Reducing the Risk of Breast Cancer Recurrence

Anyone can develop breast cancer regardless of gender or sex assigned at birth. Wondering how to reduce the risk of breast cancer recurrence is a common concern among those who have had early-stage breast cancer. After all, it's thought that 20% to 30% of these cancers will come back (recur) at some time. Certainly, breast cancer treatments can reduce the risk of recurrence, and therapies such as chemotherapy, hormonal treatments, HER2 targeted therapies, bisphosphonates, and radiation have prevented many recurrences.

Yet there are also things you can do on your own that may raise the odds in your favor that your breast cancer will stay at bay. Maintaining a healthy weight and exercising may seem obvious, but practices such as addressing sleep issues, increasing the time you go without eating between dinner and breakfast (intermittent fasting), and more may have benefits for both breast cancer survival and general good health.

Breast Cancer Recurrence

The importance of reducing the risk of breast cancer recurrence (when possible) cannot be understated. Most people who develop metastatic breast cancer (stage 4 breast cancer) did not have metastatic disease at the time of diagnosis. In fact, roughly 94% to 95% of people with metastatic breast cancer were initially diagnosed with an early stage breast cancer (stage I, stage 2, and stage 3) that later recurred. Metastatic breast cancer, in turn, is responsible for the vast majority of breast cancer-related deaths.

Recurrences Can Occur Far Beyond the 5-Year Mark

Unlike the common perception that people who have survived for five years are "cured," we know that some breast cancers, particularly hormone receptor positive (estrogen receptor positive) breast cancers, can recur many years and even decades later. In fact, estrogen receptor positive early breast cancers are more likely to recur five years to 10 years after diagnosis than in the first five years.

A 2017 study in JAMA looked at over 62,000 cisgender women with estrogen receptor positive breast cancer over a period of 20 years. The women all received endocrine therapy (tamoxifen or an aromatase inhibitor) for five years and were free of cancer when they stopped their medication. Over the next 15 years (from five years post-diagnosis to 20 years post-diagnosis) a steady number of these women developed distant recurrences of their cancer.

Recurrences sometimes occur locally in the breast, or regionally in nearby lymph nodes, but far too often are distant recurrences; recurrences that show up in distant regions of the body such as the bones, lungs, liver, brain, or other areas. Once a distant recurrence occurs, breast cancer is no longer considered "curable" and the median survival rate of stage 4 breast cancer is only three years with treatment.

Looking at these statistics can be disconcerting at best, but there are things you can do—some quite simple—that may help to reduce your risk of recurrence, and subsequently the diagnosis of metastatic cancer.

Reducing Risk of Recurrence

There are a number of myths regarding what may reduce the risk of breast cancer recurrence, as well as evidence-based information that is easily overlooked. We will look at measures that may reduce your risk based on credible studies, as well as practices that are unclear that you may wish to discuss with your oncologist.

In some cases, though the benefit on recurrence risk is still not clear, your quality of life may be improved. And living well with cancer is as important as extending your life with cancer.

Before talking about measures that may help lower recurrence risk, it's important to not add to the stigma of the disease. Some people do absolutely everything right and their breast cancer recurs anyway. Similarly, some people eat poorly, smoke, and drink heavily and their cancer never recurs. While you may be able to decrease your risk of recurrence to a degree, dealing with breast cancer is dealing with a mutated clone of cells that doesn't think or follow the rules.

Exercise

Exercise or increasing physical activity as a way to reduce breast cancer recurrence has been mentioned so often that it's easy to become immune to the news. Isn't exercise cited as a remedy for almost anything? And if you're coping with the cancer fatigue that can last for years after treatment, thoughts of upping your activity may have you jumping to the next item on this list.

Yet, of all measures to reduce recurrence risk, physical activity has the greatest amount of evidence to date. In fact, if exercise could be bottled and sold as a drug, it's effectiveness on the risk of recurrence would likely put the price tag in the range of a monthly mortgage payment—or more.

What physical activity is best? Given the number of New Year's resolutions that are broken, and the rate at which people fall away from health clubs, perhaps the best exercise is one that you will continue doing over time. Think of the activities you enjoy the most. For some people it's gardening. For others, it's rock climbing. And walking is usually readily available and can be enjoyable.

