The Truth Behind Cancer Studies

I typically get an eye-roll from my oncologist whenever I present her with a ripped out newspaper article about a just-released study announcing new cancer findings.

With all the health news accessible these days, you'd think we'd be medical experts. But, in reality, the opposite is true because so much information that's reported is confusing and even incorrect.

How do you know which studies are valid? The starting point is understanding how health-related research is conducted, so I tapped my trusty source, Greg Orloff, who teaches the cancer of biology at Emory University in Atlanta, and has an award winning website about cancer (cancerquest.org).

"There's always an element of sensationalism in the media because that's how they sell their publications," Orloff says. "Consumers need to be able to interpret a study so they can factor this information into their decision-making."

He suggests the following to determine a study's validity:

1. Determine the study's purpose. Orloff says it's expensive to follow 20,000 people over 20 years.

"As a result, researchers attempt to extract as much information from a study as possible and then use the findings for multiple purposes."

A study may be designed to find out one piece of information (whether smoking increases the risk of lung cancer), but other researchers can re-analyze the same data asking different questions and come up with additional conclusions (smoking causes an increase in heart attacks).
"You need to look at the information collected and make sure that researchers are isolating the information you're interested in from other study conclusions. This is difficult to accomplish -- it's hard to analyze one single thing because humans are complex. It could be something other than what's being studied that's contributing to the outcome."
For example, let's say you're looking at the effect exercise has on breast cancer. You conduct a study involving 2,000 people and look at those who exercise 5 times a week, those who exercise 1-3 times a week, and those who don't exercise at all.
Then, you observe the rate of breast cancer occurrence over time. You may find that those who exercised 5times a week had fewer occurrences of breast cancer than those who didn't exercise at all.
But what do you think the chances are that people who exercise a lot also have a healthier diet than those who don't? So another factor -- diet, which is not what the study is about - may play a role in the study's results.
It's a matter of asking the right questions about the study.
2. Look at how the study was designed and conducted. To interpret the findings of a health-related study, consumers need to understand the nature of research and what it entails. Consider the following questions when giving credence to a study:
* How reliable is the information gathered from the participants? People can make mistakes (or not tell the truth) in recalling lifestyle choices and their family health history. This can affect a study's outcome.

* How many people did the study involve? The larger the study, the more credible the information. If the study was not conducted on a large enough population, then you should hold off making a conclusion.

* What was the length of time it was conducted? The results will differ significantly from a 5-year study versus a 20-year one.

"Often, evidence is derived from the preliminary stage -- such as 3 years into a 20-year study -- which can be misinterpreted and hyped by the press, eager to report the latest news. A longer study is better at providing the actual outcome."

* Who participated in the study? Socioeconomic and cultural variations between one population and another can impact results. A study should represent the larger population in order for researchers to make a general, relevant statement. But this is difficult to achieve.

"The challenge is how do you randomly select a population to study? Let's say you decide to study people living near a major college campus. But the problem is that a better-educated, higher-income population lives in that area, and that means they make very different lifestyle choices (such as more visits to the doctor) versus the average population. This is just one factor that will produce a bias in the study's results."

* Who conducted the study and what was their motivation? Is it to convince you to buy their product?

3. Know the difference between "correlation" and "causation."

Correlation -- is an association between two things. For example: Men who exercise have fewer incidents of colon cancer. But is it because they exercise, or that they are eating a better diet? The association between exercise and lack of colon cancer is real, but is exercise actually causing these positive results?

Causation--is a factor that leads to a specific outcome, such as smoking causes lung cancer. You can get lung cancer for other reasons, but scientists have proved that mutagens in smoking do cause lung cancer.

People often misuse those terms and misinterpret results, making a conclusion because they assume causation and correlation are the same.

4. Are studies conducted on animals relevant? Since human studies are difficult and expensive, animal studies can be beneficial since researchers know the genetics and can completely control behavior (how much daylight exposure they receive, diet, hours of sleep).

"For want of a better model system, animals are valuable," says Orloff. "People tend to dismiss animal studies, but researchers can still observe the effects of a particular treatment, which could be applicable to humans.

"At the same time, if a treatment works in an animal model, it may or may not work in humans because we're genetically designed differently."

With animal models, you need to ask if the doses that researchers are giving a reasonable amount.

5. Understand the statistics. "Studies ultimately come down to statistics, and most often, reporters and readers don't understand what those statistics mean. Statistics exist for any study with credibility.

