet the specific needs, preferences, and abilities of people with cancer.
The ACSM has launched the “Moving Through Cancer” initiative. This initiative will help raise awareness about the importance of exercise during cancer treatment and help support doctors in advising their patients on those benefits.
It’s worth noting that there are still many fascinating questions to explore. While exercise is known to support better health in a variety of ways, correlation is not the same as causation. Questions remain about the underlying mechanisms that may help to explain the observed associations between physical activity, lowered cancer risk, and improved cancer survival.
An intensive NIH research effort, called the Molecular Transducers of Physical Activity Consortium (MoTrPAC), is underway to identify molecular mechanisms that might explain the wide-ranging benefits of physical exercise. It might well shed light on cancer, too.
As that evidence continues to come in, the findings are yet another reminder of the importance of exercise to our health. Everybody—people who are healthy, those with cancer, and cancer survivors alike—should make an extra effort to remain as physically active as our ages, abilities, and current health will allow. If I needed any more motivation to keep up my program of vigorous exercise twice a week, guided by an experienced trainer, here it is!
References:
[1] Exercise Is Medicine in Oncology: Engaging Clinicians to Help Patients Move Through Cancer. Schmitz KH, Campbell AM, Stuiver MM, Pinto BM, Schwartz AL, Morris GS, Ligibel JA, Cheville A, Galvão, DA, Alfano CM, Patel AV, Hue T, Gerber LH, Sallis R, Gusani NJ, Stout NL, Chan L, Flowers F, Doyle C, Helmrich S, Bain W, Sokolof J, Winters-Stone KM, Campbell KL, Matthews CE. CA Cancer J Clin. 2019 Oct 16 [Epub ahead of publication]
[2] American College of Sports Medicine Roundtable Report on Physical Activity, Sedentary Behavior, and Cancer Prevention and Control. Patel AV, Friedenreich CM, Moore SC, Hayes SC, Silver JK, Campbell KL, Gerber LH, George SM, Fulton JE, Denlinger C, Morris GS, Hue T, Schmitz KH, Matthews CE. Med Sci Sports Exerc. 2019 Oct 16. [Epub ahead of publication]
[3] Exercise Guidelines for Cancer Survivors: Consensus Statement from International Multidisciplinary Roundtable. Campbell KL, Winters-Stone KM, Wiskemann J, May AM, Schwartz AL, Courneya KS, Zucker DS, Matthews CE, Ligibel JA, Gerber LH, Morris GS, Patel AV, Hue TF, Perna FM, Schmitz KH. Med Sci Sports Exerc. 2019 Oct 16. [Epub ahead of publication]
Links:
Physical Activity and Cancer (National Cancer Institute/NIH)
Moving Through Cancer (American College of Sports Medicine, Indianapolis, IN)
American College of Sports Medicine
Charles Matthews (NCI)
Frank Perna (NCI)
NIH Support: National Cancer Institute
Are Some Tumors Just ‘Born to Be Bad’?
Posted on by Dr. Francis Collins
Caption: Human colon cancer cells.
Credit: National Cancer Institute, NIH
Thanks to improvements in screening technologies and public health outreach, more cancers are being detected early. While that’s life-saving news for many people, it does raise some important questions about the management of small, early-stage tumors. Do some tumors take a long time to smolder in their original location before they spread, or metastasize, while others track to new, distant, and dangerous sites early in their course? Or, as the authors of a new NIH-funded study put it, are certain tumors just “born to be bad”?
To get some answers, these researchers recently used genomic data from 19 human colorectal tumors (malignant and benign) to model tumor development over time [1]. Their computer simulations showed that malignant tumors displayed distinctive spatial patterns of genetic mutations associated with early cell mobility. Cell mobility is a prerequisite for malignancy, and it indicates an elevated risk of tumors invading the surrounding tissue and spreading to other parts of the body. What’s more, the team’s experimental work uncovered evidence of early abnormal cell movement in more than half of the invasive tumors.
Much more remains to be done to validate these findings and extend them to other types of cancer. But the study suggests that spatial mutation patterns may someday prove useful in helping decide whether to pursue aggressive treatment for early-stage cancer or opt for careful monitoring instead.
Snapshots of Life: Tales from the (Intestinal) Crypt!
Posted on by Dr. Francis Collins
Caption: This “spooky” video ends with a scientific image of intestinal crypts (blue and green) plus organoids made from cultured crypt stem cells (pink).
As Halloween approaches, some of you might be thinking about cueing up the old TV series “Tales from the Crypt” and diving into its Vault of Horror for a few hours. But today I’d like to share the story of a quite different and not nearly so scary kind of crypt: the crypts of Lieberkühn, more commonly called intestinal crypts.