If you can find a partner to be active with—all the better. Not only does this increase your accountability to continue, but some studies suggest that greater social activity is associated with better breast cancer survival.

Maintain a Healthy Body Weight (or Reduce Weight)

Maintaining a healthy weight (or losing weight if needed) appears to lower the risk of breast cancer recurrence. If you've been frustrated in attempts to lose weight in the past, it may be encouraging to know that some other practices on this list are associated with weight loss, not just exercise, but intermittent fasting, and even upping the fiber in your diet to improve the diversity of the bacteria in your gut.

Have Your Vitamin D Level Checked

While there has been some controversy over vitamin D levels and breast cancer, some studies have found that people assigned female at birth who have low 25-hydroxyvitamin D levels have a higher recurrence risk. The benefits of vitamin D, however, go beyond reducing recurrence, and getting adequate vitamin D may improve your quality of life while living with breast cancer.

Many people ask about whether or not they should use a supplement, but fortunately, a simple blood test can determine your levels, and whether they are deficient, low normal, or adequate.

Getting vitamin D via dietary sources is challenging, at least to get the optimal 2000 IU/day recommended by some (the levels that appear to be beneficial for people with cancer are often significantly higher than those quoted on daily requirements).

Sunshine is also a source of vitamin D, though excess sun exposure is important to avoid for other reasons. (Spending 15 minutes in the sun in summer apparel without sunscreen on an average day can result in the absorption of up to 5,000 IU of vitamin D).

If a healthcare provider recommends a supplement, it's important to purchase a good product to reduce your mercury exposure. And, too much of a good thing is not better. One potential side effect of taking excess vitamin D is painful kidney stones.

Intermittent Fasting (Prolonged Nighttime Fasting)

The concept of intermittent fasting, or at least the variety in which you avoid eating for an extended period of time at night, has become popular recently as it appears to help with weight loss. Though it may be looked at as a "diet," it's likely the way our ancestors ate for many years before we had food available at all hours.

A 2016 study published in JAMA looked at the risk of recurrence in people with early stage breast cancer over a seven-year period. In this study of over 2400 people, those who "fasted" for 13 or more hours overnight had a 36% lower incidence of breast cancer recurrence than those who went less than 13 hours without eating.

In addition to a reduced risk of recurrence, those who practiced prolonged nighttime fasting had significantly lower HgA1C levels, a measure of average blood sugar over a period of three months. C-reactive protein levels (a measure of inflammation) and body mass index (BMI) were also lower in the nighttime fasting group.

Eat a Wide Variety of Healthy Foods

According to a 2017 review of studies to date, people with breast cancer who eat a diet rich in vegetables, fruits, whole grains, fish, and poultry (vs. a diet high in sugar, refined grains, high-fat foods, and especially processed meats) have better survival rates. There are many phytonutrients (plant-based chemicals) in the foods we eat, several of which have anti-cancer properties. That said, it's likely that the combination of nutrients found in these foods that's key, rather than any particular food.

To understand this, it helps to realize that cancer cells are "smart." Unlike the popular conception of cancer, tumors are not unchanging clones of cells, but continually develop new mutations. Some of these mutations help a tumor grow. Some help a tumor avoid death (apoptosis). Others help a tumor spread, or suppress the body's attempt to eliminate the cells (the immune system). Just as tumor cells have many ways to continue their growth (even when hidden), a combination of healthy nutrients gives us the best opportunity to stay as healthy as possible.

Fiber and Your Microbiome

A plethora of studies have recently looked at the role of gut bacteria (the gut microbiome) in health. There is evidence that both the type of bacteria present in our guts, and the diversity of those bacteria, play a role in our everything from our ability to lose weight, our mood, and even how we do with cancer. This has given rise to a multitude of products to attempt to restore the microbiome called probiotics.