"So, if you are interested in pursing a lifestyle change based on a study, you need to know the numbers that support the findings - is it statistically significant?"

Medical journals are a good place to find a study's statistics.

"And even if you can't interpret the data, the more information you can access, the better you are armed to ask the right questions of professionals (your doctor), who can give you the best answers."

So, despite the eye-roll, it's a good idea to check with your doctor regarding information you find in the media. They are the best source about what's true and false.

Cancer 101

Every day, it seems, I get an email from a well-meaning friend about a new cancer study concerning grapefruit juice, PET bottles, red meat...the list is endless. Or, a news article saying that mammograms and self-examination are a waste of effort.

Since I've recently received my umpteenth email about another presumable cancer-causer, I thought it was time to feature an interview I had with Dr. Gregg Orloff. Orloff teaches the biology of cancer at Emory University in Atlanta, and has developed an award-winning website that explains the biology of cancer: http://www.cancerquest.org/.

"Of all the environmental and behavioral factors that have been investigated for cancer, only a few have shown a clear link," Orloff says.

"It's difficult to make hard conclusions about certain activities and their impact on cancer because studies to-date haven't involved a large enough population or haven't been conducted for a long enough time period to offer anything definite. The data simply doesn't exist at this point."

Still, research has uncovered enough implications between particular behaviors and increased risk that it's worth paying attention to how lifestyle choices impact our health, he says. But in order to understand how behavior and cancer are related, we first need to know what causes cancer to form.

The Basics
"Cancer is ultimately a result of DNA damage," explains Orloff.

"We know that cancer is derived from a single defective cell that has multiplied. It occurs when a cell strikes out on its own, resulting in unregulated cell growth. These abnormal cells pile up on each other and form masses, which are commonly known as tumors."

Why does a normal cell strike out in the first place? What causes it to become cancerous?

It happens when a particular set oif genes in a cell are altered by mutagens. And, this is where lifestyle behaviors may play a role in cancer. Mutagens enter the human body by means of inhaling, ingesting and absorbing.

They derive from:
* Chemicals in the diet -- For example, charred meat from grilling (the burning process) can cause the formation of chemicals that are thought to be mutagenic.

* Infectious agents -- A problem can occur when a virus actively alters the cells. For example, cervical cancer may result after infection with the Human Papilloma Virus...a viral infection.

* Chronic infections - Cancer can result in response to an infectino. For example, hepatitis has been associated with liver cancer. When cells are killed by infection, they need to be replaced constantly, so there are high amounts of cell division occurring in these tissues. In addition, the body's immune response to fight infection is producing chemicals that can cause mutations.

* Chemicals in the envioronment -- These can be absorbed or inhaled, such as smog and industrial waste.

In other words, every time you expose your body to a cancer risk -- eating buned meat, inhaling cigarette smoke or absorbing coal tar -- mutagens enter your body. And chemicals that are mutagenic can cause DNA damage.

The Luck Factor
If we all take in mutagens, then why does one person develop cancer over someone else?

"In order for a single, normal cell to turn into a cancer cell, it must acquire five to six different changes from mutagens. So, it's a cumulative effect," says Orloff. "Two people can be exposed to the same mutagen, but in one person, the cell dies or remains the same, while the other perosn acquires a mutation in an important gene and develops cancer.

"That's why you see some people smoke their entire lives and not get cancer, and others who 'do all the right things' develop cancer. Luck plays a big role as to who gets cancer and who doesn't. "

In the Genes
There are genetic components to cancer, as well.

"A person can inherit defective genes -- such as BRCA1--which by itself doesn't necessarily cause cancer," Orloff adds. "But a defective gene can increase your chances that some important key genes will be affected by a mutation, giving you a higher risk for cancer."

Another genetic factor that can impact whether one person develops cancer versus another is possessing better DNA repair genes, which respond to DNA changes differently.

In addition, the way your body processes toxins can affect your chances of getting cancer. For example, the liver has enzymes to process and eliminate toxins -- making them soluble so they can be excreted. But this detoxification process can convert a chemical into a mutagen.

Consequently, two people may be exposed to the same risks, but their bodies may process toxins differently.

Risky Business
Whatever your body's genetic makeup, DNA can be damaged by certain behaviors.

The following factors are known to have an associated risk of cancer because of their mutagenic properties:

* Smoking -- Full of mutagens, smotking as well as second-hand smoke is connected to almost all cancers.

* Sun damage -- UV rays are mutagenic and have been proven to cause skin cancer.