This confocal micrograph depicts a row of such crypts (marked in blue and green) lining a mouse colon. In mice, as well as in humans, the intestines contain millions of crypts, each of which has about a half-dozen stem cells at its base that are capable of regenerating the various types of tissues that make up these tiny glands. What makes my tale of the crypt particularly interesting are the oval structures (pink), which are organoids that have been engineered from cultured crypt stem cells and then transplanted into a mouse model. If you look at the organoids closely, you’ll see Paneth cells (aqua blue), which are immune cells that support the stem cells and protect the intestines from bacterial invasion.
A winner in the 2016 “Image Awards” at the Koch Institute Public Galleries, Massachusetts Institute of Technology (MIT), Cambridge, this image was snapped by Jatin Roper, a physician-scientist in the lab of Omer Yilmaz, with the help of his MIT collaborator Tuomas Tammela. Roper and his colleagues have been making crypt organoids for a few years by placing the stem cells in a special 3D chamber, where they are bathed with the right protein growth factors at the right time to spur them to differentiate into the various types of cells found in a crypt.
Once the organoids are developmentally complete, Roper can inject them into mice and watch them take up residence. Then he can begin planning experiments.
For example, Roper’s group is now considering using the organoids to examine how high-fat and low-calorie diets affect intestinal function in mice. Another possibility is to use similar organoids to monitor the effect of aging on the colon or to test which of a wide array of targeted therapies might work best for a particular individual with colon cancer.
Links:
Video: Gut Reaction (Jatin Roper)
Jatin Roper (Tufts Medical Center, Boston)
Omer Yilmaz (Massachusetts Institute of Technology, Cambridge)
The Koch Institute Galleries (MIT)
NIH Support: National Cancer Institute; National Institute on Aging
Precision Medicine: Who Benefits from Aspirin to Prevent Colorectal Cancer?
Posted on by Dr. Francis Collins
In recent years, scientific evidence has begun to accumulate that indicates taking aspirin or other non-steroidal anti-inflammatory drugs (NSAIDs) on a daily basis may lower the risk of developing colorectal cancer. Now, a new study provides more precise information on who might benefit from this particular prevention strategy, as well as who might not.
Published in the journal JAMA, the latest work shows that, for the majority of people studied, regular use of aspirin or NSAIDs was associated with about a one-third lower risk of developing colorectal cancer. But the international research team, partly funded by NIH, also found that not all regular users of aspirin/NSAIDs reaped such benefits—about 9 percent experienced no reduction in colorectal cancer risk and 4 percent actually appeared to have an increased risk [1]. Was this just coincidence, or might there be a biological explanation?
Cancer Cachexia: Might This Molecule Hold the Key?
Posted on by Dr. Francis Collins
Caption: Structure of parathyroid hormone-related protein (PTHrP), which has been implicated in cancer-related cachexia.
Source: The Protein Data Bank
No matter how much high-calorie food they eat or nutritionally fortified shakes they drink, many people with cancer just can’t seem to maintain their body weight. They lose muscle and fat, sometimes becoming so weak that they can’t tolerate further treatment. Called cachexia, this progressive wasting syndrome has long troubled patients and their families, as well as baffled scientists searching for ways to treat or perhaps even prevent it.
Some previous studies [1-3] have observed that humans and mice suffering from cachexia have “activated” brown fat. This type of fat, as I explained in a previous post, has the ability to convert its chemical energy into heat to keep the body warm. Intrigued by these hints, a team led by Bruce Spiegelman of the Dana-Farber Cancer Institute and Harvard Medical School in Boston recently decided to explore whether tumor cells might secrete molecules that spur similar brown fat-like activity, causing a gradual depletion of the body’s energy stores.
Different Cancers Can Share Genetic Signatures
Posted on by Dr. Francis Collins
NIH-funded researchers analyzed the DNA of these cancers.
Cancer is a disease of the genome. It arises when genes involved in promoting or suppressing cell growth sustain mutations that disturb the normal stop and go signals. There are more than 100 different types of cancer, most of which derive their names and current treatment based on their tissue of origin—breast, colon, or brain, for example. But because of advances in DNA sequencing and analysis, that soon may be about to change.
Using data generated through The Cancer Genome Atlas, NIH-funded researchers recently compared the genomic fingerprints of tumor samples from nearly 3,300 patients with 12 types of cancer: acute myeloid leukemia, bladder, brain (glioblastoma multiforme), breast, colon, endometrial, head and neck, kidney, lung (adenocarcinoma and squamous cell carcinoma), ovarian, and rectal. Confirming but greatly extending what smaller studies have shown, the researchers discovered that even when cancers originate from vastly different tissues, they can show similar features at the DNA level