Unfortunately, at least for those who have not been on antibiotics, probiotics may not be the way to go and eating a healthy diet may be key. While we don't have many studies looking specifically at breast cancer, the composition of the gut microbiome has been found to correlate closely with the response to immunotherapy drugs for cancer. What correlated the most with a response was the variety of bacteria (diversity) rather than any particular strain, and it's thought that probiotics may even reduce the diversity of gut bacteria via dilution. So where does this leave us?

The science on eating to improve the types of gut bacteria you have, as well as their diversity is relatively new. The one thing that seems to consistently help, however, is fiber. Fiber (both soluble and insoluble) may be considered a "prebiotic" or the food that feeds the bacteria in our guts. Good choices include foods such as leeks, onions, properly prepared garlic, bananas, avocados, and other delicious foods.

Limit Alcohol Intake

It's now known that alcohol can increase the risk of breast cancer, and even moderate amounts of alcohol may raise the risk of recurrence.

Address Any Sleep Problems You Have

According to a 2017 study, cisgender women who experience regular sleep difficulties, as well as those who have a prolonged sleep duration (defined as nine or more hours vs. eight hours of sleep) have a greater all-cause as well as breast cancer mortality rate.

There are a number of different types of sleep disorders, and these, in turn, are often addressed in different ways. For starters, practicing good sleep hygiene habits can sometimes resolve minor sleep problems.

If problems persist, however, talking to a sleep expert may be in order. We often think of sleep as inconsequential (other than feeling poorly the day after a poor night's sleep), but given the link between sleep disturbances and survival it might be considered as important as some of the treatments we use to battle the disease.

Practice Stress Management

It seems that nearly everyone is stressed these days, but that stress may not be a good thing for breast cancer survivors. In mice, stress appears to raise the risk of recurrence, though studies on humans aren't as clear. We do know that stress can result in the release of the stress hormone norepinephrine. Norepinehrine, in turn, has been found to stimulate angiogenesis by tumors (the formation of new blood vessels that allows tumors to grow) and may hasten metastases (the spread of cancer).

Regardless of the role of stress in survival, however, it simply feels bad to be stressed. Take a moment to learn about stress management, some techniques for quick stress management, and brainstorm ways you can permanently reduce the stressors in your life, ranging from toxic relationships, to a cluttered home, to self-defeating thoughts.

Be Mindful of Your Environment, Including Household Chemicals

It's long been suspected that environmental exposures, including the chemicals we are exposed to in everything from household cleaners to cosmetics, may play a role both in breast cancer risk and recurrence. While it's difficult to study (you can't expose one group to a potentially harmful chemical to see if it indeed causes harm), we are learning that practicing caution is wise.

A 2017 review looked at the evidence to date connecting breast cancer and the environment. Some compounds, such as PCBs (polychlorinated biphenyls), may raise the risk of recurrence. Others may alter the regulation of genes involved in cell growth, apoptosis (cell death), and much more. Endocrine disrupting chemicals (such as parabens and phthalates) can mimic the function of hormones in our bodies, and it's well known that the hormone estrogen should be avoided to reduce breast cancer recurrence, at least for people with hormone positive tumors.

There is a great amount of information out there of varying degrees of concern, but the important thing to note is that it's relatively easy to avoid concerning chemicals (or those that prove to be of concern in the future). Most household cleaners can easily be replaced with baking soda, lemon juice, and vinegar (and it's cheaper as well).

The environmental working group has a website (Safe Cosmetics) where you can search on thousands of personal care products (which are given a grade from 1 to 10 based on toxicity). And adding a few houseplants to your home can help to absorb many indoor air carcinogens; with indoor air thought to be more of a concern that outdoor air pollution.

When you're living with breast cancer, you can't wait a few decades to see if studies conclusively show a chemical to be suspect. But even if all turn out to be harmless, reducing your exposure can free up space in your cupboards, save you money, and even be aesthetically pleasing today.

A Word From Verywell

The potential for breast cancer to recur is frightening, and knowing that there are at least a few things you can do yourself (in addition to using medications prescribed by your oncologist) can sometimes help you feel empowered in your journey. Most of the practices discussed aren't earth-shattering and won't require an overhaul of your life. Fortunately, aside from the chance they will reduce the chance you have to face cancer again, these practices can also help you experience the best quality of life possible today.