* Diet & obesity -- Obesity carries an increase risk of breast and colon cancers. Certain diets can alter the level of growth factors and nutrients (protiens, lipids, sugars) in the blood, which, in turn, can stimulate normal cells to become cancerous, or cause existing cancer cells to grow.

* Alcohol -- Particularly a risk factor for breast, colon and esophageal cancers, alcohol is toxic and must be detoxified, causing stress on the body. The detoxification process can cause DNA damage.

* Medications -- Certain drugs can potentially cause a problem. For example, female children of women who took DES (now outlawed) while pregnant have higher incidences of cervical and uterine cancer.

Healthy Choices
On the other hand, there appear to be certain behaviors that may help reduce your risk of cancer:

* Exercise - In some studies, exercise has been shown to have positive beneficial effects on breast and colon cancer. The benefits of exercise may be due to a wide variety of effects, ranging from enhanced immune system function to increased GI motility.

* Diet -- Overall, a well-balanced diet with fruits, vegetables and nuts is beneficial. Specifically, foods that contain antioxidants (such as leafy green and cruciferous vegetables) have cancer fighting possibilities.

This is because our bodies produce oxygen radicals, which are highly reactive molecules in cells that act as mutagens and can cause DNA damage. Antioxidants act as interceptor missiles, neutralizing oxygen radicals before they affect DNA.

In addition, studies have indicated that Vitamin D, selenium and calcium might potentially prevent or limit cancer growth.

"None of these things, alone, offers a huge reduction in cancer risk," warns Orloff. "But we know enough from studies to advise people to take care of their body."

The Bottom Line
"There's no holy grail in that if you do this set of behaviors, you won't get cancer," says Orloff. "All you can do is limit your risks.

"It's like avoiding a car accident," he says. "You can limit your risks by wearing a seat belt, not driving late at night, and not driving while talking on the cell phone. But all these things still can't guarantee that you won't get killed in a car accident."

"The same goes for cancer. Individuals have to decide what risks they want to live with."

Off Balance

After breast reconstruction, I found myself falling over easily...and often. In fact, I lost my balance so much that I feared I had developed a brain tumor. Not that I obsess...

It wasn't until I heard about other women with breast reconstruction who also experienced the loss of balance after surgery. I finally surmised that because we had our core muscles cut, we no longer have the abdominal strength to balance us.

Therefore, if you're slipping and falling frequently, fret not. Instead, sign up for a strength training class to build back your core. Since I've been working out with my personal trainer -- who, incidentally had me hauling concrete blocks and stepping up and down on a bus stop post last week -- I realize I've been stumbling less.

It's painful, but it will keep you from injury in the long run. So, go find some concrete blocks and start moving.

Resiliency

I was slogging through rush-hour traffic in Atlanta the other night while listening to Terry Gross with"All Things Considered" interviewing Elizabeth Edwards about her just-released book, "Resilience."

At the interview's end, Gross asked Edwards how she defined resiliency. Edwards' answer was so profound that I practically drove off the road trying to write it down. Since I haven't purchased her book yet, I will paraphrase what Edwards said:

"Resiliency is accepting the new reality of your life after loss-- and live it fully -- rather than long for the past and what it held."

If ever there was a quote for cancer survivors, this is it. I don't know about you, but sometimes I am wistful of life before cancer -- without all the surgery scars and missing pieces...when I was stronger and more flexible...when I had eyebrows (sigh)...when I could remember every detail (before chemo deleted my brain)...when I was innocent and naive, thinking I was invincible and immortal.

I don't obsess about these things, but every now and then, I get frustrated trying to be the "old me." And that person doesn't exist.

The new reality is an older, scarred, wiser woman who knows first-hand the body's limitations and the eventual result of death.

On the other hand, she also knows she has more courage in the face of fear than she ever imagined. That she doesn't take a single day of life -- or a single relationship -- for granted. That every day counts. Every interaction. Every choice. Every action. It all matters.

She also knows that she is loved far more than she ever realized. She knows that pain and suffering produce depth and insight. She understands what's truly important and what needs to be discarded or not taken so seriously.

Life after cancer is my new reality. I can never run away from or ignore what has happened to me. I can't go back and recapture my youthful self.

But, as Edwards points out, resiliency is the ability to "live fully" in your new life. That takes on a different meaning for each cancer survivor. For me, it's accepting my physical limitations, while at the same time, appreciating that I have a better grasp of what is true and valuable.