Always Tell Me the Odds

Most people don’t understand the odds.

Many folks struggle with statistical probability. Take the birthday problem… In a room of 23 people, there’s a 50% chance two of those people have the same birthday. But if you have 75 people in a room together, the chance of two of them sharing the same birthday is 99.9%. Reaching a nearly 100% probability with just 75 people seems crazy… Surely you need more people, right? But it’s statistically correct!

In the world of investing, few folks really understand the statistics behind trading. Many people neglect the importance of calculating beta, which measures the risk of your portfolio (or a portion of it) against the market’s risk.

Doctors also have a hard time understanding statistics…

Doctors don’t understand statistical calculations like number of patients needed to treat to cure just one or percentage of false positives… Both are necessary to understand to make sure you get the proper care.

But there’s another example out there that I’ve heard repeated: “I already had cancer and survived. That means the odds I’ll get another cancer are low.”

That kind of thinking isn’t just wrong… it could be deadly.

I’m not talking about the recurrence of your original cancer. That depends on a number of factors, including the size of the tumor, the type of cancer, how far it had spread, and how old you were at diagnosis (younger folks have a higher risk of recurrence).

I’m talking about getting a new form of cancer after beating an original one. Imagine beating bladder cancer only to get lung cancer two years later.

This kind of second cancer diagnosis affects about one in six cancer survivors.

If you or a loved one has already had cancer, you need to understand your risk. Increased risk for another cancer depends on three things: treatment, location, and underlying cause.

1. Treatment. Certain types of treatment for cancer actually cause cancer as well – radiation in particular.

Radiation works to kill cancer cells because it permanently damages the DNA within the cancer cells. But the problem is that some healthy cells also get hit with radiation. And sometimes these healthy cells with damaged DNA become cancerous. Remember, cancer forms when the DNA in a cell won’t stop replicating. The cells keep dividing because the part of the DNA that usually stops replication is broken or missing. For example, women treated for Hodgkin’s lymphoma with radiation have an increased risk of breast cancer.

Similarly, some forms of chemotherapy may also contribute to new cancers. That’s because they also damage cellular DNA. One class of these drugs, called alkylating agents, are known to cause leukemia. Other classes also increase risk of leukemia, but not as much.

2. Location. The location of your original cancer may raise your risk of other cancers. That’s because of something called “field cancerization.” Basically, this means that the tissue in the area of the original cancer may still be prone to future cancers. That includes nearby tissues as well. So, for example, if you get cancer of the esophagus, you have a higher risk of laryngeal cancer. That’s partly because these tissues are so close to one another, but also because the factors that led to the original esophageal cancer (like smoking) also affects the larynx the same way.

Related to this is the type of cancer. In one review from UCLA, researchers scoured a database of more than 2 million cancer survivors. They found that 73% of folks who developed a second cancer had one of four primary cancers: bladder, breast, colon, and prostate.

3. Underlying cause. Usually, you’re at a higher risk for a second cancer based on the underlying factors for the first cancer. Remember, cancer is a multi-factorial disease. That means it usually isn’t just one thing that causes the disease… It’s almost always a combination of things like diet, lifestyle, age, and genetics. Some of these factors may increase your risk.

Certain cancers, like breast cancer and colon cancer, have a stronger genetic component.

Despite having an increased risk for a second cancer, you can still lower your risk by following basic general cancer avoidance tips. These include things like improving your diet, losing weight, and only enjoying alcohol in moderation. You can read more about these in my book, The Living Cure. If you’re a subscriber to Retirement Millionaire, click here to read it. If you aren’t a subscriber, you can buy a copy  here.

Although you can’t control all of the risk factors for cancer, you can take steps to prevent some of them. And understanding your odds will go a long way to catching cancer early.

What We’re Reading…

Here’s to our health, wealth, and a great retirement,

Dr. David Eifrig and the Health & Wealth Bulletin Research Team
June 25, 2019