I’m an oncologist. Here’s what I do to reduce my own cancer risk

Alcohol intake is a risk for cancer in a dose-dependent manner: the more you drink, the higher your cancer risk. Photo / Getty Images

THREE KEY FACTS

• In 2019, 40% of new cancer diagnoses in adults aged 30 years and older in the US were due to modifiable risk.
• The greatest contributor to those new diagnoses was cigarette smoking.
• While we commonly associate alcohol with cancers of the oral cavity or esophagus, by far the greatest number of diagnoses attributed to alcohol consumption was breast cancer.

Mikkael A. Sekeres, MD, is the chief of the division of hematology and professor of medicine at the Sylvester Comprehensive Cancer Center, University of Miami. He is author of the books When Blood Breaks Down: Life Lessons from Leukemia and Drugs and the FDA: Safety, Efficacy, and the Public’s Trust.

OPINION

My family history of cancer is impressive, and not in a good way.

My mom has lung cancer, and both her brother and mother were diagnosed with leukemia. On my dad’s side of the family, his father had prostate cancer and his mother had ovarian cancer. These are some of the reasons I decided to specialise in cancer when I became a doctor.

While in medical school, I also decided that - as much as possible - I would avoid behaviours that could increase my own risk of developing cancer, given the number of people in my family who had the diagnosis.

But it’s important to understand that not all cancers are associated with modifiable risk factors. A study from the American Cancer Society published in July estimated that, in 2019, 40% of new cancer diagnoses in adults aged 30 years and older in the United States were due to modifiable risk. In many cases, though, the risk of developing cancer can’t be reduced by changing our behaviour: the diagnosis is more or less a random event.

Still, here are five steps I’ve taken to reduce my own risk.

1. I take sun protection seriously

Skin cancer risk increases with age and in people with light-coloured skin. While the risk is lower in people with darker skin, it is still recommended they use sunscreen.

In medical school, I attended a lecture in which the professor showed us two photos: one of an older man with smooth, porcelain-like skin, attributed to the fact that he avoided the sun his entire life, and the other of a younger woman who spent plenty of time in the sun, her face a landscape of wrinkles. She looked far older than the man.

This was followed by a lecture on skin cancers, and the very next morning, I started applying a chemical sunscreen daily to my face and to the rest of my body when I anticipate sun exposure. (I also keep a bottle of sunscreen in my car just in case.) It’s a habit I have continued for decades.

As the Centers for Disease Control and Prevention recommends, I wear a hat, sunglasses and a long-sleeve shirt when I spend a lot of time outside, like going to the beach or on a bike ride of 30 minutes or longer, in addition to applying sunscreen with an SPF of 15 or higher.

Here’s why: in the 2019 study, ultraviolet radiation was found to be the second-largest contributor to new cancer diagnoses in men (about 6% of cancer cases) and the fifth-largest contributor in women (about 4% of cancer cases). Not surprisingly, most melanoma and non-melanoma (basal and squamous cell skin cancer) diagnoses were attributed to UV radiation.

Skin cancer risk increases with age - reflecting cumulative sun exposure - and in people with light-coloured skin. While the risk of skin cancer is lower in people with darker skin colour, it is still recommended they use sunscreen.

And of course, I never use tanning beds. Melanoma risk increases by 75% in people engaging in artificial tanning before the age of 35, and with years of use and number of sessions.

2. I keep alcohol intake at a minimum

I like to drink a cold beer when watching baseball in the summer or football in the fall. But I also know that alcohol consumption was the fourth-largest contributor to new cancer diagnoses in men (about 5% of cases) and third for women (about 6% of cases) in the 2019 study.

While we commonly associate alcohol with cancers of the oral cavity or esophagus, by far the greatest number of cancer diagnoses attributed to alcohol consumption was actually breast cancer, with over 44,000 in the United States in 2019.

But how much alcohol is too much? Alcohol intake is a risk for cancer in a dose-dependent manner: the more you drink, the higher your cancer risk. Even those who have one drink per day have a modestly increased risk of some cancers. So I keep my intake to no more than 1-2 drinks per week.

3. I don’t smoke

The good news is that people who stop smoking reduce their cancer risks substantially.

I attempted to modify my mom’s cancer risk by trying to convince her to quit smoking when I was 10 years old: at the encouragement of my fifth-grade science teacher, I replaced her Benson & Hedges cigarettes with rolled pieces of paper on which I had written “cancer sticks”. Unfortunately, my effort was futile in the face of her nicotine addiction, though I never took up smoking myself - so my teacher’s intervention worked on me.

Cigarette smoking was the greatest contributor to new cancer diagnoses in adults aged 30 years and older in the United States. Specifically, it was attributed to about 86% of lung cancer diagnoses, about 54% of cancers of the esophagus and about 51% of bladder cancers, among many, many other cancer types.

The good news is that people who stop smoking reduce their cancer risks substantially: the risk of lung cancer drops by half with 10-15 years of smoking cessation and falls to almost nonsmoker levels for those who quit by age 40. Similarly, the risk of esophageal cancer diminishes by 30% and of bladder cancer falls to 50% with 10 years of smoking cessation.

4. I exercise half an hour every day

The American Cancer Society recommends 150-300 minutes of moderate-intensity exercise or 75-150 minutes of vigorous exercise per week. Photo / Dean Purcell

I work out daily for 30 minutes. Like many, I find it hard to squeeze exercise into a busy day, so I start with it and make it convenient: I wake up a little earlier and get onto a bike machine that I keep near my bedroom while I catch up on social media. That way, no matter what direction the rest of the day takes, at least I’ve accomplished one positive thing for myself.

In a recent study of over 60,000 adults, those who exercised for two or more hours per week had a 26% lower risk of head and neck cancer, a 20% lower risk of lung cancer and an 11% lower risk of breast cancer, but slightly higher rates of melanoma and prostate cancer.

The American Cancer Society recommends 150-300 minutes of moderate-intensity exercise (such as brisk walking, or biking under 16kmh) or 75-150 minutes of vigorous-intensity exercise (such as running, or cycling 16kmh or faster) per week, citing risk reduction in breast, colon and endometrial cancers, among others.

5. I avoid sugary drinks, fast food and processed meats

Research has found an association between colorectal cancer and consumption of red meat and processed meat, as well as with low dietary fibre and calcium. Low fruit and vegetable consumption has been associated with oral cavity, pharyngeal, esophageal and laryngeal cancers.

So I try my best to eat healthy, well-balanced meals. But I’m an omnivore, and I don’t do well with restrictive diets or dietary recommendations that call for multiple servings of one type of food daily. I have cut out sugary drinks entirely. I have a fruit or vegetable with lunch and dinner, and I limit my red meat intake to once or twice per week. Most importantly, I rarely get fast food, and I avoid processed meats.